*Hydrogen? Explosion risk? Why not lithium? Parts list?* !! FAQ HERE !! Update video: th-cam.com/video/IPXNGt6NfsU/w-d-xo.html Stream discussing some of these: th-cam.com/users/live9JOuYWRu3h4?feature=share *What about Hydrogen?!* A single battery at float charge has very slow rate of offgassing. If the battery released enough gas to be an issue, it would be dry in weeks, as would every other battery ever connected to a battery maintainer (which defeats the purpose entirely). This is one battery in a 1960s building with significant air exchange, not a bank of batteries under heavy cycling in a hermetically sealed bunker. Yes an AGM would be safer, and is a possible future retrofit. *Modified sine wave will destroy your computer!* My computer's PSU is rated for use on modified sine, according to the manufacturer on the official FAQ. Not all brands or models give that assurance. *The battery will spray acid if it suffers a major failure!* Even a sealed or AGM battery will vent under those conditions, though random catastrophic failures are very rare without external causes such as mechanical damage, short circuit, or extreme overcharging. *What about LiFePo4 / Lithium?* Higher performance but expensive and needs separate battery management; planned for a future version 2 of this project! *Y'know, there's a thing called a deburring tool instead of a utility knife...* I had one. Discovered it was missing when I went to do that stage of the project and realized just how many holes I had to drill. I have since replaced it. And gotten a step drill bit as well. *The fan is blocked! There's no airflow!* Fan has more clearance than first appears. Compare position of fan intake and the velcro at 27:46 and position of velcro and the channel in the battery box lid in the side view at 30:15. Almost as if I planned the placement! Not as effective as open air, but still plenty. *Just buy a huge power bank with built in inverter!* Power banks with UPS functions are neat, but every one I've seen linked so far has abysmally slow transfer time of 30ms, which would guarantee my computer shutting down during the switch. Also, units with comparable runtimes get very pricey, approaching 4x the cost of this project. If you have suggestions, please let me know. At a future point with more budget, I'd consider doing product reviews. *How long does it take to charge?* It will get there. Eventually. The charger in the UPS is a maintainer more than anything for a battery of this size. Significant discharge will require a boost with external charger. Adding a better charger is another potential future upgrade. *Why didn't you start with a top of the line high power UPS?* I found this one for free in a scrap pile in the stairwell of an office building. I was either going to analyze why it failed or replace the internal battery. Then got annoyed enough at a power outage to try strapping a car battery to it and seeing what it could do. Results were better than expected, so I turned it into a full project. Of course it's not perfect, but it does do what I asked it to do, and I got a cool video. *Why keep the alarm buzzer?* I wanted the option to have the alarm. But also an option to turn it down. A latching, auto reset mute circuit would have been a cool alternative where could just press a button to silence the alarm and it would stay off until the next power loss event. *Ew the music!* Agreed; I could have done better and I'm working to improve future content. If it bothers you that much, nobody is forcing you to watch :) *Parts list??* Here you go! Read datasheets and verify before ordering. I take no responsibility for any property damage, injury, etc. arising from attempts to replicate this project. P1 | PTN16-D01115K1B1 | 1k Potentiometer 0.125W Any similar part will work D1 | 1N456ATR | General Purpose Diode 30V 0.5A Any similar part will work Qi | 2N4403TAR | General purpose PNP transistor 40V 0.6A hFE 100 Any similar part will work Qm | IRLZ44NPBF | N-Channel MOSFET 55V 47A Threshold 2V Overkill for this application; any similar part will work C1 | EEU-EB1E101SH | Aluminum Electrolytic Capacitor 100uF 25V Any equivalent part will work R1, R3 | CF14JT1K00 | 1k ohm 0.25W Any equivalent part will work R2 | CF14JT560K | 560k ohm 0.25W Any equivalent part will work
Nice preemptive for all the self-righteous know-it-alls. I have almost a dozen old school and newer UPSs and have wanted to do this since the first one. Am saving this video for a template to start from.
Nice. We could easily use those "drop in lead replacement" LiFePo4s with the built in BMSs yeah? I have some spare, and an old rack mount UPS that could be put to good use, although I think it may be 48v and I think my lithium's only handle 2S chaining. Hmmm 🤔
@bc4yt Yes, though I would mod in a dedicated charger circuit when changing battery chemistry and make sure to follow battery manufacturer's application instructions. Integrated BMS can only see what's happening inside that single battery, so could be overwhelmed if a problem happens to another in the chain.
When the battery can dump nearly a thousand amps into a fault, things get rather exciting. Getting or building a bench supply is on the long list of things to do.
@@MetaphysicalEngineer Agreed. Had a motor driver fail SS and in the few seconds it took me to pull the batteries it desoldered almost every connector and stripped every wire in the chain, and that was likely only ~200A. When the battery can weld a wrench across itself, you take extra precautions 😅
Great project. I did this exact same thing a few years back (minus the fan driver circuit). I ran into a problem that you will probably run into as well. The batteries in these UPS devices are AGM (absorbed glass mat) but the boat/car batteries are FLA (flooded lead acid). I had a problem where the float charger in the UPS would basically boil the FLA batteries dry and destroy them. I found out that the charger was trying to overcharge the FLA batteries. The "full" voltage that the float charger in the UPS I had was 14.5 volts due to it using the AGM battery. This is too high for a FLA batteries. They should float about 13.5 volts. I could not find any way to adjust the float voltage in the charge circuity so I gave up on the project, I just went through too many batteries to make it worth it. Another thing I found was that the FLA batteries off-gas quite a bit while they are charging. At first I had the entire setup inside the house, but things in that room started rusting and the I started getting complaints about the smell (the off-gas is also explosive. It's hydrogen gas) so I moved the batteries outside and ran the charge wires through the wall through and existing hole. You might look on your APC board and see if the float voltage is adjustable. Just my opinion and my experiences.
Being more expensive, AGM batteries in a UPS application would be uncommon. Typically you will find sealed gel-cells in the commercial market, which you have to be even gentler with.
Interesting that yours ran the charge voltage so high. 14.5V is very high even for an AGM type; typically I see 13.8V listed for AGM float at 25C. Constant 14.5V will cause significant offgassing, while at 13.5V offgassing is minimal. 30:06 is where I show the final product, including float voltage and testing with my computer as load.
@@MetaphysicalEngineer thanks for the reply. My current Trip-lite has two ES7-12 AGM batteries in it. I just replaced them. It was not an expensive unit, but came with AGM batteries. It’s the Trip-lite model SMART1300LCDT. So there is that. Anyone who is thinking of doing this mod should pay attention to what the charge voltage is for the batteries you are replacing with FLA.
Always check the contacts on these older UPS units, over the course of years they can start to subtly corrode then heat-up and corrode even further. I had one getting to the point I heard faint arcing, the problem connector was immediately obvious, discolored and pitted metal on the contacts(on the high-current LV side of the transformer interconnect), The wire guage was too big to fit the holes present, so used forked spade terminals to repair it and cut off one side of each spade to use as through-hole, soldered those in, checked thermal camera, and have been good ever since. This is one of the first UPS units I ever bought 15+ years ago and it's still going strong. Each time I've tried to replace it, it keeps outlasting it's replacements.. one lost it's mind and exploded it's push-pull FETs randomly one night, the other started kicking the GFCI at when it performed it's sporadic self tests, never a dull moment.
I'll keep that in mind about failure of those connections, especially if this unit sees significant use. I already plan to do inspections now and then. Nice job bringing your unit back to life, and quite funny how it seems determined to outlast everything else you buy!
8 years ago, I lost the power drop and breaker panel from my small mountain house during a landslide. (As well as many other things!) It took a year and a half to get everything back on the grid. In the meanwhile, I took the 650 model of that UPS, bought 6 golf cart batteries, brought out some heavy leads from the UPS, tied the batteries up with an external 60A charger and ran all the house lighting (LED) cable modem, router, pico cell site and 32" TV/monitor and laptop from it for about 16 months. Charging during the day with a small inverter generator. Worked well for all that time, never an issue. After I was back on the grid, pulled the UPS apart. No signs of heat or component stress whatsoever, still worked great. Maybe pulled 20-30W at night, max maybe 200 during the evening. Carried me well for those several months. Now I've got 20Kwh LFeP04 battery and a 3000W inverter/ups/charger which can handle everything for a few days. (mtn folks lose power a _lot_) But that little APC did great! The transformer based ones are very solid.. Good vid!
Wow that's quite the experience! Glad you were safe! Sounds like these units are quite tough; I wonder what the inside of the transformer windings on your unit looked like as those seemed most likely to be stressed long term. Wise move to have ample backup power where you live it seems. Hence my frustration that my place here in the suburbs gets such unreliable power when we don't have landslides and ice storms and such.
The transformer had no discoloration of the bobbin plastic at all. Early on, I tried loading it down to almost ratings and checked external temps carefully, seeing almost no rise. My usual "hi" load would be about 200W, most of the time more like 80-100W. Small 32" LCD TV, laptop, all LED lighting. Modem, router and pico cell. After 16 months + continuous running not even any really hot resistors or anything. (I've been a tech for (gag) 50+ years now, and always crazy about batteries and power systems.) Since those days, my loads have increased, 50" TV/monitor, SFF desktop PC (10 years old. Really have to swap in the new Ryzen system, but lazy...) added a Starlink sat setup so that when it really gets ugly up here, power, comms and everything down, I can still communicate. Does draw 60-80W, tho, it seems) Current base load about 200-250W, more like 500W +refer/freezer for max. (70-80w freezer, cycling, 80w refer compressor cycling/400w defrost cycle) As of Thursday, all my 'critical' circuits here have been cut over to the SunGold inverter/charger and the 20KWh LiFeP04 setup. Utility has an outage scheduled for all day Wed, will see if the house systems even notice. If I'm frugal, can get around 4 days runtime. Have many hour/multiple day outages at least a few times a year here. Redwood forest, many trees. Refer, freezer and microwave now added to the system. Surplus, quality LiFe batteries are getting to be pretty good deals! Enjoy your little APC! @@MetaphysicalEngineer
exactly yep . nice engineering , but the apc max 200 watts isnt enough power and board/mosfet will eventually fail ..... better and easy to buy 1500-2000 watt inverter amazon etc $130 bucks and run 1 lithium 100amph and 2 decent size lead marine batteries mixed --(yes together) they work great together, compliment each other and many boat guys do it , then you have mucho power .
Indeed! I looked for mine when I realized how many holes I had to drill and how tough the burrs were, but it wasn't anywhere it should have been, and I haven't used it in a while. Watch me find it tomorrow when I'm searching for something else!
@@MetaphysicalEngineer I always said my shop is infested with Gremlins. They love to hide things. Their neatest trick is hiding the tool I laid down beside me two seconds ago.
@@baldeagle5297My shop floor gobbles up everything that drops on it, disappears for life. Most of all seems to like those screws and nuts that are of the typical nonstandard size.
@@MetaphysicalEngineer The style of deburring tool I have would work reasonably well here as well--I don't know the name for the style of it, but I am thinking it's different from the "pen-style" type referred to by willusher3297. Good for metal and softer, it uses curved/S-shape blades pivoting on an axis in the tip of a plastic handle. It comes with three different blades and you can swap them out: one for steel, aluminum, and plastic, another for brass and cast iron, and another for "...straight edges on almost all materials." Extra blades stored in handle. It's a Blue-Point DEBUR 300, though perhaps multiple companies have made it. That said I finally read your reply after typing the above and see that you have a pen-style or at least a deburring tool already. Ah well. :) Update: I see in another reply that you've already acquired a replacement.
A most honestly an 'Engineered' solution to this problem. Step by step what I would do myself, but also being honest, a much more presentable "product" that I would have likely done myself, if for my own use. Currently have a slightly smaller APC that I'm going to perform a similar upgrade to. Thanks for the work!
Good luck on your project, and please don't forget the fuses! Aesthetics were partly for the video, and partly because my lady and I will have to perceive the end product in the bedroom/office, so an ugly Frankenstein's monster wasn't an option.
Maybe or maybe not. A (relatively) soft plastic casing like that, tends to produce areas that need trimmed away even if you had a conical drill. Might be easiest to just use a brad point drill, and the casing put in the freezer before hand to decrease plastic softness. It may still need cleanup afterwards unless you aren't picky.
The biggest issue I saw with is was you went through all the trouble to install a cooling fan and then restricted the fans ability to take air in by not adding space. Yes, I notice the channel in the cover. But once the blades stall, you basically loose all of your static pressure. You can hear how much more noisy the fan is now that it is on the cover of the battery case. This is indicative of the fan stalling
Do you understand what the word "stall" means, because I don't think that you do? A stalled fan tends to make no noise or at most a ticking sound. Instead, what should be expected is simply a normal result of implementing a fan in a tight space, that turbulence goes up, and of course the RPM drops a bit but this is the point of a fan doing useful work anyway. Yes a larger gap would potentially result in more airflow, except that the exhaust side/holes are at least as much of an impedance, but let's not be a slave to the fan but rather, realize it is a means to an end and that end is simply that it does not overheat.
Step 1) Don't assume it needs fixed unless it is overheating. Step 2) Don't assume every post on a technically oriented youtube video, is made by someone who understands what they're talking about. ;) Step 3) If it is actually overheating, and knowing that it is NOT the blades stalling, you would increase the air intake and exhaust areas in the chassis. Simply putting spacer/standoffs under the casing would be an easy first try, but again, do nothing until there is evidence that it is overheating. @@edumaker-alexgibson
Be interested to see if you get much issue from the gases released from the battery inside the house. It's also explosive. Cars with batteries in the cab have vent pipes attached to the battery to push gas outside cab.
it'd take damn near a dead short to really produce a noticeable amount of hydrogen. cars have vent tubes cause it's a relatively much smaller space and potentially little or no outside ventilation at time, and accidents or malfunctions. if it's in a closet or something, maybe. but any load that would create a noticeable amount of hydrogen gas would blow that 20 amp fuse. i mean, it had a lead acid battery in the first place... just a little motorcycle battery instead of larger car battery. not an entirely different situation. in a car, you're running lots of 20 amp fused circuits at once, averaged from 3, 5, 10, 15, 25amp, etc. this is just one. i don't really know how these work exactly, but i doubt the battery is constantly being cycled like in a car. the only time it comes into use is when there's a loss of power, pretty sure. or it would get a little charge when it goes low.
Have an Eaton true sine wave line interactive UPS, not a cheap unit. I added a T connector to the line between the internal batteries and the inverter. This connector is available to plug in an additional 24 volt 200 amp hour battery which uses the same type of battery’s as in the UPS but larger. My main concern is the algorithm used in inverters to determine how long they will run. I have no idea if they monitor load current as well as battery voltage to determine when to shut down. I use this UPS to feed power to a wood burning fireplace / boiler used for heating my home. It’s main purpose is to power a circulation pump to provide hot water to all of the radiators. If there is no power to the pump or fireplace, the control on the fireplace which has its own battery back up will shut off the air supply to the burn chamber snuffing out the fire slowly to prevent overheating the water jacket and blowing off all the water out of the safety. Currently the UPS will provide 110 minutes of run time utilizing a pair of 12volt 8amp batteries in series on a load of about 150 watts. Will try to figure out with 50 amps available how long it will run.
That's a cool project, and makes sense that the boiler would have a failsafe to prevent overheating if the pump stops. My parents have a sine inverter and a pair of Group 27 batteries like mine that they use to run the pump on their gas boiler plus lights and router if the power goes out. How your inverter behaves depends on that specific brand and model; it may be similar to my cheaper one which will run until the batteries discharge as long as it doesn't overheat or overload. Mine appears to idle indefinitely at no load as well. If your UPS has a built in cooling fan, you're probably safe to let it run for as long as the batteries will last. I'd advise installing a fuse right at the external battery terminal as I did. I'd love to hear back what you find in your experiments!
I am always amazed by people that don't realize that UPS systems have a lead acid battery that will (not may) go bad after several years. As for what to do with them - use them. I have all of my home networking equipment, tvs, and even a few fans that we use at night for white noise hooked to UPSs. I also have a home standby generator, but that takes up to 60 seconds to start carrying load. Plus, we get lots of nuisance blinks. Now, I don't care.
If all you need to power from UPS is computers (either full size or laptops), then there is an option which bypasses all the complicated electronics in a typical UPS: All computer power supplies, laptop charging bricks and flat-panel monitor power supply boards today use lightweight switched-mode power supply circuits to convert mains AC to the low voltage DC the computers actually run on. In all SMPS circuits, the first component the incoming mains AC is routed to after the input socket and switch is a bridge rectifier, which converts the mains AC into DC at more or less the same voltage. Also, pretty much every SMPS circuit built within the last 15 years or so can run from a fairly wide voltage range, usually anywhere between 100 and 250 volts - this is so the manufacturers can use the same circuit for every country which has mains AC power. So it doesn't matter whether you give the SMPS pure sine wave, modified sine wave or even square wave. The AC frequency makes no difference either - it can use European 50 Hz, American 60 Hz, or even in theory the 400 Hz used on airliners. You can see where this is going of course: Since the mains power goes directly into a bridge rectifier first, it also makes no difference to the SMPS whether it gets AC or DC, as long as the voltage is within that 100 to 250 volts range. So if you can get a load of cheap old car batteries from a breakers yard, all you should need to do is wire 10 of them in series and connect the resulting DC voltage to the computer power supply - which would be somewhere between 110 and 145 volts depending on the state of charge of the batteries. Then just have some kind of automatic change-over relay to make the battery bank kick in the moment mains power is lost. This should be entirely feasible - after all, landline telephone exchanges have a similar battery backup system (albeit at 48 volts) which is how your landline phones and landline-based internet service providers still work during power cuts. The same system would also work for many other domestic appliances - LED lights use tiny little SMPS units built into their bases, so they can work from DC. Any resistive heater would also be fine, as would anything driven by universal motors - these have always been able to work from either AC or DC
Very interesting that you brought that up, since I do have some ideas brewing along a similar line for a future project, and I did some experiments with a small fluorescent tube running on DC several years ago. One challenge is appropriate battery management and safety measures because of the unique fault behavior of high power DC supplies. ElectroBOOM has an impressive demo with 10 batteries in series producing brilliant arcs which simply don't happen with AC supplies of similar voltage and current. Another challenge which would need further testing is possible overload on the input rectifier, as components are sized to only conduct for half the AC cycle at a time while the other pair sit idle. Depending on the device this could be entirely a non issue or lead to input stage failure.
@@MetaphysicalEngineerIt's certainly true that DC arcs behave very differently to AC arcs, so that would be a safety consideration. Having said that, some arc-welding machines use AC, so it is still possible to make arcs with AC. Anyway, you can get circuit breakers designed specifically to handle high voltage and high current DC. The video linked below is an extreme example of a DC circuit breaker, likely from a World War 2 submarine, since they used huge banks of lead-acid batteries to drive their electric propulsion while submerged: th-cam.com/video/WAhq_A4EbkE/w-d-xo.html You wouldn't need anything that big though - modern DC circuit breakers are still made, some designed for boats and RVs which have DC power systems, and higher voltage versions for industrial electromagnets which run on several hundred volts DC. You might even be able to use the type of solenoid relays used for switching car starter motors on and off, since those are designed to handle DC at hundreds of amps. So safe battery management for 120 volts DC is certainly possible. Overloading the input bridge rectifier on a SMPS is a possibility for the reason you mentioned, since running DC through them would send the power through only 2 out of the 4 diodes. There are a couple of ways to mitigate that though: (1). If you were only ever going to run the computers directly from a 120 volt DC UPS the way I described previously, all the bridge rectifier would actually do is ensure that the SMPS circuit received the correct polarity (one of the uses for a bridge rectifier is as reverse polarity protection). So provided you ensured that the SMPS was getting DC at the correct polarity and within its working voltage range, it wouldn't actually need a bridge rectifier at all, so you could just remove or bypass it. (2). If you still wanted to keep the option of running the computers from mains AC but wanted to also ensure that the bridge rectifiers in the SMPS units didn't get overloaded, you could always change them out for beefier versions rated for higher current. They are not that expensive, and they are also fairly easy to find on the circuit boards inside the SMPS units. So de-soldering an existing one and replacing it with a bigger one would be fairly straightforward, and this would not affect the operation of the rest of the SMPS circuits.
Nice work. Personally I'd have mounted the UPS on some riser blocks to give the fan a bit more space, but that said, it's still a very neat package. I used to be in IT, and we'd frequently remove and scrap large server UPS units. Companies tend to have service contracts in place that includes checking and servicing their UPS units, and these companies tend to see batteries as consumables, so the batteries in many of the unit's we scrapped were less than 12 months old. It felt like a waste to let perfectly usable batteries go for recycling, so I managed to persuade my boss to let me scrounge a fair few 6 to 12 month old NP12-12 batteries for free (My favourite price ! :D). I didn't really have a plan for these batteries, so I just daisy chained them all in parallel on a charger in the garage for about a year, but then one day I decided that if I didn't do anything with them it would have been pointless getting them, so I tested them all and matched up 16 batteries that were pretty much identical, then mounted then in groups of 8 in 2 heavy duty plastic toolboxes. I mounted a breaker switch, a voltage gauge and a pair of waterproof XT90 connectors on each box, then wired the batteries up in 4 groups of 2, all in parallel for 12V, and with each group having a fuse. The idea is if one in a pair of batteries goes bad and the other 6 try to rapidly equalise the voltage, it'll blow a fuse and then I only have a faulty battery (and one that's probably been damaged from over discharging) to deal with, rather than 8 damaged batteries. It also means that if a fuse blows it just becomes a 6 battery box until I replace the questionable pair, rather than a completely unusable box. This all get's me a total of 194Ah (2,304Wh) of capacity, but due to lead acid based batteries not being particularly happy about being run flat, I've set a much more battery life friendly 96Ah (1,152Wh) output limit for the pair. Because the batteries were free it turned this little project into a ridiculously cheap emergency power solution. These boxes now sit next to my desk, permanently connected to a 20A storage charger. Sitting on top of that is a 3rd identical toolbox which contains 2x 700w (1500w peak surge) 12v inverters, a 300w (600w surge) inverter, several XT90 to XT90 cables, various adapter cables to take XT90 's to things like XT60's, barrel jacks, battery clips, 12v car accessory plugs, and USB chargers, a couple of cheap inline "RC hobby" type volt meters that also log total amp usage, a plug in mains power meter........... And a horrendously power hungry 12v travel kettle (What? I'm not letting a power outage mean I can't drink coffee, am I !!!! :D). There's also a 12v soldering iron wired to an XT90, a selection of bare plugs, a couple meters of a few different gauges of wire, and a roll of solder, all in case I suddenly realise I need some adapter cable I hadn't thought of after the lights go out. :D I've already got a 1600w UPS on my main PC (I've upgraded the battery setup on that. It had 3x NP7-12's in series for 36v, so they came out and it now sits on a case extension that houses a 3P3S configuration of NP12-12's. While doing that I also noticed that mine had a couple of unpopulated spaces for 2 pin fan headers, so I soldered on some sockets that I salvaged from an old motherboard and, hey presto, they just worked. So...... Bonus !), this means the toolbox battery packs are really just to run anything else I want to use in a power outage. If power looks like it's going to be out for several hours I can drag these down to the kitchen to run the fridge and chest freezer for about a day, run the modem and wireless router pretty much indefinitely to get internet access back (Here in the UK, phone lines HAVE to be powered independently, so things have to be getting REALLY SERIOUS before the phones don't work, and according to a mate who works for the UK's main phone company, that includes any data that flows through those phone lines), or just run the modem, and a TV so I can sit back and watch Netflix for significantly more than a day while waiting for the lights to come back on. :D
Fan has more clearance than first appears; compare position of fan intake and the velcro at 27:46 and position of velco and the channel in the battery box lid in the side view at 30:15. That's one heck of a setup you got! Definitely the way to go if you can't let something as minor as a blackout get in the way of your work, leisure, or hot beverage of choice. Unfortunately I have more limited access to scrap items now, between a change in jobs and increasingly strict rules against scavenging at recycling areas. I have yet to see if the network stays up during an outage. I have a suspicion it may also go out since there's an outage notification soon after the blackout begins, and cell service noticeably degrades as well.
A fully charged battery is a happy battery. At 13.8 volts, the UPS is providing float charge for a gel-cell battery. This will not satisfy the AGM. If you want long life (up to ten years), I would disconnect the battery from the UPS and connect an automatic (smart) charger with AGM charge parameter selection - about once a month. OR, at least after any significant discharge time. 13.8 volts will never fully charge the battery. nice project, thanks for the video!
Thanks for sharing your wisdom! That's essentially my plan to exercise the battery now and then. Based on historical data, I'm expecting at least one power outage per month on average. The UPS will take weeks to recharge on its own, so I'll use my external charger to boost it back up afterwards.
The UPS came with an AGM battery. the float voltage is probably at 14.5. This will cook a FLA battery. I'm speaking from experience here. Built one of these a while back and it just cooked the batteries dry due to the 14.5 float voltage. It needs to be somewhere around 13.5 for FLA batteries.
Could you not connect a standard 12v car battery charger to one of the outputs on the UPS to keep the battery charged? Or does it need to go through the internal circuitry?
i also did something like this. got a few ups that where throw out. i got a 60AH lithium battery with it's own bms. ran some wires out from the 600VA ups. works well for 12 hours for my nas. only catch is it take day plus to charge up again, which was expected as lead charges at 0.7A
Cool to hear another success story! Be thankful yours charges in a day; if my rig gets drained significantly, full charge would take days to over a week. I'll have to connect an external charger if I want to boost it back up faster.
I realized too late that I had a lot of holes to drill and my deburring tool was nowhere to be found! I've since gotten a replacement and will be sure to have better finishing tools if I ever need to punch a ton of holes in an enclosure.
Very cool, man. Thank you for posting this. It reminds me to perhaps do better with what I was supposed to have learned in my BSEE degree (read: they taught it, I just didn't try hard enough and it's been years).
A lot of my hands on skills I learned as I went. The best time to start was years ago; the second best time is now. It's only too late when you're gone, so if you're interested, there's never been more resources available for inspiration and learning.
Nice. I personally use an old APC SmartUPS 1500 to cover my router, wifi kit, TV, and a LED light in our living room. I use a large old car battery which is in a vented garden box just outside on our patio. We have lots of powercuts which is why i did this. Its enough to run the LED light and our internet kit for 4 hours. Plus the expensive TV is protected against spikes from the outages.
Interesting project. I'm pretty sure that your APC unit is PWM sine (crappy wave). I chose a small true sine wave (BSINE600 from Tripplite) inverter instead. The SLA batteries in these units are good for one or two shots at high load before they go bad, so i just left the original blade connectors for connecting the SLA battery and made an adapter to an XD90 connector. Then made an XD90 to lug connector adapter cable and hooked up one of the cheap 50AH LFP batteries (probably cheaper than your group 34 deep cycle lead acid battery) which only weighs about 9 pounds. The 13.5 VDC charging voltage from the Tripplite charges the LFP battery to about 96% of it's total capacity, which works great. I have been using this one for over 2 years now and it keeps the internet router up for almost a day, or my laptop and the router going for about 10 hours or so. Hopefully more people will be inspired by your video to "ditch the SLA" boat anchors that come with the vast majority UPS systems today and have a UPS that actually will run a higher load for several hours all while doing it yourself!
Very interesting! For a future upgrade or repeat of this project I'll look into alternate batteries, though I personally don't trust lithium chemistry batteries unless on a dedicated charge controller designed for such. Building a charger mod would be an fun project! You're right that even a relatively inexpensive UPS could deliver much better performance with a lithium, though from my quick estimates, that would double the retail price of a smaller unit such as mine.
@@MetaphysicalEngineer LiFePo4 would be fine there, with the stated max voltage and a BMS (which the mentioned packs include), and perhaps even safer than a marine lead acid battery. Now, lithium NMC (typically known as Li-ion) would not be quite as safe.
nice engineering , but the max 200 watts isnt enough power and board/mosfet will eventually fail ..... better and easy to buy 1500-2000 watt inverter amazon etc $130 bucks and run 1 lithium 100amph and 2 decent size lead marine batteries mixed --(yes together) they work great together, compliment each other and many boat guys do it , then you have mucho power .
Nice to know something I did WAY WAY back in 2000 is being done today. People thought you would Burn your house down doing this. APC makes SOLID GEAR! In fact if you have a tired automotive AGM car Battery? I have used an old APC unit to "Charge it" (REfresh it) to bring it back to life from sulfation. If you ever want to test if a battery can really pass a load test on the cheap? Pick up one of these UPS units. I like the Cyber Powers as they have a display. But the APC units are built old school & SOLID. There is a 24 Volt unit that has a fan built in that needs to be replaced after a few years, but is a great unit to use with large and CHEAP standard automotive batteries. You don't even NEED Deep cycle batteries. You tend to barely use the deep cycling feature, so if it saves you money? Get the cheapest walmart battery you can get and enjoy.
Very cool that you had success with this type of mod in the past! Interesting that your APC unit had a desulfation cycle. I'll have to monitor the voltage to see if mine has anything of the sort. Agreed that the internal parts are more robust than I thought; I went in expecting a struggle to keep the components from burning up under sustained load. This isn't a Walmart battery, but similar in price. Was actually slightly cheaper than the starting battery of similar size. As for the deep cycle properties, depending on what I'm in the middle of, I may actually drain a significant portion of the battery if I have a deadline to meet when the power goes out.
I've heard that since Schneider bought APC (Feb. 2007), the quality of APC UPSs has decreased, but I don't know whether that is true. Cyber Power is a different company, a competitor of APC.
lead acid outgassing does not only happen with higher charge rates and float voltages. give that wet battery a good discharge and then put your ear to it while it's charging and you'll hear it bubbling away. you did so good with the rest of the safety aspects of the project, should add a vent line to outdoors or switch to a big SLA.
LA batteries are placed carefully in cars to account for the corrosion produced in exposed metal near gassing batteries. On my Toyota Van the battery was in a side compartment exposed to moving air and even so isolated, still rusted the sheet metal around it. Mind you, in 5 years on a new car maybe not an issue. My van was 20 yrs old. I can only imagine what it does to electronics like the UPS.
Meh, no, I have listened to flooded lead acid batteries charging all the time, specifically to listen for the bubbling and they usually don't at a reasonable charge rate, until fully charged. This is further demonstrated by plenty of flooded cell batteries in real world applications with constant float charging that do not end up dry after a few years.
Thanks for the tip! Didn't think to try the oscillating saw. I'd worry it would bind up in the melted plastic and simply vibrate the workpiece instead of cutting, but I'll give that a shot next time.
Our cable modem is in the garage. My backup solution for it is a little Eco Flow River 2 power station, clip clip the power cord for the cable modem and run 12V from the power station directly to the cable modem (since it takes 12VDC on its input). By leaving the AC inverter turned off the power station can run the cable modem for 3 days easy on its own during a power failure. Generally speaking, these UPS solutions are built into a lot of power stations these days so even for running AC devices it is pretty trivial, and you get a lot more backup time with a power station than you do with an APC UPS. -Matt
Skipping the conversion is a smart move if the devices allow it such as your modem, and those Eco Flow units have impressive specs! Something I'd look at for adding additional backup power in the future that I can also easily take with me, though two things give me pause for my current application at my workstation: Published switchover time could be fairly long at "less than 30ms", since typical UPS promises a tighter range of 8 to 12ms. My PC would likely drop out if under load since ATX spec is hold up time of 16ms. Also, the 256Wh capacity is extremely good in such a small package but only 1/3 of the capacity of my homebrew setup. I'd need one of the Pro versions at more than twice the cost to have comparable capacity.
@@MetaphysicalEngineer Yes, but you are using a marine battery in what is potentially a home environment, and you are trying to maintain it with the charger controller from a UPS which is designed only for SLA batteries (which can take more of a beating to be frank). Outside of SLA, lead-acid batteries need to be well ventilated. The failure mode for lead-acid is also a big problem. Even UPSs have a hard time detecting that a battery has failed... usually you don't realize it has failed until you actually have a power failure and your "UPS" drops out after only a fraction of the time it was supposed to last. So while it kinda works, it isn't really a robust solution. There are better ways to go. The direct DC solution works for most small devices and will run those devices 2x to 3x longer from the same storage capacity. A LiFePO4 battery, a float-capable charger, and the device (for 12V), and throw in a 12V-to-5V dc-to-dc converter if the device runs off of 5V (the voltage is marked on the devices. 95% of devices these days run off of 5V or 12V). That is a solution that will last 15+ years hands-free. Not even needing a power station. Power stations are pretty good solutions unto themselves, and one can expand the capacity simply by fronting the power station with a 12V battery that you plug into the power station's "solar" input. Again LiFePO4 is the best solution (for the power station and the expansion battery), and one does need a way to charge the expansion battery. Another "expansion" solution for a small power station is USB-C. Some power stations can charge from USB-C, which means you can just connect a power pack with a USB-C output (uni directional) to the power station's USB-C input to expand its effective battery capacity. At least as long as the power-pack doesn't timeout and turn off its output. Wall -> powerpack -> powerstation -> device. Like that. But yes, most power stations have poor AC inverter "UPS" switch times... usually 20ms to 30ms when you really want 10ms-16ms. The absolute best case is 8ms (half cycle 0-current crossing on the AC waveform). Commercial UPSs can do 0ms by leaving their inverters energized and synchronized to the mains. -Matt
i love that model and general design of UPS from APC. they use the SLA batteries that should be replaced about every 3 to 5 years depending on how bad your power system is (the utility). my goes down completely about 20 times a year and i have to replace the SLAs i use about every 3 years. the APC ones are by FAR the easiest to service. takes about 5 minutes. it actually takes way longer to source the replacement because you need to make sure its the right dimensions and tab size lol. pro tip, don't stockpile SLAs if you can avoid it. they have a shelf life and its the same shelf life of 3 to 5 years, even on a trickle charger
Great, clean job. Love your attention to details. Properly done cabling and connectors goes a long way. My only (small) concern is small distance between box top cover and UPS leaving rather small space for air inflow for fan. Probably it's sufficient but I'd add some more distance, perhaps a piece of plastic, like a short pipe or a piece of cable tray or sth like this. Not sure it's needed, perhaps it's just my habits :) Anyway, great job!
Very nice repurposeIng of old UPS. Well thought out and implemented. I am now keeping my eyes open at rummage sales, 2nd hand stores, and Goodwill for a used UPS. I was concerning building one of the solar generators as seen on TH-cam. I want something to take camping or use in an emergency. But your project got me thinking about merging the two, something that I can use as a UPS at home and a solar system that is portable. The way I invision it, I wouldn't need an external charger circuit, or AC power inverter if I start off with the UPS circuits. The thing is, I'm NOT an engineer and don't know how to marry the two projects, and I don't want to do something that has electronic or fire risks. So I'm hoping you might help me by building a project that I can copy. ;-)
Thanks for stopping by! Your idea may actually be simpler than expected! A solar panel with a smart charge controller can feed the same battery as the AC charger in the UPS. All each charger does is interpret the battery conditions and supply carefully regulated voltage and current as needed. When the AC power goes out, the UPS inverter will kick in. As you see when I was testing the unit, simply pressing the power button when the unit is unplugged will also turn the inverter on or off. You are wise to be hesitant about fire risks, hence why I was careful about sizing of fuses due to the huge amounts of energy available from a such a large battery. My main hesitation after that is a UPS is heavy and bulky compared to a typical inverter of comparable power output. Technically portable, but less practical for camping when weight and cargo space are limited. With everything together, my system here weighs in at over 70 lbs (31.8 kg). I can lug it around, but would not want to do so often.
Honestly if you can afford it, I'd recommend something from the Ecoflow River 2 series if you don't feel too confident with what you're doing were you to build your own. Of course what I think is rhe best option is to research until you are confident. And this is coming from someone who built her own full house backup's battery from prismatic cells and an off-the-shelf BMS to connect to a hybrid inverter. If you dislike my recommendation for a ready to go option, there are other brands with useable offerings but i wouldn't trust bluetti in UPS mode for critical loads, my network has already gone offline times enough from such trust.
There are models out there geared toward enterprise applications that have provision for external battery modules. Starting with one of those, much larger custom batteries can be installed like what I did here. Added benefit of high output pro grade units will have internals and cooling rated for extended operation, so no need to hack in a fan.
This is so funny! I have this same exact UPS. I replaced the battery once about 5 years ago, and it recently died again. I bought a new large UPS. This would be a cool project for it!
FYI: if you can find the cable to connect this to USB on your PC and download the software you can adjust the runtime and alarm settings as well as thresholds for triggering a switch to battery power such as the voltage min and max. Typically they default to turning off the power after a few minutes to give the PC time to shutdown and maintain a charge in the battery, I changed mine to run as long as possible regardless of the capacity of the battery.
Interesting that the software has all those options; I'll see if I can get a cable and a version that works since this unit is 13 years old by now. As far as I can tell, this one will run until the battery's drained or an overload occurs.
Nice! I had a bunch of batteries laying around already so I basically did the opposite, picked up a 1kW pure sine inverter and put that before the UPS. Eventually I'll probably make a failover system so it can switch automatically, since I don't have to worry about the switching time due to it being before the main UPS units. Maybe also hook it up to weather so it can precharge before a storm... yay scope creep A week before that however (because of course) I had multiple 24hr+ power outages, and ended up doing pretty much exactly this, but with a power supply powering the UPS off of said random batteries plus a pile of sketchy AF car inverters lol.
Nice job. I have a 20+yr old apc 2200 with an external connector for battery packs. Only downside is it runs from 48VDC & I'd have to drill a hole in the floor down to the garage to add more batteries.
Thanks for stopping by! Understandable that it's a pain to run remote batteries like that. Is putting the UPS down in the garage next to a hypothetical battery bank and pulling a "surge and backup" AC circuit up to your workspace an option? At least for me I'd rather fish romex or armored cable than a set of heavy gauge 48VDC wire...might be cheaper in materials too.
I used UPC similar or just like this for years. Just drilled hole in battery cover and ran right to car battery. Never had any problems if I only connected it to computer and monitor. Much larger UPC units are available for cheap or free that just need a battery. No mods required. I only use semi-sealed batteries (tops don't come off) for less gassing. And I only use APC brand UPC. Less likely to have problems.
I did this with a couple of them. I removed the battery and put in a PC fan and a small 120-12v PSU for it. I ran it off the inverter outlet rails. I broke out the wall between the battery compartment and electronics area. These are underrated to have passive cooling. With forced cooling they do so much more. I also partially bypassed the amp limiter.
Another success story of a hotrodded UPS! 120V to 12V converter was an option I thought about for the fan, but just didn't make as much sense to me since the unit already had a 12V source right from the battery. How much more capacity were you able to get with the current limiter bypassed? I imagine at some point it just bogs down too much or the transistors give up regardless of cooling.
Cool. Will probably do something similar. Use a big rack ups next to my desk. I put a pwm fan controller to turn down the volume and keep it running all the time.
I did one similar a few months ago, I just rectified the drains of the main mosfets and that gave me 12V for the fan. Mine is non-isolated (FSP), so a solid battery box was required, but the low loss and ~70W load it feeds gives me excellent runtime on 50Ah. Enough fuses were added.
I did a similar project for my network. I used an APC UPS from a Walmart Self-Checkout and it ended up having a pretty efficient switch mode power supply instead of the huge 50% - 70% efficiency transformer that most of these use.
Interesting that the self checkout uses a different circuit setup more similar to a mobile inverter. What size battery did you use, what load are you running, and what runtime are you able to get?
Its alot easier to use self tapping screws for creating pilot holes in plastic when you have no anchor. It is also a lot safer than doing it with a drill. Get screw and hammer. Hit it with a slight tap in the spot you want (this acts like breaking the glaze on a tile.) Then use you cordless screwdriver to do the rest. Great vid by the way.
You are out of your mind if you think it is safer to the enclosure to be hitting a self tapping screw with a hammer. If you have no concept of drill depth limiting, the last thing you should involve is a hammer, lol.
On the contrary I could MORE easily state the same about your (in-)experience. It's idiotic to hammer self tapping screws into anything, especially thin plastic. Hopefully some day you will learn how to use a drill properly and open up a whole new world of hole making, lol. @@plebius
@@stinkycheese804 I also thought it was obvious when saying pilot hole, you still use a bit in the handheld screwdriver once you create a pilot hole. Hence me saying you haven't done this. Glhf
Hey, thanks for the video. I now have a better understanding of what one is actually buying when one buys an inverter, and why they often *seem* so different from a UPS even though in principle they're doing the same kind of thing. It's all about the waste heat which sorta kinda varies proportionally to the amount of time the thing is on battery mode and the amount of wattage being pulled. I don't have the skill, patience, or tools to build one of these out of the similar UPS I have that also has a dead battery. But it's neat to see how it works.
excellent work next time don't trim strands off the wire not that its a big issue but I stick an "ALL" or a pic in there and widen the aperture to fit the wire as its a crimp anyway it may buy you a bit more where losses are concerned if you are looking for every bit. I often upsize my conductor runs for solar to help with losses.
I really didn't want to trim that much. Somehow none of the places I went to had 3/8 terminals for 8ga wire in stock. Also funny how an automotive or marine ampacity chart said I could use as small as 12 ga at such a short run. Based on how warm the 10 got during testing, 12 would be cooking at sustained load!
@TechReclamation - Cable gauge, or cross-section losses are only significant over some distance when the resistance adds up. Over a distance of maybe 0.2mm between the trimmed strands and the crimp, the losses would be completely insignificant. After all, consider the tiny cross-section of just the stamped steel in the neck area between the crimp and the actual load connection....
I've been known to remove the plastic from a terminal and open it up a bit by splitting the end. Sometimes it's already cut so you only need to separate it, otherwise a Dremmel helps. Then slip some heatshrink over the wire, crimp it or solder it or both and shrink it down.
Indeed, I realized too late just how many holes I was going to drill and that my deburring tool was nowhere to be found. I'll be picking up a step drill next time I'm at the hardware store as well.
I just need to supply a small load (my little web server + modem & router), so I didn't bother with all that stuff. No fan, no battery box. I just spliced a couple of cables with battery clamps on the ends, in place of the original 7A battery, drilled holes in the UPS box for the two wires, and put the UPS on my desk next to a car battery. (If I'd been intending to power a larger load then I'd have added a fan.) One advantage is that I can swap batteries without shutting anything down. Another advantage is that I always have a fully-charged car battery, ready to go, in case I need it. The first time I had a power outage, it worked fine, but the beeper was intolerable. So, after the power came back on, I removed the beeper. The next time I had a power outage, it lasted 6 hours and 40 minutes! My UPS kept my website up the whole time. Nothing ever smelled hot, and the UPS never got warm to the touch. I clipped a multimeter to the battery terminals, and the voltage decreased by a little over 1v over about six hours. I suspect it was near to shutting down by the end.
Sometimes that's all you need to hold out through an outage! I like the concept of hot swapping external batteries as needed. I've not yet found where my unit will cut off based on voltage, but I'm guessing somewhere below 11 volts since it also assumes the battery voltage will sag under load. You may have had even more runtime remaining than you thought.
I’m watching your video on this ups, and get blown away when you bust out the field piece sman Hvac gauges. Now I gotta dig throuh your channel to see why you have EXPENSIVE HVAC tools on your workbench. I have several sets of them in my HVAC service vans.
I used to work in HVAC and refrigeration but got hit with a career-ending back injury earlier this year. Fine now but high risk of repeat if I go back to heavy trades work. Getting forced to take a step back revealed I wasn't where I wanted to be after all. I am considering getting my license at some point, if only for easier access to certain equipment and parts. I've torn down a compressor with valve failure on here, and have a second compressor with a suspected broken crank also waiting for teardown sometime.
@@MetaphysicalEngineer I’m old school, got my licenses at 17 back when all ya had to do was take the tests. Nowadays, all the insurance and work hours experience needed to qualify to even take the tests slows most from getting licensed. Lemme know if ya need any assistance with anything. I put your video on diysolarforum it should post up after Will Prowse reviews it. See if we can get you some exposure for a nicely done video.
you can also use a stepped bit as an impromptu deburring tool. Funny you'd post this. We have similar power issues where I live. I'm already using a 'failed battery' UPS for surge protection and I've contemplated this exact modification. Now I know what I should be checking before I do the work. Thanks!
Yeah, a step bit would have been helpful at multiple stages of this project. Another thing I rarely used (borrowing the boss man's kit when needed) but maybe time for one of my own. A word of caution from another commenter is checking that the battery side is isolated from the line voltage side. Some units use a "line-interactive" type circuit where significant AC voltage can be present at the battery terminals and could give you a nasty shock if you do a USB charger or 12V socket like I did. Measure between battery negative and ground. You're safe if they are tied together, but beware if you get voltage there!
@@MetaphysicalEngineer Wow! I'll definitely check for AC voltage at the battery, It's kind of insane that a USB would be built that way. I lost a battery in my 1948 Willys CJL because the diode pack on the alternator failed and was bleeding AC power into the battery. FWIW, Harbor Freight in the US carries stepped bits for under $25.
Great reuse! There are a lot of these desktop SOHO UPSs' out there and they die all the time. It's important to note that not all car batteries would be safe for this use. This needs a sealed battery to prevent off gassing as that could create an explosion.
Offgassing is extremely small with a single battery at very slow charge. This is an older house not a hermetically sealed bunker or vehicle cabin, so any gasses dissipate quickly. If I had a bank of large flooded batteries under heavy cycling, I would need forced ventilation, hydrogen detectors, and catalytic recombiners.
Good work. A quick note... you absolutely can NOT use a clamp on amp meter to read DC current. Think about it. Only an alternateing current will generate a magnetic field for the clamp to pick up. For DC Amp you must use a calibrated "shunt" (precision high wattage very low ohm resistor). Measure the voltage drop and use ohms law.
You're right that the regular current transformer clamp meters only measure AC. Meanwhile, Hall Effect current sensors can measure either AC or DC. Most manufacturers have at least one model in their lineup with that function. My RadioShack meter uses a Hall sensor, but I didn't notice the glare and foolishly expected the camera to capture what was on the display rather than recording values manually.
Did this a few years back with a spare inverter and some used solar batteries from a friend who was upgrading to lithium. My home datacenter can run for about 24 hours on the batteries if I shut down everything that pulls a lot of power (ie the desktop and PoE switch). Enough to keep the internet going for a while during power outages, which is nice when storms roll through.
That's how to do it! Hence why I keep have one monitor stay running during the transfer and I'd shut that off too if I had to keep things up for a while. My parents have a few batteries and inverters they use to keep things running during storm outages, as it can be a while before they get power back. Storm raging outside while they're happily siting by the gas insert with a lamp and their laptops, all running off the backup batteries. They can even run the central boiler to keep the pipes from freezing if the temps really drop.
Nice! I got a nice free older but high-end UPS (APC Back-UPS XS 1200) of similar design, even with a brand new battery set the previous owner tried changing out. Unfortunately, it appears (reading data from it over APCUPSD with a special USB cable) that it is sensing AC input voltage as being chaotically all over the place (frequently outside the loosest tolerances the firmware will allow to be set) at all times (even when unplugged?), and refusing to switch from battery to line power due to this perceived unstable line voltage. As this sensing appears to take place from a pair of resistor chains from the high-voltage side heading into what I believe is a TS358CS double op-amp amplifying the difference between them (who's other connections are difficult to trace) and thus doesn't contain any components that seem plausible to wear out over time or easy to test, I'm not sure what I can do to fix it, at least not without a schematic to figure out all the other connections going on. Could worn-out electrolytic capacitors be causing the device's power supply to leak enough noise back to where this voltage sensing is going on to interfere with the process? Replacing the through-hole electrolytic capacitors would be a relatively simple matter of ordering similar parts, but if it's not that I have no idea where to start.
I did something similar to this maybe 20 years ago with a HUGE old APC unit that ran 2 12v batteries in parallel. I used a pair of Marine batteries which are better suited to being discharged over a long period of time. It would run my 2000s PC, dual 19" CRT monitors, and network gear for at least a day. Honestly I never was able to run it long enough to run out of power. A bunch of internet "experts" informed me I was going to blow myself up because of the tiny amount of hydrogen released from the batteries during charging. I'm still here.
I have that exact model. I love, though, it needs a battery. I upgraded to a more powerful unit, but I'm still going to replace the old battery in the 550VA
it's cooling fan, for cooling when it gets too hot? so at, 6:51 the fan running all the time when it unplugged, that the wrong problem/logic you are trying to solve? the correct solution if the UPS gets to hot, and it would not matter if it was plugged in or not its getting to hot? so, it the such a thing as thermal trip, like the ones you get hot water kettle, boil dry, detector not that world work works by switching on power instead of powering off, and at a more desired lower temp. cut on instead cut out?
Original UPS did not have a fan or logic to control a fan. I built the fan control circuit so the fan only runs when the UPS is powering something using the battery and inverter. A mechanical thermal trip like for a kettle safety switch was an option I thought about, but difficult to detect the temperature of components most in danger of overheating (MOSFET and inside the transformer). Electronic temperature sensors would be a more complex circuit. I already planned to add a volume knob to the alarm buzzer, so I used the alarm signal to control the fan as well because the alarm only turns on when the inverter is running.
Great video.. 2 years ago I got given a apc750va unit for free from work ..I've added better heatsinking and a cooling fan and it runs from 3 car batteries recharged from 2x120w solar panels... Runs my workshop networking gear and pc for hours ... I've never managed to run the batteries out before the mains power has come back on ...but it's in excess of 3 hrs .... Also allows me to recharge laptops and power tools 'offgrid' I also have some 3kw 48v tripp-lite units waiting for when I can get some cheap car batteries...those things are built like tanks.
Very cool! Awesome to hear about so many people building super UPS systems. Sounds like you know what you're doing but obligatory caution about how spicy that much battery power can get, the need for matching battery capacity in a series string, and the need for ventilation. One battery on float charge doesn't offgas much, but if you have a rack of standard car batteries on a much faster charger, you'll get more hydrogen.
I used one of these that I had laying around and replaced the internal battery with an 18 amp hour battery. it takes a long time to recharge, but it does work. I didn’t need a fan because I’m using it to run a router that only draws about 10 W. it keeps my Internet up for 12+ hours when the power goes out.
Nice! Sometimes internet and a way to charge your phone is all you need during an outage. May parents do a similar thing with a big battery and inverter since their area is prone to outages in winter storms and low on the priority list for getting hooked back up.
Very well done. Thank you for sharing your work; a device like this is attractive for keeping a photo printer running long enough to finish a job. A company called Noga makes excellent tools for deburring holes, if you're inclined.
Thanks for commenting! Yes this would also be great for printers and similar where a power cut could ruin the batch and waste material and time. Doubly important if there's a deadline to meet. Since I recorded this video, I finally gave up on finding my MIA deburring tool and acquired a new one.
i run an RS1500 with 2 deep cycle battery's keeps my 2 TrueNas and router going for a safe shut down. but all so keeps my WiFi and an energy light going for a day
That's how to do it! It's really cool seeing how many other people have successfully done this type of modification. Video work is only a small part of my job, but the disruption of a power outage alone and sunset happening at 5pm now drove me to do this project.
Thanks for stopping by! These units are great for small loads right out of the box, but most use cases aren't expecting to run at full power for extended amounts of time like I needed here. My parents don't have a UPS but do have some big batteries and inverters to keep their equipment running. A couple years back my dad texted me a pic of him and my mom and the cats watching TV like nothing was wrong despite a snowstorm knocking out power all day.
@@MetaphysicalEngineer I work on film set, Have rack mounted UPS for my Work PC/networking on a cart for and a Powerstation for when 45min on UPS is not enough.
Oi. Your fingers sent a message: please stop lining us up with the dremel cutting wheel (vice, jig, something that doesn't bleed and scream in case of accidents). Always good to see someone else do something to stick it to the UPS oligopolies.
I collect these from people throwing them out. I just order new batteries. First thing I do is clip the beeper on the board. I do get good used batteries from a buddy who changes out batteries on emergency lighting fixtures inn commercial buildings.some places change them out yearly.
Sir, I was an electrical engineer in the 1990's when I was in the Air Force. I absolutely loved watching this! What a great idea! How much did everything end up costing you? I've only just found your channel, but you definitely earned my SUB with this one, brother. I look forward to reading all the FAQ's below (I knew the Karen's would be screaming about off-gassing, LOL)! Anyway, looking forward to binge-watching some of your other videos. Shalom
Thanks for your kind words, and thank you for your service. The total was around $200, since I got the original UPS for free and added the accessories to the battery box myself instead of spending $100 or more on a prebuilt one.
Had one of thse where a small amount of liquid got into the inverter side plugs.Popped it open dried the liquids up and for good mesure tightend the loose metal of the plug contatcs.
I tried this once, but gave up immediately once I learned the UPS I was using had a history of short circuit and fire risk issues. Fun project, but I'm not looking to burn the house down. Can't remember what I used for the fan turn on signal though, but I know it involved making a NOT gate from a few transistors.
When you build a UPS like this without an SLA, then you need to add provisions for a failure mode where the BMS fails on and cooks the battery. this means you just have some sort of tray under the battery that you put something like baking powder in to neutralize any boiling acid that escapes the battery. You can simply just pour some baking powder into the battery box itself, which is what a lot of off the shelf solutions do. you just want enough powder such that you have an excess required to neutralize all of the acid inside the battery (its like a few cups or something). And then you also want to have ventilation of some kind. any kind of passive venting like just a door that is open or a cracked window or even just a return vent to a central HVAC will work fine. This is to prevent hydrogen build up in the case of a BMS failure where the battery boils but it will also eliminate any possibility of hydrogen build up. With one battery though, hydrogen build up is i think impossible, at least you will never get enough to have a reaction. even if you had open sparks above the battery at all times, a single battery like this probably can't make enough H2. So i would just make sure its not in a confined space like sealed into a concrete bunker room with a sealed door. You only need H2 and active venting when you get up to like 10 of those batteries or so. You also want a jug of unopened distilled or deionized water next to your UPS. i recommend having a 1 gallon jug because you can get them anywhere and they are super cheap. just get one and stick it next to the UPS. you will thank me in 15 years when you realize the battery is low on acid and you can just grab the jug to top it off. for a large set up with numerous batteries you want to use the actual acid, but for just one you can get away with using water. in my experience it takes something like 10 years for the voltage to start to drop from lower acid levels and you just need to add the distilled water to get the electrodes inside covered again. or you can always just let it rip and not do any of that. really, worst case is the BMS fails on and boils your battery, the caps pop open, sulfuric acid boils and splashes out and leaks down the sides, and ruins the subfloor. worst case, you end up replacing like a two foot square chunk of carpet and subfloor. ask how i know hahaha
Adding baking soda to the bottom of the battery box is a great idea! Like the battery spill kits we kept on hand back when I coached robotics clubs. Though I imagine the battery charger will likely fail open circuit rather than full on. Other commenters have mentioned the charge circuit giving up. This 1960s building is leaky and the HVAC cycles enough that buildup of gasses isn't a big concern for me. I think I'd need more batteries and a tightly sealed room before enough hydrogen could accumulate to be a danger. In that case I'd have AGM or LiFePo4 or rig up catalytic recombiners that intercept the offgassing and return the water to the cells, like what's used on large scale battery banks with flooded cells. I have a jug of distilled water on hand already, and I'm planning on a quarterly or so test and inspection. My parents do that with their backup batteries now, after making the mistake of leaving them be and getting caught with crippled backup power one winter. Thanks for the cautionary tale about the acid spill eating the floor. I hope I never encounter that issue!
More projects will be in the works for sure! Though given my range of interests and duties, a wide variety of hacks and repairs and more will also appear.
You could hang a small solar panel outside a window and use that to power the device while in standby mode. That should be enough to keep the battery charged. You would only need mains power if an actual load is connected.
That's a viable option since this side of the house gets plenty of sun. I'll borrow the little 18W smart solar battery maintainer from my car to see how that behaves. Anything would be faster than the tiny 3W charger in the UPS, though I fully expect to need an external mains charger to recover from an outage in reasonable time.
@@MetaphysicalEngineer That is the idea. Use mains for recharge, but solar for standby. with a bit of luck, it will give you enough power to charge your mobile devices for free. Not only will that save you some money, but you will have some power even in case of a prolonged outage.
Another success story! Thanks for weighing in! Where and how did you mount your thermal switches on your unit? I was concerned about the vastly different thermal behavior of transistors and transformer, and difficulty of measuring the hotspots.
@@MetaphysicalEngineer In my APC ES700 transformer is hotter than mosfets under 200-300W load, so I put thermal switch between housing and transformer core and fixed it with some heat-resistant glue. Made it about year ago, not sure about small details but overall concept is exact. Any thermal resistance between windings and core I've compensated using lower temperature switch, somewhere around 50C. The only negative side I've found since modification is fans work few minutes more than required after UPS switches to AC. However, during my experiments inner windings were about 20C hotter than outer, so it's pretty safe.
@@HeIsTheHighlander, can you please be specific about what thermal switch you used, and where you got it? (Don't specify a URL, because youtube will block your comment if you do.)
KSD-01F - first results via search "thermal switch to 220" with no quotes on Ali. Normally open for fan, meaning it will close reaching target temperature. They're made on different temperatures.
@@ncdave4life I've bought them both type (NC and NO) and almost every temperature, it was cheap include shipping to Russia, I think cheaper than $1 each. Not sure about exact numbers, it was a couple years ago. I think they should work in parallel, but in my case transformer was hotter than mosfets, so I used only one thermal switch.
I did this back in about 1999 to several of my UPS's. I used lawn tractor batteries from Walmart. 20 bucks. Too bad they are much more expensive now. One of my UPS's was a sine wave type that was very expensive and also highly inefficient so it was already equipped with two lead acid batteries. But they had reached their end of life so the company junked it and it became mine. I put two used but still functional car batteries on it. It could hold up my computer for several hours. BEWARE: Most UPS's put out a pseudo sine wave which is sort of a square wave. The problem is the edges of that square produce lots of high frequencies.(See Fourier transform theory.) If that voltage is applied to an iron core transformer like the old wall wart kind(all we had in 1999) that weren't using a switching circuit, then the high frequency eddy currents in the iron core will heat it up to the point that the safety heat fuse opens and the wall wart is dead. Those old wall warts can take that pseudo square wave for 10 or 20 minutes but much longer than that and it's curtains. The newer light weight switching kind are fine with that square wave. And you know what I did don't you? I cracked open that wall wart and jumpered that safety heat fuse and it was back working. I left the plastic case off and always had it in a place where it got plenty of air to cool it off. Safety third.
I did this with a ES-350 and an 100ah battery to back up my pellet stove and it worked ok without a fan but the internal charger could not bring the battery back up so I had to add a 5A charger. I also just put hot glue in the buzzer to mute it. I've since moved to a 1200VA ups which has a built in fan and it's able to maintain the 100ah battery on it's own (so far).
The charger is a weak point on these units when the battery is upgraded; other commenters have mentioned the chargers failing. Agreed a bigger UPS would have been a better starting point since the cooling and charger would be better suited to the use case I wanted. If mine goes out, I'll rig a more powerful smart charger to the unit. As of now I need to manually hook up a charger to make sure the battery recovers fully after significant use. My parents use a big battery and inverter to run their central boiler through outages. I converted the boiler from hardwired to a standard power cord so it can be plugged in to mains or switched to an inverter. With careful management they can have days of heat, which is long enough for even the worst outages in their area to be resolved.
@@MetaphysicalEngineerabout 350 watts,never found out runtime,it was hours longer than i ever needed,it might still be in my storage unit,if it is i'll get it out and take some photos
It's not clear from the spec sheet how much of an approximation the outut waveform is, but it says stepped approximation to a sine wave. Some equipment doesn't like that. Given the availability of cast-off UPSs, I'd hold out for a UPS with pure sine wave output. I used a Cyber Power 900AVR with two marine batteries when I did this the first time. That one also produces simulated sine wave AC, but also provides automatic voltage regulation for dips and has higher rated output so it should run cooler to begin with.
Stepped approximation means modified sine in this case. Waveform looks like off period, square wave positive, off period, square wave negative, repeat. Easier than square wave with no off period, but certainly rougher on some equipment. My computer PSU explicitly states in an FAQ that the input stage is capable of running on modified sine, but that may not be the case with all brands and models. Wasn't sure the direction this video would go when I started. Could have been a teardown and analysis of a failed unit, replacing a dead battery, failure during the extended load testing, etc. Instead since it proved more robust than expected and how much that most recent blackout bugged me, I turned it into this project as shown. Absolutely have plans for a future version 2 with a much better UPS at its core, possibly with high performance LiFePo4 batteries and hybrid grid-solar charging system. But that's way outside of my budget for the moment.
@@MetaphysicalEngineer LiFePO4 batteries are very cheap right now. Maybe getting cheaper? I just today hooked up a 4-pack of 304AH cells ($90 ea) to a Yeti 1250 to provide some serious capacity. The Yetis are discontinued and sometimes you can get one cheap. They have all the goods inside like pure sine inverter, a couple of different charging inputs with fairly large range of voltage (but limited to around 260W), older USB (1A?) and 12V accessory. I added a real BMS because the Yeti only knows how to handle AGM, plus it doesn's balance. You can run it without, but not recommended. That's one way to get started.
a small analog clock would be a nice, little and cheap addition to the segments you know you'll be fast forwarding :) it's your first video for me, you got a new sub :D
One thing I question: in the final assembly, isn't your intake fan between the UPS chassis and the battery box, with only a thin channel for air intake?
Ah, I should have gotten a better shot from that angle. The fan intake lines up with the channel molded in the battery box lid and the lift from the dual lock velcro pads securing the UPS added even more clearance. Plenty of airflow! You can get a rough idea by looking at where I placed the pads on the UPS around 27:45 and where the pad is visible just above the switch on the assembled product around 30:14.
I've actually done this to the ups that's powering my PC at home, though I didn't open up my ups. I just installed to parallel lawn tractor battery's on it. Though I've thought about using a generator hooked up to the DC side incase of long term use. Maybe solar
If you have a suitable DC generator, that would boost the runtime for sure. These units will likely handle input in the 11 to 15 volt range. Keep an eye on temps, as the internals will just keep heating up until something cooks if allowed to run longer.
I have been looking for a heavy-duty UPS unit for years that could just be hooked up to a large deep cycle battery either lead acid or lithium to run important circuits in my house we get annoying blinks in the power which I'M sure are not good for electronics. the electric company at first when i complained said nothing was wrong then after me calling a few times somebody realized a tree rubbed through the wires at end of block and was shorting them out in wind or rain. Still get some glitches but not as many now.
Battery negative is tied to earth, so a maximum of 13.5V DC above earth at the positive terminal. No risk of shock from the battery terminals as long as the building wiring is correct.
Parts list, per request. Read datasheets and verify before ordering. I take no responsibility for any property damage, injury, etc. arising from attempts to replicate this project. P1 | PTN16-D01115K1B1 | 1k Potentiometer 0.125W Any similar part will work D1 | 1N456ATR | General Purpose Diode 30V 0.5A Any similar part will work Qi | 2N4403TAR | General purpose PNP transistor 40V 0.6A hFE 100 Any similar part will work Qm | IRLZ44NPBF | N-Channel MOSFET 55V 47A Threshold 2V Overkill for this application; any similar part will work C1 | EEU-EB1E101SH | Aluminum Electrolytic Capacitor 100uF 25V Any equivalent part will work R1, R3 | CF14JT1K00 | 1k ohm 0.25W Any equivalent part will work R2 | CF14JT560K | 560k ohm 0.25W Any equivalent part will work
You mean the overlay showing the calculations? Those are found on the APC website. Search the brand and model of the UPS and most will have a tool to estimate run time at various loads. Take with a grain of salt since those assume a new, fully charged battery and perfect operating conditions.
Careful lead acid batteries emit hydrogen. Otherwise solid build. I have done something similar and recommend Bigbattery lithium 12v. They are more expensive but more reliable.
Was wondering when somebody would bring this up. However, at 13.5V float charge and 0.3A max charge current, off gassing is minimal for a battery of this size. If I ever need to fast charge or exercise the battery, I'll ensure there's extra ventilation. Lithium would be an option, as would AGM, with the downside of expense. Perhaps when this battery gets retired, I will upgrade to a safer, higher performance type. Thanks for stopping by!
*Hydrogen? Explosion risk? Why not lithium? Parts list?*
!! FAQ HERE !!
Update video: th-cam.com/video/IPXNGt6NfsU/w-d-xo.html
Stream discussing some of these:
th-cam.com/users/live9JOuYWRu3h4?feature=share
*What about Hydrogen?!* A single battery at float charge has very slow rate of offgassing. If the battery released enough gas to be an issue, it would be dry in weeks, as would every other battery ever connected to a battery maintainer (which defeats the purpose entirely). This is one battery in a 1960s building with significant air exchange, not a bank of batteries under heavy cycling in a hermetically sealed bunker. Yes an AGM would be safer, and is a possible future retrofit.
*Modified sine wave will destroy your computer!* My computer's PSU is rated for use on modified sine, according to the manufacturer on the official FAQ. Not all brands or models give that assurance.
*The battery will spray acid if it suffers a major failure!* Even a sealed or AGM battery will vent under those conditions, though random catastrophic failures are very rare without external causes such as mechanical damage, short circuit, or extreme overcharging.
*What about LiFePo4 / Lithium?* Higher performance but expensive and needs separate battery management; planned for a future version 2 of this project!
*Y'know, there's a thing called a deburring tool instead of a utility knife...* I had one. Discovered it was missing when I went to do that stage of the project and realized just how many holes I had to drill. I have since replaced it. And gotten a step drill bit as well.
*The fan is blocked! There's no airflow!* Fan has more clearance than first appears. Compare position of fan intake and the velcro at 27:46 and position of velcro and the channel in the battery box lid in the side view at 30:15. Almost as if I planned the placement! Not as effective as open air, but still plenty.
*Just buy a huge power bank with built in inverter!* Power banks with UPS functions are neat, but every one I've seen linked so far has abysmally slow transfer time of 30ms, which would guarantee my computer shutting down during the switch. Also, units with comparable runtimes get very pricey, approaching 4x the cost of this project. If you have suggestions, please let me know. At a future point with more budget, I'd consider doing product reviews.
*How long does it take to charge?* It will get there. Eventually. The charger in the UPS is a maintainer more than anything for a battery of this size. Significant discharge will require a boost with external charger. Adding a better charger is another potential future upgrade.
*Why didn't you start with a top of the line high power UPS?* I found this one for free in a scrap pile in the stairwell of an office building. I was either going to analyze why it failed or replace the internal battery. Then got annoyed enough at a power outage to try strapping a car battery to it and seeing what it could do. Results were better than expected, so I turned it into a full project. Of course it's not perfect, but it does do what I asked it to do, and I got a cool video.
*Why keep the alarm buzzer?* I wanted the option to have the alarm. But also an option to turn it down. A latching, auto reset mute circuit would have been a cool alternative where could just press a button to silence the alarm and it would stay off until the next power loss event.
*Ew the music!* Agreed; I could have done better and I'm working to improve future content. If it bothers you that much, nobody is forcing you to watch :)
*Parts list??* Here you go! Read datasheets and verify before ordering. I take no responsibility for any property damage, injury, etc. arising from attempts to replicate this project.
P1 | PTN16-D01115K1B1 | 1k Potentiometer 0.125W Any similar part will work
D1 | 1N456ATR | General Purpose Diode 30V 0.5A Any similar part will work
Qi | 2N4403TAR | General purpose PNP transistor 40V 0.6A hFE 100 Any similar part will work
Qm | IRLZ44NPBF | N-Channel MOSFET 55V 47A Threshold 2V Overkill for this application; any similar part will work
C1 | EEU-EB1E101SH | Aluminum Electrolytic Capacitor 100uF 25V Any equivalent part will work
R1, R3 | CF14JT1K00 | 1k ohm 0.25W Any equivalent part will work
R2 | CF14JT560K | 560k ohm 0.25W Any equivalent part will work
Well fine. You covered everything I had to say in one post.
Nice preemptive for all the self-righteous know-it-alls. I have almost a dozen old school and newer UPSs and have wanted to do this since the first one. Am saving this video for a template to start from.
Just out of curiosity, I'm left wondering how much was spent (hard $ ... not time) on this free UPS. Granted, you ended up with a very beefy UPS.
Nice. We could easily use those "drop in lead replacement" LiFePo4s with the built in BMSs yeah?
I have some spare, and an old rack mount UPS that could be put to good use, although I think it may be 48v and I think my lithium's only handle 2S chaining. Hmmm 🤔
@bc4yt Yes, though I would mod in a dedicated charger circuit when changing battery chemistry and make sure to follow battery manufacturer's application instructions. Integrated BMS can only see what's happening inside that single battery, so could be overwhelmed if a problem happens to another in the chain.
I liked how for every modification step you checked that it would not catch fire.
When the battery can dump nearly a thousand amps into a fault, things get rather exciting. Getting or building a bench supply is on the long list of things to do.
@@MetaphysicalEngineer time to buy a bum desktop computer just to turn the PSU into a bench power supply.
@@MetaphysicalEngineer Agreed. Had a motor driver fail SS and in the few seconds it took me to pull the batteries it desoldered almost every connector and stripped every wire in the chain, and that was likely only ~200A. When the battery can weld a wrench across itself, you take extra precautions 😅
@@Lizlodude Holy cow! Sounds like it got your heart pounding! Glad you're ok!
Was that on a high performance RC vehicle?
Great project. I did this exact same thing a few years back (minus the fan driver circuit). I ran into a problem that you will probably run into as well. The batteries in these UPS devices are AGM (absorbed glass mat) but the boat/car batteries are FLA (flooded lead acid). I had a problem where the float charger in the UPS would basically boil the FLA batteries dry and destroy them. I found out that the charger was trying to overcharge the FLA batteries. The "full" voltage that the float charger in the UPS I had was 14.5 volts due to it using the AGM battery. This is too high for a FLA batteries. They should float about 13.5 volts. I could not find any way to adjust the float voltage in the charge circuity so I gave up on the project, I just went through too many batteries to make it worth it. Another thing I found was that the FLA batteries off-gas quite a bit while they are charging. At first I had the entire setup inside the house, but things in that room started rusting and the I started getting complaints about the smell (the off-gas is also explosive. It's hydrogen gas) so I moved the batteries outside and ran the charge wires through the wall through and existing hole. You might look on your APC board and see if the float voltage is adjustable. Just my opinion and my experiences.
Being more expensive, AGM batteries in a UPS application would be uncommon. Typically you will find sealed gel-cells in the commercial market, which you have to be even gentler with.
Interesting that yours ran the charge voltage so high. 14.5V is very high even for an AGM type; typically I see 13.8V listed for AGM float at 25C. Constant 14.5V will cause significant offgassing, while at 13.5V offgassing is minimal. 30:06 is where I show the final product, including float voltage and testing with my computer as load.
@@MetaphysicalEngineer thanks for the reply. My current Trip-lite has two ES7-12 AGM batteries in it. I just replaced them. It was not an expensive unit, but came with AGM batteries. It’s the Trip-lite model SMART1300LCDT. So there is that. Anyone who is thinking of doing this mod should pay attention to what the charge voltage is for the batteries you are replacing with FLA.
A better choice and longer lasting both in capacity and battery life is going with LiFePO4 batteries.
@@FirstLastOne Yes, but they require an entirely different charge profile.
Always check the contacts on these older UPS units, over the course of years they can start to subtly corrode then heat-up and corrode even further. I had one getting to the point I heard faint arcing, the problem connector was immediately obvious, discolored and pitted metal on the contacts(on the high-current LV side of the transformer interconnect), The wire guage was too big to fit the holes present, so used forked spade terminals to repair it and cut off one side of each spade to use as through-hole, soldered those in, checked thermal camera, and have been good ever since. This is one of the first UPS units I ever bought 15+ years ago and it's still going strong. Each time I've tried to replace it, it keeps outlasting it's replacements.. one lost it's mind and exploded it's push-pull FETs randomly one night, the other started kicking the GFCI at when it performed it's sporadic self tests, never a dull moment.
I'll keep that in mind about failure of those connections, especially if this unit sees significant use. I already plan to do inspections now and then. Nice job bringing your unit back to life, and quite funny how it seems determined to outlast everything else you buy!
8 years ago, I lost the power drop and breaker panel from my small mountain house during a landslide. (As well as many other things!) It took a year and a half to get everything back on the grid. In the meanwhile, I took the 650 model of that UPS, bought 6 golf cart batteries, brought out some heavy leads from the UPS, tied the batteries up with an external 60A charger and ran all the house lighting (LED) cable modem, router, pico cell site and 32" TV/monitor and laptop from it for about 16 months. Charging during the day with a small inverter generator. Worked well for all that time, never an issue. After I was back on the grid, pulled the UPS apart. No signs of heat or component stress whatsoever, still worked great. Maybe pulled 20-30W at night, max maybe 200 during the evening. Carried me well for those several months. Now I've got 20Kwh LFeP04 battery and a 3000W inverter/ups/charger which can handle everything for a few days. (mtn folks lose power a _lot_) But that little APC did great! The transformer based ones are very solid.. Good vid!
Wow that's quite the experience! Glad you were safe! Sounds like these units are quite tough; I wonder what the inside of the transformer windings on your unit looked like as those seemed most likely to be stressed long term.
Wise move to have ample backup power where you live it seems. Hence my frustration that my place here in the suburbs gets such unreliable power when we don't have landslides and ice storms and such.
The transformer had no discoloration of the bobbin plastic at all. Early on, I tried loading it down to almost ratings and checked external temps carefully, seeing almost no rise.
My usual "hi" load would be about 200W, most of the time more like 80-100W. Small 32" LCD TV, laptop, all LED lighting. Modem, router and pico cell. After 16 months + continuous running not even any really hot resistors or anything.
(I've been a tech for (gag) 50+ years now, and always crazy about batteries and power systems.)
Since those days, my loads have increased, 50" TV/monitor, SFF desktop PC (10 years old. Really have to swap in the new Ryzen system, but lazy...) added a Starlink sat setup so that when it really gets ugly up here, power, comms and everything down, I can still communicate. Does draw 60-80W, tho, it seems)
Current base load about 200-250W, more like 500W +refer/freezer for max. (70-80w freezer, cycling, 80w refer compressor cycling/400w defrost cycle)
As of Thursday, all my 'critical' circuits here have been cut over to the SunGold inverter/charger and the 20KWh LiFeP04 setup. Utility has an outage scheduled for all day Wed, will see if the house systems even notice. If I'm frugal, can get around 4 days runtime. Have many hour/multiple day outages at least a few times a year here. Redwood forest, many trees. Refer, freezer and microwave now added to the system. Surplus, quality LiFe batteries are getting to be pretty good deals! Enjoy your little APC!
@@MetaphysicalEngineer
@@MetaphysicalEngineer : The most common cause of power loss is cars running into poles, and then various tree-related maladies.
exactly yep . nice engineering , but the apc max 200 watts isnt enough power and board/mosfet will eventually fail ..... better and easy to buy 1500-2000 watt inverter amazon etc $130 bucks and run 1 lithium 100amph and 2 decent size lead marine batteries mixed --(yes together) they work great together, compliment each other and many boat guys do it , then you have mucho power .
I recommend you pick up a pen-style deburring tool. Cheap and works much better than a file or utility knife for holes. Great video.
Indeed! I looked for mine when I realized how many holes I had to drill and how tough the burrs were, but it wasn't anywhere it should have been, and I haven't used it in a while. Watch me find it tomorrow when I'm searching for something else!
@@MetaphysicalEngineer I always said my shop is infested with Gremlins. They love to hide things. Their neatest trick is hiding the tool I laid down beside me two seconds ago.
@@baldeagle5297My shop floor gobbles up everything that drops on it, disappears for life. Most of all seems to like those screws and nuts that are of the typical nonstandard size.
@@MetaphysicalEngineer The style of deburring tool I have would work reasonably well here as well--I don't know the name for the style of it, but I am thinking it's different from the "pen-style" type referred to by willusher3297. Good for metal and softer, it uses curved/S-shape blades pivoting on an axis in the tip of a plastic handle. It comes with three different blades and you can swap them out: one for steel, aluminum, and plastic, another for brass and cast iron, and another for "...straight edges on almost all materials." Extra blades stored in handle. It's a Blue-Point DEBUR 300, though perhaps multiple companies have made it. That said I finally read your reply after typing the above and see that you have a pen-style or at least a deburring tool already. Ah well. :) Update: I see in another reply that you've already acquired a replacement.
Great upgrade of old hardware! I really appreciate how thorough you are at every step.
A most honestly an 'Engineered' solution to this problem. Step by step what I would do myself, but also being honest, a much more presentable "product" that I would have likely done myself, if for my own use. Currently have a slightly smaller APC that I'm going to perform a similar upgrade to. Thanks for the work!
Good luck on your project, and please don't forget the fuses! Aesthetics were partly for the video, and partly because my lady and I will have to perceive the end product in the bedroom/office, so an ugly Frankenstein's monster wasn't an option.
Conical hole chamfering bits are your friend for cleaning up holes. Muuuuuuch easier than using utility knives.
Definitely getting a chamfering bit if I need to punch that many vent holes again. Thanks for commenting!
Maybe or maybe not. A (relatively) soft plastic casing like that, tends to produce areas that need trimmed away even if you had a conical drill. Might be easiest to just use a brad point drill, and the casing put in the freezer before hand to decrease plastic softness. It may still need cleanup afterwards unless you aren't picky.
@@stinkycheese804 I mean one of those conical reamer bits with a 90°+ point angle to clean up the drilled hole, not a cone or step bit.
The biggest issue I saw with is was you went through all the trouble to install a cooling fan and then restricted the fans ability to take air in by not adding space. Yes, I notice the channel in the cover. But once the blades stall, you basically loose all of your static pressure. You can hear how much more noisy the fan is now that it is on the cover of the battery case. This is indicative of the fan stalling
What would be a good set of steps to fix it in this exact case?
Do you understand what the word "stall" means, because I don't think that you do? A stalled fan tends to make no noise or at most a ticking sound. Instead, what should be expected is simply a normal result of implementing a fan in a tight space, that turbulence goes up, and of course the RPM drops a bit but this is the point of a fan doing useful work anyway.
Yes a larger gap would potentially result in more airflow, except that the exhaust side/holes are at least as much of an impedance, but let's not be a slave to the fan but rather, realize it is a means to an end and that end is simply that it does not overheat.
Step 1) Don't assume it needs fixed unless it is overheating.
Step 2) Don't assume every post on a technically oriented youtube video, is made by someone who understands what they're talking about. ;)
Step 3) If it is actually overheating, and knowing that it is NOT the blades stalling, you would increase the air intake and exhaust areas in the chassis. Simply putting spacer/standoffs under the casing would be an easy first try, but again, do nothing until there is evidence that it is overheating. @@edumaker-alexgibson
Way cool and most definitely a viable solution for longer than 12-20 min battery backup!
Keep em coming!!!!
That's the idea! Thanks for watching!
Be interested to see if you get much issue from the gases released from the battery inside the house. It's also explosive. Cars with batteries in the cab have vent pipes attached to the battery to push gas outside cab.
it'd take damn near a dead short to really produce a noticeable amount of hydrogen. cars have vent tubes cause it's a relatively much smaller space and potentially little or no outside ventilation at time, and accidents or malfunctions. if it's in a closet or something, maybe. but any load that would create a noticeable amount of hydrogen gas would blow that 20 amp fuse. i mean, it had a lead acid battery in the first place... just a little motorcycle battery instead of larger car battery. not an entirely different situation. in a car, you're running lots of 20 amp fused circuits at once, averaged from 3, 5, 10, 15, 25amp, etc. this is just one. i don't really know how these work exactly, but i doubt the battery is constantly being cycled like in a car. the only time it comes into use is when there's a loss of power, pretty sure. or it would get a little charge when it goes low.
yeah this is why you usually get AGM batteries for this sort of thing.
@@kargaroc386 I have never seen a consumer UPS with an AGM. Are they common?
Have an Eaton true sine wave line interactive UPS, not a cheap unit. I added a T connector to the line between the internal batteries and the inverter. This connector is available to plug in an additional 24 volt 200 amp hour battery which uses the same type of battery’s as in the UPS but larger. My main concern is the algorithm used in inverters to determine how long they will run. I have no idea if they monitor load current as well as battery voltage to determine when to shut down. I use this UPS to feed power to a wood burning fireplace / boiler used for heating my home. It’s main purpose is to power a circulation pump to provide hot water to all of the radiators. If there is no power to the pump or fireplace, the control on the fireplace which has its own battery back up will shut off the air supply to the burn chamber snuffing out the fire slowly to prevent overheating the water jacket and blowing off all the water out of the safety. Currently the UPS will provide 110 minutes of run time utilizing a pair of 12volt 8amp batteries in series on a load of about 150 watts. Will try to figure out with 50 amps available how long it will run.
That's a cool project, and makes sense that the boiler would have a failsafe to prevent overheating if the pump stops. My parents have a sine inverter and a pair of Group 27 batteries like mine that they use to run the pump on their gas boiler plus lights and router if the power goes out.
How your inverter behaves depends on that specific brand and model; it may be similar to my cheaper one which will run until the batteries discharge as long as it doesn't overheat or overload. Mine appears to idle indefinitely at no load as well. If your UPS has a built in cooling fan, you're probably safe to let it run for as long as the batteries will last. I'd advise installing a fuse right at the external battery terminal as I did.
I'd love to hear back what you find in your experiments!
Got a pile of UPSs here for recycling, all had bad batteries when I got 'em. I'm going to have to look into seeing what can be done with them... :-)
I am always amazed by people that don't realize that UPS systems have a lead acid battery that will (not may) go bad after several years.
As for what to do with them - use them. I have all of my home networking equipment, tvs, and even a few fans that we use at night for white noise hooked to UPSs. I also have a home standby generator, but that takes up to 60 seconds to start carrying load. Plus, we get lots of nuisance blinks. Now, I don't care.
If all you need to power from UPS is computers (either full size or laptops), then there is an option which bypasses all the complicated electronics in a typical UPS: All computer power supplies, laptop charging bricks and flat-panel monitor power supply boards today use lightweight switched-mode power supply circuits to convert mains AC to the low voltage DC the computers actually run on. In all SMPS circuits, the first component the incoming mains AC is routed to after the input socket and switch is a bridge rectifier, which converts the mains AC into DC at more or less the same voltage. Also, pretty much every SMPS circuit built within the last 15 years or so can run from a fairly wide voltage range, usually anywhere between 100 and 250 volts - this is so the manufacturers can use the same circuit for every country which has mains AC power. So it doesn't matter whether you give the SMPS pure sine wave, modified sine wave or even square wave. The AC frequency makes no difference either - it can use European 50 Hz, American 60 Hz, or even in theory the 400 Hz used on airliners.
You can see where this is going of course: Since the mains power goes directly into a bridge rectifier first, it also makes no difference to the SMPS whether it gets AC or DC, as long as the voltage is within that 100 to 250 volts range. So if you can get a load of cheap old car batteries from a breakers yard, all you should need to do is wire 10 of them in series and connect the resulting DC voltage to the computer power supply - which would be somewhere between 110 and 145 volts depending on the state of charge of the batteries. Then just have some kind of automatic change-over relay to make the battery bank kick in the moment mains power is lost. This should be entirely feasible - after all, landline telephone exchanges have a similar battery backup system (albeit at 48 volts) which is how your landline phones and landline-based internet service providers still work during power cuts.
The same system would also work for many other domestic appliances - LED lights use tiny little SMPS units built into their bases, so they can work from DC. Any resistive heater would also be fine, as would anything driven by universal motors - these have always been able to work from either AC or DC
Very interesting that you brought that up, since I do have some ideas brewing along a similar line for a future project, and I did some experiments with a small fluorescent tube running on DC several years ago.
One challenge is appropriate battery management and safety measures because of the unique fault behavior of high power DC supplies. ElectroBOOM has an impressive demo with 10 batteries in series producing brilliant arcs which simply don't happen with AC supplies of similar voltage and current.
Another challenge which would need further testing is possible overload on the input rectifier, as components are sized to only conduct for half the AC cycle at a time while the other pair sit idle. Depending on the device this could be entirely a non issue or lead to input stage failure.
@@MetaphysicalEngineerIt's certainly true that DC arcs behave very differently to AC arcs, so that would be a safety consideration. Having said that, some arc-welding machines use AC, so it is still possible to make arcs with AC.
Anyway, you can get circuit breakers designed specifically to handle high voltage and high current DC. The video linked below is an extreme example of a DC circuit breaker, likely from a World War 2 submarine, since they used huge banks of lead-acid batteries to drive their electric propulsion while submerged:
th-cam.com/video/WAhq_A4EbkE/w-d-xo.html
You wouldn't need anything that big though - modern DC circuit breakers are still made, some designed for boats and RVs which have DC power systems, and higher voltage versions for industrial electromagnets which run on several hundred volts DC. You might even be able to use the type of solenoid relays used for switching car starter motors on and off, since those are designed to handle DC at hundreds of amps. So safe battery management for 120 volts DC is certainly possible.
Overloading the input bridge rectifier on a SMPS is a possibility for the reason you mentioned, since running DC through them would send the power through only 2 out of the 4 diodes. There are a couple of ways to mitigate that though:
(1). If you were only ever going to run the computers directly from a 120 volt DC UPS the way I described previously, all the bridge rectifier would actually do is ensure that the SMPS circuit received the correct polarity (one of the uses for a bridge rectifier is as reverse polarity protection). So provided you ensured that the SMPS was getting DC at the correct polarity and within its working voltage range, it wouldn't actually need a bridge rectifier at all, so you could just remove or bypass it.
(2). If you still wanted to keep the option of running the computers from mains AC but wanted to also ensure that the bridge rectifiers in the SMPS units didn't get overloaded, you could always change them out for beefier versions rated for higher current. They are not that expensive, and they are also fairly easy to find on the circuit boards inside the SMPS units. So de-soldering an existing one and replacing it with a bigger one would be fairly straightforward, and this would not affect the operation of the rest of the SMPS circuits.
I have thought about doing that for so long. Glad to see I'm not the only thing thinking in this line. Learned a few things from your video. Thanks!
Best video connecting diy, solar/generator, off grid, sustainable power management . thank you.
Loved this video, thank you so much.
Glad you enjoyed it!
Nice work. Personally I'd have mounted the UPS on some riser blocks to give the fan a bit more space, but that said, it's still a very neat package.
I used to be in IT, and we'd frequently remove and scrap large server UPS units. Companies tend to have service contracts in place that includes checking and servicing their UPS units, and these companies tend to see batteries as consumables, so the batteries in many of the unit's we scrapped were less than 12 months old. It felt like a waste to let perfectly usable batteries go for recycling, so I managed to persuade my boss to let me scrounge a fair few 6 to 12 month old NP12-12 batteries for free (My favourite price ! :D).
I didn't really have a plan for these batteries, so I just daisy chained them all in parallel on a charger in the garage for about a year, but then one day I decided that if I didn't do anything with them it would have been pointless getting them, so I tested them all and matched up 16 batteries that were pretty much identical, then mounted then in groups of 8 in 2 heavy duty plastic toolboxes. I mounted a breaker switch, a voltage gauge and a pair of waterproof XT90 connectors on each box, then wired the batteries up in 4 groups of 2, all in parallel for 12V, and with each group having a fuse. The idea is if one in a pair of batteries goes bad and the other 6 try to rapidly equalise the voltage, it'll blow a fuse and then I only have a faulty battery (and one that's probably been damaged from over discharging) to deal with, rather than 8 damaged batteries. It also means that if a fuse blows it just becomes a 6 battery box until I replace the questionable pair, rather than a completely unusable box. This all get's me a total of 194Ah (2,304Wh) of capacity, but due to lead acid based batteries not being particularly happy about being run flat, I've set a much more battery life friendly 96Ah (1,152Wh) output limit for the pair. Because the batteries were free it turned this little project into a ridiculously cheap emergency power solution.
These boxes now sit next to my desk, permanently connected to a 20A storage charger. Sitting on top of that is a 3rd identical toolbox which contains 2x 700w (1500w peak surge) 12v inverters, a 300w (600w surge) inverter, several XT90 to XT90 cables, various adapter cables to take XT90 's to things like XT60's, barrel jacks, battery clips, 12v car accessory plugs, and USB chargers, a couple of cheap inline "RC hobby" type volt meters that also log total amp usage, a plug in mains power meter........... And a horrendously power hungry 12v travel kettle (What? I'm not letting a power outage mean I can't drink coffee, am I !!!! :D). There's also a 12v soldering iron wired to an XT90, a selection of bare plugs, a couple meters of a few different gauges of wire, and a roll of solder, all in case I suddenly realise I need some adapter cable I hadn't thought of after the lights go out. :D
I've already got a 1600w UPS on my main PC (I've upgraded the battery setup on that. It had 3x NP7-12's in series for 36v, so they came out and it now sits on a case extension that houses a 3P3S configuration of NP12-12's. While doing that I also noticed that mine had a couple of unpopulated spaces for 2 pin fan headers, so I soldered on some sockets that I salvaged from an old motherboard and, hey presto, they just worked. So...... Bonus !), this means the toolbox battery packs are really just to run anything else I want to use in a power outage. If power looks like it's going to be out for several hours I can drag these down to the kitchen to run the fridge and chest freezer for about a day, run the modem and wireless router pretty much indefinitely to get internet access back (Here in the UK, phone lines HAVE to be powered independently, so things have to be getting REALLY SERIOUS before the phones don't work, and according to a mate who works for the UK's main phone company, that includes any data that flows through those phone lines), or just run the modem, and a TV so I can sit back and watch Netflix for significantly more than a day while waiting for the lights to come back on. :D
Fan has more clearance than first appears; compare position of fan intake and the velcro at 27:46 and position of velco and the channel in the battery box lid in the side view at 30:15.
That's one heck of a setup you got! Definitely the way to go if you can't let something as minor as a blackout get in the way of your work, leisure, or hot beverage of choice. Unfortunately I have more limited access to scrap items now, between a change in jobs and increasingly strict rules against scavenging at recycling areas.
I have yet to see if the network stays up during an outage. I have a suspicion it may also go out since there's an outage notification soon after the blackout begins, and cell service noticeably degrades as well.
A fully charged battery is a happy battery.
At 13.8 volts, the UPS is providing float charge for a gel-cell battery.
This will not satisfy the AGM.
If you want long life (up to ten years), I would disconnect the battery from the UPS and connect an automatic (smart) charger with AGM charge parameter selection - about once a month. OR, at least after any significant discharge time.
13.8 volts will never fully charge the battery.
nice project, thanks for the video!
Thanks for sharing your wisdom! That's essentially my plan to exercise the battery now and then. Based on historical data, I'm expecting at least one power outage per month on average. The UPS will take weeks to recharge on its own, so I'll use my external charger to boost it back up afterwards.
@@MetaphysicalEngineer Perfect!
I do the same with the factory AGM battery in my Prius.
The UPS came with an AGM battery. the float voltage is probably at 14.5. This will cook a FLA battery. I'm speaking from experience here. Built one of these a while back and it just cooked the batteries dry due to the 14.5 float voltage. It needs to be somewhere around 13.5 for FLA batteries.
13.8 volts is the float charged for a lead acid battery,same reason most radio power supplys are 13.8 not 12 volts
Could you not connect a standard 12v car battery charger to one of the outputs on the UPS to keep the battery charged? Or does it need to go through the internal circuitry?
i also did something like this. got a few ups that where throw out. i got a 60AH lithium battery with it's own bms. ran some wires out from the 600VA ups. works well for 12 hours for my nas. only catch is it take day plus to charge up again, which was expected as lead charges at 0.7A
Cool to hear another success story! Be thankful yours charges in a day; if my rig gets drained significantly, full charge would take days to over a week. I'll have to connect an external charger if I want to boost it back up faster.
@@MetaphysicalEngineer that is exactly what i had to do the other day as there where few power outages in one day.
you'd enjoy having a chamfer bit to tidy up the holes. safer, faster, and neater than the blade knife. :D thanks for sharing this build.
I realized too late that I had a lot of holes to drill and my deburring tool was nowhere to be found! I've since gotten a replacement and will be sure to have better finishing tools if I ever need to punch a ton of holes in an enclosure.
Very cool, man. Thank you for posting this. It reminds me to perhaps do better with what I was supposed to have learned in my BSEE degree (read: they taught it, I just didn't try hard enough and it's been years).
A lot of my hands on skills I learned as I went. The best time to start was years ago; the second best time is now. It's only too late when you're gone, so if you're interested, there's never been more resources available for inspiration and learning.
Nice. I personally use an old APC SmartUPS 1500 to cover my router, wifi kit, TV, and a LED light in our living room. I use a large old car battery which is in a vented garden box just outside on our patio. We have lots of powercuts which is why i did this. Its enough to run the LED light and our internet kit for 4 hours. Plus the expensive TV is protected against spikes from the outages.
Excellent video! Most was another language, but I stayed for the whole build.
Cool project! Gives me a couple of ideas for my own. Great work.
Interesting project. I'm pretty sure that your APC unit is PWM sine (crappy wave). I chose a small true sine wave (BSINE600 from Tripplite) inverter instead. The SLA batteries in these units are good for one or two shots at high load before they go bad, so i just left the original blade connectors for connecting the SLA battery and made an adapter to an XD90 connector. Then made an XD90 to lug connector adapter cable and hooked up one of the cheap 50AH LFP batteries (probably cheaper than your group 34 deep cycle lead acid battery) which only weighs about 9 pounds. The 13.5 VDC charging voltage from the Tripplite charges the LFP battery to about 96% of it's total capacity, which works great. I have been using this one for over 2 years now and it keeps the internet router up for almost a day, or my laptop and the router going for about 10 hours or so. Hopefully more people will be inspired by your video to "ditch the SLA" boat anchors that come with the vast majority UPS systems today and have a UPS that actually will run a higher load for several hours all while doing it yourself!
Those are impressive numbers, John! Thank You for the details.
Very interesting! For a future upgrade or repeat of this project I'll look into alternate batteries, though I personally don't trust lithium chemistry batteries unless on a dedicated charge controller designed for such. Building a charger mod would be an fun project!
You're right that even a relatively inexpensive UPS could deliver much better performance with a lithium, though from my quick estimates, that would double the retail price of a smaller unit such as mine.
@@MetaphysicalEngineer LiFePo4 would be fine there, with the stated max voltage and a BMS (which the mentioned packs include), and perhaps even safer than a marine lead acid battery. Now, lithium NMC (typically known as Li-ion) would not be quite as safe.
nice engineering , but the max 200 watts isnt enough power and board/mosfet will eventually fail ..... better and easy to buy 1500-2000 watt inverter amazon etc $130 bucks and run 1 lithium 100amph and 2 decent size lead marine batteries mixed --(yes together) they work great together, compliment each other and many boat guys do it , then you have mucho power .
Nice to know something I did WAY WAY back in 2000 is being done today. People thought you would Burn your house down doing this. APC makes SOLID GEAR! In fact if you have a tired automotive AGM car Battery? I have used an old APC unit to "Charge it" (REfresh it) to bring it back to life from sulfation.
If you ever want to test if a battery can really pass a load test on the cheap? Pick up one of these UPS units.
I like the Cyber Powers as they have a display. But the APC units are built old school & SOLID.
There is a 24 Volt unit that has a fan built in that needs to be replaced after a few years, but is a great unit to use with large and CHEAP standard automotive batteries. You don't even NEED Deep cycle batteries. You tend to barely use the deep cycling feature, so if it saves you money? Get the cheapest walmart battery you can get and enjoy.
Very cool that you had success with this type of mod in the past! Interesting that your APC unit had a desulfation cycle. I'll have to monitor the voltage to see if mine has anything of the sort. Agreed that the internal parts are more robust than I thought; I went in expecting a struggle to keep the components from burning up under sustained load.
This isn't a Walmart battery, but similar in price. Was actually slightly cheaper than the starting battery of similar size. As for the deep cycle properties, depending on what I'm in the middle of, I may actually drain a significant portion of the battery if I have a deadline to meet when the power goes out.
@@MetaphysicalEngineer : Probably less a desulfation cycle and more simple-mindedness on the part of the UPS.
I've heard that since Schneider bought APC (Feb. 2007), the quality of APC UPSs has decreased, but I don't know whether that is true. Cyber Power is a different company, a competitor of APC.
lead acid outgassing does not only happen with higher charge rates and float voltages. give that wet battery a good discharge and then put your ear to it while it's charging and you'll hear it bubbling away. you did so good with the rest of the safety aspects of the project, should add a vent line to outdoors or switch to a big SLA.
LA batteries are placed carefully in cars to account for the corrosion produced in exposed metal near gassing batteries. On my Toyota Van the battery was in a side compartment exposed to moving air and even so isolated, still rusted the sheet metal around it. Mind you, in 5 years on a new car maybe not an issue. My van was 20 yrs old. I can only imagine what it does to electronics like the UPS.
Meh, no, I have listened to flooded lead acid batteries charging all the time, specifically to listen for the bubbling and they usually don't at a reasonable charge rate, until fully charged. This is further demonstrated by plenty of flooded cell batteries in real world applications with constant float charging that do not end up dry after a few years.
I recently found that those oscillating saws work amazingly on these abs or other similar plastic cases. (If you need a straight cut)
Thanks for the tip! Didn't think to try the oscillating saw. I'd worry it would bind up in the melted plastic and simply vibrate the workpiece instead of cutting, but I'll give that a shot next time.
Originally might have been made “Over Seas”: Improved in 🇺🇸.
Our cable modem is in the garage. My backup solution for it is a little Eco Flow River 2 power station, clip clip the power cord for the cable modem and run 12V from the power station directly to the cable modem (since it takes 12VDC on its input). By leaving the AC inverter turned off the power station can run the cable modem for 3 days easy on its own during a power failure.
Generally speaking, these UPS solutions are built into a lot of power stations these days so even for running AC devices it is pretty trivial, and you get a lot more backup time with a power station than you do with an APC UPS.
-Matt
Skipping the conversion is a smart move if the devices allow it such as your modem, and those Eco Flow units have impressive specs! Something I'd look at for adding additional backup power in the future that I can also easily take with me, though two things give me pause for my current application at my workstation:
Published switchover time could be fairly long at "less than 30ms", since typical UPS promises a tighter range of 8 to 12ms. My PC would likely drop out if under load since ATX spec is hold up time of 16ms.
Also, the 256Wh capacity is extremely good in such a small package but only 1/3 of the capacity of my homebrew setup. I'd need one of the Pro versions at more than twice the cost to have comparable capacity.
@@MetaphysicalEngineer Yes, but you are using a marine battery in what is potentially a home environment, and you are trying to maintain it with the charger controller from a UPS which is designed only for SLA batteries (which can take more of a beating to be frank). Outside of SLA, lead-acid batteries need to be well ventilated. The failure mode for lead-acid is also a big problem. Even UPSs have a hard time detecting that a battery has failed... usually you don't realize it has failed until you actually have a power failure and your "UPS" drops out after only a fraction of the time it was supposed to last.
So while it kinda works, it isn't really a robust solution.
There are better ways to go. The direct DC solution works for most small devices and will run those devices 2x to 3x longer from the same storage capacity. A LiFePO4 battery, a float-capable charger, and the device (for 12V), and throw in a 12V-to-5V dc-to-dc converter if the device runs off of 5V (the voltage is marked on the devices. 95% of devices these days run off of 5V or 12V).
That is a solution that will last 15+ years hands-free. Not even needing a power station.
Power stations are pretty good solutions unto themselves, and one can expand the capacity simply by fronting the power station with a 12V battery that you plug into the power station's "solar" input. Again LiFePO4 is the best solution (for the power station and the expansion battery), and one does need a way to charge the expansion battery.
Another "expansion" solution for a small power station is USB-C. Some power stations can charge from USB-C, which means you can just connect a power pack with a USB-C output (uni directional) to the power station's USB-C input to expand its effective battery capacity. At least as long as the power-pack doesn't timeout and turn off its output. Wall -> powerpack -> powerstation -> device. Like that.
But yes, most power stations have poor AC inverter "UPS" switch times... usually 20ms to 30ms when you really want 10ms-16ms. The absolute best case is 8ms (half cycle 0-current crossing on the AC waveform). Commercial UPSs can do 0ms by leaving their inverters energized and synchronized to the mains.
-Matt
i love that model and general design of UPS from APC. they use the SLA batteries that should be replaced about every 3 to 5 years depending on how bad your power system is (the utility). my goes down completely about 20 times a year and i have to replace the SLAs i use about every 3 years. the APC ones are by FAR the easiest to service. takes about 5 minutes. it actually takes way longer to source the replacement because you need to make sure its the right dimensions and tab size lol. pro tip, don't stockpile SLAs if you can avoid it. they have a shelf life and its the same shelf life of 3 to 5 years, even on a trickle charger
Nice build.
Great, clean job. Love your attention to details. Properly done cabling and connectors goes a long way. My only (small) concern is small distance between box top cover and UPS leaving rather small space for air inflow for fan. Probably it's sufficient but I'd add some more distance, perhaps a piece of plastic, like a short pipe or a piece of cable tray or sth like this. Not sure it's needed, perhaps it's just my habits :) Anyway, great job!
Very nice repurposeIng of old UPS. Well thought out and implemented. I am now keeping my eyes open at rummage sales, 2nd hand stores, and Goodwill for a used UPS.
I was concerning building one of the solar generators as seen on TH-cam. I want something to take camping or use in an emergency. But your project got me thinking about merging the two, something that I can use as a UPS at home and a solar system that is portable.
The way I invision it, I wouldn't need an external charger circuit, or AC power inverter if I start off with the UPS circuits.
The thing is, I'm NOT an engineer and don't know how to marry the two projects, and I don't want to do something that has electronic or fire risks. So I'm hoping you might help me by building a project that I can copy. ;-)
Thanks for stopping by! Your idea may actually be simpler than expected!
A solar panel with a smart charge controller can feed the same battery as the AC charger in the UPS. All each charger does is interpret the battery conditions and supply carefully regulated voltage and current as needed. When the AC power goes out, the UPS inverter will kick in. As you see when I was testing the unit, simply pressing the power button when the unit is unplugged will also turn the inverter on or off.
You are wise to be hesitant about fire risks, hence why I was careful about sizing of fuses due to the huge amounts of energy available from a such a large battery.
My main hesitation after that is a UPS is heavy and bulky compared to a typical inverter of comparable power output. Technically portable, but less practical for camping when weight and cargo space are limited. With everything together, my system here weighs in at over 70 lbs (31.8 kg). I can lug it around, but would not want to do so often.
Honestly if you can afford it, I'd recommend something from the Ecoflow River 2 series if you don't feel too confident with what you're doing were you to build your own. Of course what I think is rhe best option is to research until you are confident. And this is coming from someone who built her own full house backup's battery from prismatic cells and an off-the-shelf BMS to connect to a hybrid inverter.
If you dislike my recommendation for a ready to go option, there are other brands with useable offerings but i wouldn't trust bluetti in UPS mode for critical loads, my network has already gone offline times enough from such trust.
@@lua-nyaepic ❤
I'm just getting into electronics and have had some UPS, so this was really cool to see.
Clean re-use of a UPS! I've always wanted a good computer UPS that allows an external 12v battery via plug, for my mini server farm.
There are models out there geared toward enterprise applications that have provision for external battery modules. Starting with one of those, much larger custom batteries can be installed like what I did here. Added benefit of high output pro grade units will have internals and cooling rated for extended operation, so no need to hack in a fan.
you reminded me of the old days, we did that 20 years ago to keep power in the house during the war but had 8 batteries connect it on it :D
This is so funny! I have this same exact UPS. I replaced the battery once about 5 years ago, and it recently died again. I bought a new large UPS. This would be a cool project for it!
23:35 FABULOUS PROJECT! I’d have moved the volume pot to the cable side, to avoid having something stick out the top.
Nicely thought out and executed
FYI: if you can find the cable to connect this to USB on your PC and download the software you can adjust the runtime and alarm settings as well as thresholds for triggering a switch to battery power such as the voltage min and max. Typically they default to turning off the power after a few minutes to give the PC time to shutdown and maintain a charge in the battery, I changed mine to run as long as possible regardless of the capacity of the battery.
Interesting that the software has all those options; I'll see if I can get a cable and a version that works since this unit is 13 years old by now. As far as I can tell, this one will run until the battery's drained or an overload occurs.
@MetaphysicalEngineer Powerchute works just fine, they havent changed much of the software or the UPS in decades, so not much is updated.
Any recommendations for version? The old ones are listed as discontinued, and the new web based one has abysmal reviews.
@MetaphysicalEngineer I'm running powerchute personal edition 3.1.0. Looks like it was last update in 2019.
Nice! I had a bunch of batteries laying around already so I basically did the opposite, picked up a 1kW pure sine inverter and put that before the UPS. Eventually I'll probably make a failover system so it can switch automatically, since I don't have to worry about the switching time due to it being before the main UPS units. Maybe also hook it up to weather so it can precharge before a storm... yay scope creep
A week before that however (because of course) I had multiple 24hr+ power outages, and ended up doing pretty much exactly this, but with a power supply powering the UPS off of said random batteries plus a pile of sketchy AF car inverters lol.
Nice job. I have a 20+yr old apc 2200 with an external connector for battery packs. Only downside is it runs from 48VDC & I'd have to drill a hole in the floor down to the garage to add more batteries.
Thanks for stopping by! Understandable that it's a pain to run remote batteries like that. Is putting the UPS down in the garage next to a hypothetical battery bank and pulling a "surge and backup" AC circuit up to your workspace an option? At least for me I'd rather fish romex or armored cable than a set of heavy gauge 48VDC wire...might be cheaper in materials too.
I used UPC similar or just like this for years. Just drilled hole in battery cover and ran right to car battery. Never had any problems if I only connected it to computer and monitor. Much larger UPC units are available for cheap or free that just need a battery. No mods required. I only use semi-sealed batteries (tops don't come off) for less gassing. And I only use APC brand UPC. Less likely to have problems.
I did this with a couple of them. I removed the battery and put in a PC fan and a small 120-12v PSU for it. I ran it off the inverter outlet rails. I broke out the wall between the battery compartment and electronics area. These are underrated to have passive cooling. With forced cooling they do so much more. I also partially bypassed the amp limiter.
Another success story of a hotrodded UPS! 120V to 12V converter was an option I thought about for the fan, but just didn't make as much sense to me since the unit already had a 12V source right from the battery.
How much more capacity were you able to get with the current limiter bypassed? I imagine at some point it just bogs down too much or the transistors give up regardless of cooling.
Cool. Will probably do something similar. Use a big rack ups next to my desk. I put a pwm fan controller to turn down the volume and keep it running all the time.
Subscribed just because of this video. Took my apc added a second battery and volt meter.
My type of diy.
Great job
Awesome! So cool to see my project inspiring people! Not every video will be like this, but there will certainly be more such projects in the future.
And when a fire inevitably happens, your insurance company will refuse to payout and this video will be entered into evidence as to why.
I did one similar a few months ago, I just rectified the drains of the main mosfets and that gave me 12V for the fan. Mine is non-isolated (FSP), so a solid battery box was required, but the low loss and ~70W load it feeds gives me excellent runtime on 50Ah. Enough fuses were added.
That's a clever idea using the inverter input stage! It's cool to hear about the similar success stories beefing up UPS units for extended runtime.
Lol 😂😂😂 thanks ❤❤❤
I did a similar project for my network. I used an APC UPS from a Walmart Self-Checkout and it ended up having a pretty efficient switch mode power supply instead of the huge 50% - 70% efficiency transformer that most of these use.
Interesting that the self checkout uses a different circuit setup more similar to a mobile inverter. What size battery did you use, what load are you running, and what runtime are you able to get?
I did this back in the day with a "bad" 3000VA ups. It was 48v. Bought 4 AGM boat batteries. It could run 4 computers for several hours.
Its alot easier to use self tapping screws for creating pilot holes in plastic when you have no anchor. It is also a lot safer than doing it with a drill. Get screw and hammer. Hit it with a slight tap in the spot you want (this acts like breaking the glaze on a tile.) Then use you cordless screwdriver to do the rest. Great vid by the way.
You are out of your mind if you think it is safer to the enclosure to be hitting a self tapping screw with a hammer. If you have no concept of drill depth limiting, the last thing you should involve is a hammer, lol.
@@stinkycheese804 you have obviously never done this.
On the contrary I could MORE easily state the same about your (in-)experience. It's idiotic to hammer self tapping screws into anything, especially thin plastic. Hopefully some day you will learn how to use a drill properly and open up a whole new world of hole making, lol. @@plebius
@@stinkycheese804 you are talking about depth limit on drilling a unsecured piece being handheld. That slipped numerous times.
@@stinkycheese804 I also thought it was obvious when saying pilot hole, you still use a bit in the handheld screwdriver once you create a pilot hole. Hence me saying you haven't done this. Glhf
Hey, thanks for the video. I now have a better understanding of what one is actually buying when one buys an inverter, and why they often *seem* so different from a UPS even though in principle they're doing the same kind of thing.
It's all about the waste heat which sorta kinda varies proportionally to the amount of time the thing is on battery mode and the amount of wattage being pulled.
I don't have the skill, patience, or tools to build one of these out of the similar UPS I have that also has a dead battery.
But it's neat to see how it works.
excellent work next time don't trim strands off the wire not that its a big issue but I stick an "ALL" or a pic in there and widen the aperture to fit the wire as its a crimp anyway it may buy you a bit more where losses are concerned if you are looking for every bit. I often upsize my conductor runs for solar to help with losses.
I really didn't want to trim that much. Somehow none of the places I went to had 3/8 terminals for 8ga wire in stock.
Also funny how an automotive or marine ampacity chart said I could use as small as 12 ga at such a short run. Based on how warm the 10 got during testing, 12 would be cooking at sustained load!
"All"=Awl
@TechReclamation - Cable gauge, or cross-section losses are only significant over some distance when the resistance adds up. Over a distance of maybe 0.2mm between the trimmed strands and the crimp, the losses would be completely insignificant. After all, consider the tiny cross-section of just the stamped steel in the neck area between the crimp and the actual load connection....
@@xNYCMarcthanks, I was quite confused there.
I've been known to remove the plastic from a terminal and open it up a bit by splitting the end. Sometimes it's already cut so you only need to separate it, otherwise a Dremmel helps. Then slip some heatshrink over the wire, crimp it or solder it or both and shrink it down.
You should discover the wonders of a "Christmas tree" (otherwise known as a step drill). Much of this project would have been much smoother with one.
Indeed, I realized too late just how many holes I was going to drill and that my deburring tool was nowhere to be found. I'll be picking up a step drill next time I'm at the hardware store as well.
Ah cool, you pretty much built a Tripp Lite APS though the APS had less smarts. Fun project, nice video.
I just need to supply a small load (my little web server + modem & router), so I didn't bother with all that stuff. No fan, no battery box. I just spliced a couple of cables with battery clamps on the ends, in place of the original 7A battery, drilled holes in the UPS box for the two wires, and put the UPS on my desk next to a car battery. (If I'd been intending to power a larger load then I'd have added a fan.)
One advantage is that I can swap batteries without shutting anything down.
Another advantage is that I always have a fully-charged car battery, ready to go, in case I need it.
The first time I had a power outage, it worked fine, but the beeper was intolerable. So, after the power came back on, I removed the beeper.
The next time I had a power outage, it lasted 6 hours and 40 minutes! My UPS kept my website up the whole time. Nothing ever smelled hot, and the UPS never got warm to the touch.
I clipped a multimeter to the battery terminals, and the voltage decreased by a little over 1v over about six hours. I suspect it was near to shutting down by the end.
Sometimes that's all you need to hold out through an outage! I like the concept of hot swapping external batteries as needed.
I've not yet found where my unit will cut off based on voltage, but I'm guessing somewhere below 11 volts since it also assumes the battery voltage will sag under load. You may have had even more runtime remaining than you thought.
I’m watching your video on this ups, and get blown away when you bust out the field piece sman Hvac gauges. Now I gotta dig throuh your channel to see why you have EXPENSIVE HVAC tools on your workbench. I have several sets of them in my HVAC service vans.
I used to work in HVAC and refrigeration but got hit with a career-ending back injury earlier this year. Fine now but high risk of repeat if I go back to heavy trades work. Getting forced to take a step back revealed I wasn't where I wanted to be after all. I am considering getting my license at some point, if only for easier access to certain equipment and parts. I've torn down a compressor with valve failure on here, and have a second compressor with a suspected broken crank also waiting for teardown sometime.
@@MetaphysicalEngineer I’m old school, got my licenses at 17 back when all ya had to do was take the tests.
Nowadays, all the insurance and work hours experience needed to qualify to even take the tests slows most from getting licensed.
Lemme know if ya need any assistance with anything. I put your video on diysolarforum it should post up after Will Prowse reviews it.
See if we can get you some exposure for a nicely done video.
you can also use a stepped bit as an impromptu deburring tool.
Funny you'd post this. We have similar power issues where I live. I'm already using a 'failed battery' UPS for surge protection and I've contemplated this exact modification. Now I know what I should be checking before I do the work. Thanks!
Yeah, a step bit would have been helpful at multiple stages of this project. Another thing I rarely used (borrowing the boss man's kit when needed) but maybe time for one of my own.
A word of caution from another commenter is checking that the battery side is isolated from the line voltage side. Some units use a "line-interactive" type circuit where significant AC voltage can be present at the battery terminals and could give you a nasty shock if you do a USB charger or 12V socket like I did. Measure between battery negative and ground. You're safe if they are tied together, but beware if you get voltage there!
@@MetaphysicalEngineer Wow! I'll definitely check for AC voltage at the battery, It's kind of insane that a USB would be built that way. I lost a battery in my 1948 Willys CJL because the diode pack on the alternator failed and was bleeding AC power into the battery.
FWIW, Harbor Freight in the US carries stepped bits for under $25.
Great reuse! There are a lot of these desktop SOHO UPSs' out there and they die all the time. It's important to note that not all car batteries would be safe for this use. This needs a sealed battery to prevent off gassing as that could create an explosion.
Offgassing is extremely small with a single battery at very slow charge. This is an older house not a hermetically sealed bunker or vehicle cabin, so any gasses dissipate quickly. If I had a bank of large flooded batteries under heavy cycling, I would need forced ventilation, hydrogen detectors, and catalytic recombiners.
Good work. A quick note... you absolutely can NOT use a clamp on amp meter to read DC current. Think about it. Only an alternateing current will generate a magnetic field for the clamp to pick up. For DC Amp you must use a calibrated "shunt" (precision high wattage very low ohm resistor). Measure the voltage drop and use ohms law.
You're right that the regular current transformer clamp meters only measure AC. Meanwhile, Hall Effect current sensors can measure either AC or DC. Most manufacturers have at least one model in their lineup with that function. My RadioShack meter uses a Hall sensor, but I didn't notice the glare and foolishly expected the camera to capture what was on the display rather than recording values manually.
Did this a few years back with a spare inverter and some used solar batteries from a friend who was upgrading to lithium. My home datacenter can run for about 24 hours on the batteries if I shut down everything that pulls a lot of power (ie the desktop and PoE switch). Enough to keep the internet going for a while during power outages, which is nice when storms roll through.
That's how to do it! Hence why I keep have one monitor stay running during the transfer and I'd shut that off too if I had to keep things up for a while.
My parents have a few batteries and inverters they use to keep things running during storm outages, as it can be a while before they get power back. Storm raging outside while they're happily siting by the gas insert with a lamp and their laptops, all running off the backup batteries. They can even run the central boiler to keep the pipes from freezing if the temps really drop.
Nice! I got a nice free older but high-end UPS (APC Back-UPS XS 1200) of similar design, even with a brand new battery set the previous owner tried changing out. Unfortunately, it appears (reading data from it over APCUPSD with a special USB cable) that it is sensing AC input voltage as being chaotically all over the place (frequently outside the loosest tolerances the firmware will allow to be set) at all times (even when unplugged?), and refusing to switch from battery to line power due to this perceived unstable line voltage. As this sensing appears to take place from a pair of resistor chains from the high-voltage side heading into what I believe is a TS358CS double op-amp amplifying the difference between them (who's other connections are difficult to trace) and thus doesn't contain any components that seem plausible to wear out over time or easy to test, I'm not sure what I can do to fix it, at least not without a schematic to figure out all the other connections going on.
Could worn-out electrolytic capacitors be causing the device's power supply to leak enough noise back to where this voltage sensing is going on to interfere with the process? Replacing the through-hole electrolytic capacitors would be a relatively simple matter of ordering similar parts, but if it's not that I have no idea where to start.
I did something similar to this maybe 20 years ago with a HUGE old APC unit that ran 2 12v batteries in parallel. I used a pair of Marine batteries which are better suited to being discharged over a long period of time. It would run my 2000s PC, dual 19" CRT monitors, and network gear for at least a day. Honestly I never was able to run it long enough to run out of power. A bunch of internet "experts" informed me I was going to blow myself up because of the tiny amount of hydrogen released from the batteries during charging. I'm still here.
I have that exact model. I love, though, it needs a battery. I upgraded to a more powerful unit, but I'm still going to replace the old battery in the 550VA
Love your HOT PINK GLUE GUN!!...LOL
It videos like this that remind me why I wanted to study electrical engineering.
There's nothing stopping you from learning it as a hobby if you're interested. There's more resources now than ever!
it's cooling fan, for cooling when it gets too hot? so at, 6:51 the fan running all the time when it unplugged, that the wrong problem/logic you are trying to solve? the correct solution if the UPS gets to hot, and it would not matter if it was plugged in or not its getting to hot? so, it the such a thing as thermal trip, like the ones you get hot water kettle, boil dry, detector not that world work works by switching on power instead of powering off, and at a more desired lower temp. cut on instead cut out?
Original UPS did not have a fan or logic to control a fan. I built the fan control circuit so the fan only runs when the UPS is powering something using the battery and inverter. A mechanical thermal trip like for a kettle safety switch was an option I thought about, but difficult to detect the temperature of components most in danger of overheating (MOSFET and inside the transformer). Electronic temperature sensors would be a more complex circuit. I already planned to add a volume knob to the alarm buzzer, so I used the alarm signal to control the fan as well because the alarm only turns on when the inverter is running.
Great video.. 2 years ago I got given a apc750va unit for free from work ..I've added better heatsinking and a cooling fan and it runs from 3 car batteries recharged from 2x120w solar panels... Runs my workshop networking gear and pc for hours ... I've never managed to run the batteries out before the mains power has come back on ...but it's in excess of 3 hrs .... Also allows me to recharge laptops and power tools 'offgrid'
I also have some 3kw 48v tripp-lite units waiting for when I can get some cheap car batteries...those things are built like tanks.
Very cool! Awesome to hear about so many people building super UPS systems. Sounds like you know what you're doing but obligatory caution about how spicy that much battery power can get, the need for matching battery capacity in a series string, and the need for ventilation. One battery on float charge doesn't offgas much, but if you have a rack of standard car batteries on a much faster charger, you'll get more hydrogen.
I used one of these that I had laying around and replaced the internal battery with an 18 amp hour battery. it takes a long time to recharge, but it does work. I didn’t need a fan because I’m using it to run a router that only draws about 10 W. it keeps my Internet up for 12+ hours when the power goes out.
Nice! Sometimes internet and a way to charge your phone is all you need during an outage. May parents do a similar thing with a big battery and inverter since their area is prone to outages in winter storms and low on the priority list for getting hooked back up.
Thanks for the vidja.
Peaceful Skies.
Very well done. Thank you for sharing your work; a device like this is attractive for keeping a photo printer running long enough to finish a job. A company called Noga makes excellent tools for deburring holes, if you're inclined.
Thanks for commenting! Yes this would also be great for printers and similar where a power cut could ruin the batch and waste material and time. Doubly important if there's a deadline to meet.
Since I recorded this video, I finally gave up on finding my MIA deburring tool and acquired a new one.
i run an RS1500 with 2 deep cycle battery's keeps my 2 TrueNas and router going for a safe shut down. but all so keeps my WiFi and an energy light going for a day
That's how to do it! It's really cool seeing how many other people have successfully done this type of modification. Video work is only a small part of my job, but the disruption of a power outage alone and sunset happening at 5pm now drove me to do this project.
This is Great :) I have this same UPS running my Router and Internet box, ( its a old one I had from 10 years ago)
Thanks for stopping by! These units are great for small loads right out of the box, but most use cases aren't expecting to run at full power for extended amounts of time like I needed here. My parents don't have a UPS but do have some big batteries and inverters to keep their equipment running. A couple years back my dad texted me a pic of him and my mom and the cats watching TV like nothing was wrong despite a snowstorm knocking out power all day.
@@MetaphysicalEngineer I work on film set, Have rack mounted UPS for my Work PC/networking on a cart for and a Powerstation for when 45min on UPS is not enough.
Oi. Your fingers sent a message: please stop lining us up with the dremel cutting wheel (vice, jig, something that doesn't bleed and scream in case of accidents). Always good to see someone else do something to stick it to the UPS oligopolies.
I collect these from people throwing them out. I just order new batteries. First thing I do is clip the beeper on the board. I do get good used batteries from a buddy who changes out batteries on emergency lighting fixtures inn commercial buildings.some places change them out yearly.
Sir, I was an electrical engineer in the 1990's when I was in the Air Force. I absolutely loved watching this! What a great idea! How much did everything end up costing you? I've only just found your channel, but you definitely earned my SUB with this one, brother. I look forward to reading all the FAQ's below (I knew the Karen's would be screaming about off-gassing, LOL)! Anyway, looking forward to binge-watching some of your other videos. Shalom
Thanks for your kind words, and thank you for your service. The total was around $200, since I got the original UPS for free and added the accessories to the battery box myself instead of spending $100 or more on a prebuilt one.
Had one of thse where a small amount of liquid got into the inverter side plugs.Popped it open dried the liquids up and for good mesure tightend the loose metal of the plug contatcs.
I tried this once, but gave up immediately once I learned the UPS I was using had a history of short circuit and fire risk issues. Fun project, but I'm not looking to burn the house down. Can't remember what I used for the fan turn on signal though, but I know it involved making a NOT gate from a few transistors.
When you build a UPS like this without an SLA, then you need to add provisions for a failure mode where the BMS fails on and cooks the battery. this means you just have some sort of tray under the battery that you put something like baking powder in to neutralize any boiling acid that escapes the battery. You can simply just pour some baking powder into the battery box itself, which is what a lot of off the shelf solutions do. you just want enough powder such that you have an excess required to neutralize all of the acid inside the battery (its like a few cups or something). And then you also want to have ventilation of some kind. any kind of passive venting like just a door that is open or a cracked window or even just a return vent to a central HVAC will work fine. This is to prevent hydrogen build up in the case of a BMS failure where the battery boils but it will also eliminate any possibility of hydrogen build up.
With one battery though, hydrogen build up is i think impossible, at least you will never get enough to have a reaction. even if you had open sparks above the battery at all times, a single battery like this probably can't make enough H2. So i would just make sure its not in a confined space like sealed into a concrete bunker room with a sealed door. You only need H2 and active venting when you get up to like 10 of those batteries or so.
You also want a jug of unopened distilled or deionized water next to your UPS. i recommend having a 1 gallon jug because you can get them anywhere and they are super cheap. just get one and stick it next to the UPS. you will thank me in 15 years when you realize the battery is low on acid and you can just grab the jug to top it off. for a large set up with numerous batteries you want to use the actual acid, but for just one you can get away with using water. in my experience it takes something like 10 years for the voltage to start to drop from lower acid levels and you just need to add the distilled water to get the electrodes inside covered again.
or you can always just let it rip and not do any of that. really, worst case is the BMS fails on and boils your battery, the caps pop open, sulfuric acid boils and splashes out and leaks down the sides, and ruins the subfloor. worst case, you end up replacing like a two foot square chunk of carpet and subfloor. ask how i know hahaha
Adding baking soda to the bottom of the battery box is a great idea! Like the battery spill kits we kept on hand back when I coached robotics clubs. Though I imagine the battery charger will likely fail open circuit rather than full on. Other commenters have mentioned the charge circuit giving up.
This 1960s building is leaky and the HVAC cycles enough that buildup of gasses isn't a big concern for me. I think I'd need more batteries and a tightly sealed room before enough hydrogen could accumulate to be a danger. In that case I'd have AGM or LiFePo4 or rig up catalytic recombiners that intercept the offgassing and return the water to the cells, like what's used on large scale battery banks with flooded cells.
I have a jug of distilled water on hand already, and I'm planning on a quarterly or so test and inspection. My parents do that with their backup batteries now, after making the mistake of leaving them be and getting caught with crippled backup power one winter.
Thanks for the cautionary tale about the acid spill eating the floor. I hope I never encounter that issue!
we want more videos like this
More projects will be in the works for sure! Though given my range of interests and duties, a wide variety of hacks and repairs and more will also appear.
Easy "fitment" neat, it's like “gription" made up yet functional words are the best.
You could hang a small solar panel outside a window and use that to power the device while in standby mode. That should be enough to keep the battery charged. You would only need mains power if an actual load is connected.
That's a viable option since this side of the house gets plenty of sun. I'll borrow the little 18W smart solar battery maintainer from my car to see how that behaves. Anything would be faster than the tiny 3W charger in the UPS, though I fully expect to need an external mains charger to recover from an outage in reasonable time.
@@MetaphysicalEngineer That is the idea. Use mains for recharge, but solar for standby. with a bit of luck, it will give you enough power to charge your mobile devices for free. Not only will that save you some money, but you will have some power even in case of a prolonged outage.
Made similar modification, used TO-220 thermal relays (switches) widely available.
Another success story! Thanks for weighing in! Where and how did you mount your thermal switches on your unit?
I was concerned about the vastly different thermal behavior of transistors and transformer, and difficulty of measuring the hotspots.
@@MetaphysicalEngineer In my APC ES700 transformer is hotter than mosfets under 200-300W load, so I put thermal switch between housing and transformer core and fixed it with some heat-resistant glue. Made it about year ago, not sure about small details but overall concept is exact. Any thermal resistance between windings and core I've compensated using lower temperature switch, somewhere around 50C. The only negative side I've found since modification is fans work few minutes more than required after UPS switches to AC. However, during my experiments inner windings were about 20C hotter than outer, so it's pretty safe.
@@HeIsTheHighlander, can you please be specific about what thermal switch you used, and where you got it? (Don't specify a URL, because youtube will block your comment if you do.)
KSD-01F - first results via search "thermal switch to 220" with no quotes on Ali. Normally open for fan, meaning it will close reaching target temperature. They're made on different temperatures.
@@ncdave4life I've bought them both type (NC and NO) and almost every temperature, it was cheap include shipping to Russia, I think cheaper than $1 each. Not sure about exact numbers, it was a couple years ago. I think they should work in parallel, but in my case transformer was hotter than mosfets, so I used only one thermal switch.
Hey! I think I have this model UPS. Yeah, dead battery, too.
...
I also have a stack of that style protoboard. 😀
I did this back in about 1999 to several of my UPS's. I used lawn tractor batteries from Walmart. 20 bucks. Too bad they are much more expensive now. One of my UPS's was a sine wave type that was very expensive and also highly inefficient so it was already equipped with two lead acid batteries. But they had reached their end of life so the company junked it and it became mine. I put two used but still functional car batteries on it. It could hold up my computer for several hours.
BEWARE: Most UPS's put out a pseudo sine wave which is sort of a square wave. The problem is the edges of that square produce lots of high frequencies.(See Fourier transform theory.) If that voltage is applied to an iron core transformer like the old wall wart kind(all we had in 1999) that weren't using a switching circuit, then the high frequency eddy currents in the iron core will heat it up to the point that the safety heat fuse opens and the wall wart is dead. Those old wall warts can take that pseudo square wave for 10 or 20 minutes but much longer than that and it's curtains. The newer light weight switching kind are fine with that square wave.
And you know what I did don't you? I cracked open that wall wart and jumpered that safety heat fuse and it was back working. I left the plastic case off and always had it in a place where it got plenty of air to cool it off. Safety third.
Hmmm. I just took a 24v 900va and hooked it to two truck batteries and keep the load under 400 watts… runs for days, no overheating stock.
I did this with a ES-350 and an 100ah battery to back up my pellet stove and it worked ok without a fan but the internal charger could not bring the battery back up so I had to add a 5A charger. I also just put hot glue in the buzzer to mute it. I've since moved to a 1200VA ups which has a built in fan and it's able to maintain the 100ah battery on it's own (so far).
The charger is a weak point on these units when the battery is upgraded; other commenters have mentioned the chargers failing. Agreed a bigger UPS would have been a better starting point since the cooling and charger would be better suited to the use case I wanted. If mine goes out, I'll rig a more powerful smart charger to the unit. As of now I need to manually hook up a charger to make sure the battery recovers fully after significant use.
My parents use a big battery and inverter to run their central boiler through outages. I converted the boiler from hardwired to a standard power cord so it can be plugged in to mains or switched to an inverter. With careful management they can have days of heat, which is long enough for even the worst outages in their area to be resolved.
yeah i have done the same thing a few years ago,but i started with a bigger metal case UPS,just ran leads out and connected it to a truck battery
Cool! What capacity UPS did you use and how much runtime did you get from the truck battery?
@@MetaphysicalEngineerabout 350 watts,never found out runtime,it was hours longer than i ever needed,it might still be in my storage unit,if it is i'll get it out and take some photos
It's not clear from the spec sheet how much of an approximation the outut waveform is, but it says stepped approximation to a sine wave. Some equipment doesn't like that. Given the availability of cast-off UPSs, I'd hold out for a UPS with pure sine wave output. I used a Cyber Power 900AVR with two marine batteries when I did this the first time. That one also produces simulated sine wave AC, but also provides automatic voltage regulation for dips and has higher rated output so it should run cooler to begin with.
Stepped approximation means modified sine in this case. Waveform looks like off period, square wave positive, off period, square wave negative, repeat. Easier than square wave with no off period, but certainly rougher on some equipment. My computer PSU explicitly states in an FAQ that the input stage is capable of running on modified sine, but that may not be the case with all brands and models.
Wasn't sure the direction this video would go when I started. Could have been a teardown and analysis of a failed unit, replacing a dead battery, failure during the extended load testing, etc. Instead since it proved more robust than expected and how much that most recent blackout bugged me, I turned it into this project as shown.
Absolutely have plans for a future version 2 with a much better UPS at its core, possibly with high performance LiFePo4 batteries and hybrid grid-solar charging system. But that's way outside of my budget for the moment.
@@MetaphysicalEngineer LiFePO4 batteries are very cheap right now. Maybe getting cheaper? I just today hooked up a 4-pack of 304AH cells ($90 ea) to a Yeti 1250 to provide some serious capacity. The Yetis are discontinued and sometimes you can get one cheap. They have all the goods inside like pure sine inverter, a couple of different charging inputs with fairly large range of voltage (but limited to around 260W), older USB (1A?) and 12V accessory. I added a real BMS because the Yeti only knows how to handle AGM, plus it doesn's balance. You can run it without, but not recommended. That's one way to get started.
a small analog clock would be a nice, little and cheap addition to the segments you know you'll be fast forwarding :) it's your first video for me, you got a new sub :D
Good idea! Low tech but easy to interpret indicator of how much time passes! Thanks for subscribing!
@@MetaphysicalEngineer really just some kind of timer, but - don't ask my why - I felt a small analog alarm clock wuold suit it better :P
One thing I question: in the final assembly, isn't your intake fan between the UPS chassis and the battery box, with only a thin channel for air intake?
Ah, I should have gotten a better shot from that angle. The fan intake lines up with the channel molded in the battery box lid and the lift from the dual lock velcro pads securing the UPS added even more clearance. Plenty of airflow! You can get a rough idea by looking at where I placed the pads on the UPS around 27:45 and where the pad is visible just above the switch on the assembled product around 30:14.
I've actually done this to the ups that's powering my PC at home, though I didn't open up my ups. I just installed to parallel lawn tractor battery's on it. Though I've thought about using a generator hooked up to the DC side incase of long term use. Maybe solar
If you have a suitable DC generator, that would boost the runtime for sure. These units will likely handle input in the 11 to 15 volt range. Keep an eye on temps, as the internals will just keep heating up until something cooks if allowed to run longer.
I have been looking for a heavy-duty UPS unit for years that could just be hooked up to a large deep cycle battery either lead acid or lithium to run important circuits in my house we get annoying blinks in the power which I'M sure are not good for electronics. the electric company at first when i complained said nothing was wrong then after me calling a few times somebody realized a tree rubbed through the wires at end of block and was shorting them out in wind or rain. Still get some glitches but not as many now.
What is the potential difference (voltage) between the Earth pin and the terminals on the 12volt battery? Is the battery at 100V above Earth?
Battery negative is tied to earth, so a maximum of 13.5V DC above earth at the positive terminal. No risk of shock from the battery terminals as long as the building wiring is correct.
Could you Pin a parts list for this circuit board, please ?
Parts list, per request. Read datasheets and verify before ordering. I take no responsibility for any property damage, injury, etc. arising from attempts to replicate this project.
P1 | PTN16-D01115K1B1 | 1k Potentiometer 0.125W Any similar part will work
D1 | 1N456ATR | General Purpose Diode 30V 0.5A Any similar part will work
Qi | 2N4403TAR | General purpose PNP transistor 40V 0.6A hFE 100 Any similar part will work
Qm | IRLZ44NPBF | N-Channel MOSFET 55V 47A Threshold 2V Overkill for this application; any similar part will work
C1 | EEU-EB1E101SH | Aluminum Electrolytic Capacitor 100uF 25V Any equivalent part will work
R1, R3 | CF14JT1K00 | 1k ohm 0.25W Any equivalent part will work
R2 | CF14JT560K | 560k ohm 0.25W Any equivalent part will work
@@MetaphysicalEngineer ...Thanks a megaohm !
That wouldn't be quite legal to do
@@BurkenProductionslol what
Any chance you could share that tool you used for the battery run time @1:38 ?
You mean the overlay showing the calculations? Those are found on the APC website. Search the brand and model of the UPS and most will have a tool to estimate run time at various loads. Take with a grain of salt since those assume a new, fully charged battery and perfect operating conditions.
Careful lead acid batteries emit hydrogen. Otherwise solid build. I have done something similar and recommend Bigbattery lithium 12v. They are more expensive but more reliable.
Was wondering when somebody would bring this up. However, at 13.5V float charge and 0.3A max charge current, off gassing is minimal for a battery of this size. If I ever need to fast charge or exercise the battery, I'll ensure there's extra ventilation.
Lithium would be an option, as would AGM, with the downside of expense. Perhaps when this battery gets retired, I will upgrade to a safer, higher performance type.
Thanks for stopping by!