The reason that it drops just suddenly is that LifePo4 cells have a flat discharge curve so all of a sudden one of the cells drops directly from 3.3 volts to 2.5 or less in a matter of seconds this means that it has like 10%-20% capacity left so if one cell drops bellow 2.5 or it may vary due to different BMS's the BMS itself is shutting of the connection to the negative terminal. U will not hear beeping or anything just will stop suddenly. The other cause is related to the first one if you are running without BMS it will work just fine but if one of the cells drops with 0.7 volts the ups doesn't have time to beep for low voltage. For example the Lead Acid batteries have a more curved like discharge curve so it will steadily drop from 13 to 12.9 to 12.8 to 12.7 and so on so the ups itself has time to beep. Cheers and be careful of what you are doing man u almost needed a fire extinguisher !
good choice using LiFePO4 as a replacement. This chemistry is the only viable option when needing a replacement for 12v PB. LiFePO4 has a lower nominal voltage, where other chemistries, such as Li-NCA or Li-NCM, voltage can be too low at 3S or too high at 4S.
I'm wondering how those two short-circuits influenced cells internal resistances. I was once replacing ni-mh cells in old cellphone's battery, and I shorted one cell for good 5-10 seconds. From that point on, this cell had significantly higher resistance than other two. The capacity didn't suffer significantly though. Just a thought.
Higher ESR will dramatically affect the capacity at high current draw. I assume you tested your shorted cell at a standard rate of 1A which may not show decreased capacity but certainly it will be reduced at higher loads
A home computer UPS is a "stand-by" (as opposed to the more expensive "continuous"} power backup. This means that devices connected to it run directly off the grid mains until an interruption of current is sensed, at which point the battery-driven inverter is switched on (in a "continuous" UPS, the output is always from the inverter and the battery is constantly under load while the device maintains its charge and the grid mains is isolated from the connected equipment). The switching is nearly instantaneous, happening in five milliseconds or less, at which point the battery will begin discharging. This state will exist until the UPS senses a return of house power or the unit shuts down to avoid over discharging the battery. Once the unit again is powered by the grid mains, a charging sequence is initiated to bring the battery up to full charge which returns the unit to a back-up stand-by status mode with the house current again passing through to the connected device(s). The important consideration here is any UPS is designed to work with a specific battery chemistry, in this case the AGM lead acid. There are numerous articles available that explain in depth why one should not misuse a charger meant for one type of battery to charge a different battery chemistry. I would advise researching them to at least gain an understanding of what is good practice in this regard and realizing that just because one can does not mean one should. It may result in fewer houses burning down.
@@nikhilatyoutube You're much too modest: It's obvious you don't know anything about lithium ion batteries either. If you choose to use a lead-acid charger with the equalisation mode disabled to charge a lithium-ion battery, then you must disconnect the battery as soon as it is fully charged, to avoid damage to the battery. Best practice is to use the charger meant for the battery. Why someone would say otherwise and put your battery bank at risk is questionable.
I am teasing the idea of running my SMT-750i on lipo with a BMS specifically set to the expected low voltage conditions the Ups wants (luckily I can change them in this unit) but knowing that Lipos don't like to be stored fully charged I am thinking that an extra cell or 2 would help keep the "fully charged" voltage closer to the storage voltage of the cells to increase longevity dramatically. I am still trying to work out a solution that would give me somewhat accurate run-time readouts on the UPS but it's very much a work in progress
There are UPS that has a limit in battery mode but there are that can work continuously. I have a IdealPower UPS that is now serving as an inverter. I just removed the mini speaker.
I replaced lead acid with Lifepo battery . It charging great , great backup. But the problem is that, once the batteries are fully charged . Charging LED doesn't off instead "Replace battery" light is blinking.
I made a 18650 lithium-ion battery for an ultima LCD 2KVA EURO ups The battery was as follows: 30 cell bak high drain 4.2 v 3 A 5. The batteries were placed in 5 columns and 6 rows and thick nickel stripe was used for spot welding. I used BMS 6S.The problem is that in few seconds, not more than a minute, the battery gets extremely hot and smoke begins to appear. Please explain the error.
Looks like you got a nice 3rd degree burn on your finger. Am glad you used the BMS. Not sure how the BMS and the UPS work together on charging. You may consider putting a fuse in place to limit the amp draw as the UPS doesn't appear to have a fan. Have heard that you need to manage the heat output on the UPS to keep it from overheating (because of no fan). Have seen others recommend limiting UPS to 20% of capacity to mitigate heat build up .
you can now buy an exact size LiFephosphate as those in a UPS. will that work as well? I don't have the skills to build a battery cell as u did. thankx.
Hilarious short circuit fire! but this is EXACTLY what I need to do - thankyou and I'll be sure to insulate the terminals. You could easily just add an external, larger battery the same way I expect. Nice work. And Lithium battery voltage is very constant, until it hit's 10% or so left, then it plummets. Lead Acid is a longer curve down.
how many lifepo4? What kind of lifepo4? And what other parts needed to assemble UPS that will last like 6 to 8 hours? Mind sharing a list of things needed? A set up for a computer that have around 500w to 1000w. Thank you!
this one is only 4 ( 32650 cells) because only 4 cells can fit inside the UPS - to build a 12v, you need a BMS. if you need to expand, you can create a parallel connection with additional 4 cells or 8cells connected to the main battery. was able to do this with one of my UPS too. just need to create a small hole to get the wire pass through
Nice Video. Have you experienced any drawbacks of using these LiFePo4 batteries instead of Lead Acid batteries in the last year and a half since you started using it? Thks.
My APC with expanded capacity gives very inaccurate uptime and capacity estimates. However, it seems to only use actual battery voltage to determine state of charge, so automatic shutdown basically works as expected.
Are you sure you did the right thing ?! I think the bms input voltage is exactly 12.6 volts. And in the old battery it is charged between 13.8 and 14 volts. Can't your bms burn or more ?! By the way I thought to put some diodes directly to the ups, and put an external charger of 12.6 volts. I would be happy if you answer me in full detail.
Hmm, I am not sure I agree. From reading about these, the UPS are charging at a lower voltage while the LiFePO4 batteries need at least 14V to be charged properly. This means the new LiFePO4 batteries are under used..never fully charged and can only be used 50% instead of 80% of their capacity.
@@vufirst Thanks for your reply, could you kindly answer me another question please? If I use 1860 cells (no matter how many cells for now) including a suitable BMS, what do you think? Do 3 cells = 3.6X3 or 3.6X4? For UPS of course. (Instead of a 12V battery 7Ah)
You could put a buck converter on it and adjust it to the exact input voltage that your BMS requires. Most BMS allow for some range of input voltages though.
I made a successful DIY Lifepo4 12v 32650 batteries to replace the lead lead acid battery of my APC 800.with 3S BMS of 40A. When tested UPS started with peeps amber lead., where as out put AC voltage is 275 v the.condition of batteries and BMS are normal. May I know the reason for high voltage?
Hello, you can create one for a 24v UPS with 8 batteries, I have the 8 batteries and the BMS lifepo4 8s 24v bms, but I don't know how to make the connections for the bms ???
Replacement of LiFePO4 several Disadvantages:- - 4 cells of LifePO4 required charging voltage of 16.8V while the UPS charged voltage is around 13.5-13.8V. So the full charged capacity could be only less than 80% of LiFePo4 real capacity. - The BMS is passive balancer the balance process will be done only when the charged voltage almost full which it could not possible!
16.8V sounds too high for a LiFePO4 pack. The nominal voltage is only 12.8V, with a recommended charging voltage of 14.4V to 14.6V. I do agree, though, that adding an active balancer would be ideal.
16.8v those are acid batteries like in cars just push around 12v its fine the ups runs or its plug in 24 hours will charge in time blackout usually just happens ones and the capacity seems small
@@richiesalvador9457 I think a proper LiFePO4 charger would be a better option. The batteries won't be in use often so the current BMS has plenty of time to top balance. You would have to isolate the charger from the battery during discharge otherwise it would draw too much current from the charger. A BMS with a separate charge connection would be one way to do it.
@@richiesalvador9457I also made one in 2021 october and it worked like a charm. But suddenly today, it stopped charging and ups doesn't even turn on. I am trying to jumpstart the batteries but they don't even charge. Guess, I have to charge each battery individually?
I have 2 UPS with 12 Volt 5AH Lead Acid Batteries and 12 Volt 7AH Lead Acid Battery, if I buy these Batteries then in the 5AH UPS the 6AH Lithium Batteries will probably undercharge, and in the 7AH UPS the 6AH Lithium Batteries will probably overcharge, what to do and why did not you use the Battery Case ??
@@richiesalvador9457 I see your point. But if the battery(ies) where single 12V like this: www.vmaxtanks.com/V30-800-Deep-Cycle-High-performance-AGM-Battery-_p_46.html Then the UPS charger should charge it correctly you think?
@@KENZIIE_lol correct. It’s just like replacing the orig lead acid battery. No need for BMS. The reason why I use lifepo4 here is because of longer backup time and longer lifespan.
Hi can you do the 24V UPS battery replacement please i will love to see that video as i am planning to do my 24V UPS battery replacement with Lifepo4 battery to.
At the prices the components are currently at for the build, I'm not sure this makes sense. Probably better off going with an external lead acid battery of much higher capacity which could have it's water levels checked. $60-$70 for this (following supplied links and some known pricing) seems pretty high, not to mention the unknown reliability factor of overseas components. I can get a 12 volt utility battery right now for $20 that will plug right in and work - although it will not fit in the case because it's a much larger battery.
Correct. Too many incompatible pieces to fix safely. Pb might be low useable Depth of Discharge and not so great Cycle Life even with very conservative 100-60% DOD but it can be dirt cheap if you shop around and don’t buy new.
You have to change the Macs power down features.. As they are manually set..As APC does not make a PowerChute application that runs on a Mac...Without hacking the through the terminal window..
FYI the actual battery use is only when the power is out. For small drops there will be little demand. Doing a performance test would be interesting to see if the capacity has change. or if the charger circuity was working correctly.
For 2000va 24v ups, How many battery i need and what Amp bms for say almost 500w load for at least 10 min ? Plz answer bro. I have this Power Guard PG-2000VA UPS which has a Display buit in and can hold 4 lead acid battery which is total of 24v 18ah.
@@richiesalvador9457 I ve seen a BMS with contact relay programming. You set charging voltage and over charging voltages from 6v to 60v, do you think it's safe to use that BMS. I am afraid the transistor BMS may short one day and cause fire.
excellent video! only one suggestion: as good as your english is, Lead-Acid is pronounced Led-acid... as Pb in enlish is pronounced "led" not "Leed" otherwise, GREAT! any thoughts on how to increase the capacity limit ie increasing the 1050VA limit?
Regarding the Led vs Lead pronunciation, you're right. My wife already scolded me because of that. haha. I never thought of increasing the capacity. It was just an experiment so I can still use the UPS. But it would be a good idea. I'll see if I can find a way to do it.
Don't forget that if you ever turn your UPS on its end, side or upside down after a couple of days, that masking tape will do nothing to stop your batteries from moving around inside that UPS case.
Yes I would have used 3m VHB double sided tape. I have a 200Ah 12V battery made up of individual 6kg LFP cells and the tape alone is enough to hold them together.
yeah i just ripped the piezo out of mine. I can mute it through software but i just don't want to deal wtih it and mine also tells me the battery remaining through the usb port so i don't really need the buzzer
should add a mppt solar charge controller also to it but . #NOTE make shore it can be programed to the right voltage so not have issues with the ups charger . test the max voltage of the battery at all times to see if it has a equalization charge so you dont blow up the battery / cells. other then that ill hope to see that you made an update of this ups conversion
go to wallmart and get a 105 amp hour deep cell lead acid for about $90 bucks and run that for hours and hours. We have a lot of outages here so I picked up a few of these UPS units for free. people trow them out rather than the hassle of buying a new battery and taring them apart to replace it. They are literally everyplace for free or next to nothing. when the lights go out, your stay on. lead acid can last up to 5 years if you check the water every month. The UPS units charge 24/7 and cook batteries. check water levels and cycle once a month.
From what I have seen, the lead-acid UPS batteries only last 2-3 years and most of them do not hold 80% of the charge after 2 years even though not being used much.
@@vufirst yup. they are battery cookers. you must check the water. walmart sells a deep cycle 100 amp hour. it is called a sealed lead acid but still has caps that unscrew to check water levels . because even sealed will vent off water . especially if just sitting on a needed "trickle charge". unused for 2-3 years. check water, cycle them once a couple month's or so, and use a real battery charger to charge it to full . most throw out ones you can get free, are not "pure sine wave" and not for lithium
No,you can't replace the VRLA batteries with lithium batteries on your existing UPS. Lithium ion batteries have different charging regimes and voltages. If the UPS came with a standard gel type lead acid battery, it will have voltage regulation and charging cycles specific for that type of battery.
I knew something was wrong with the setup.. UPS requires high discharge battery source and PB acid battery allows for really thigh discharge for a short period, while LFP (lifepo5) has significantly lower discharge capacity so you'd need lots of parallels to make it effective.
Thank you so much this is the video I was searching for 1 Since its lead acid battery UPS battery will be continuously charging does battery will destroy or fire due to overcharging 2. This battery capacity is how much AH. Can layman like me try to build battery of course i wont do short like you did And please let me know the how is your battery performance now
Similar scenario is happening to me "My UPS shuts down without warning and Battery BMS goes to OFF mode as well then I have to open UPS reconnect BMS wire only after that my UPS starts". Other than that UPS and Battery are functioning pretty normal.
The LFP (LiFePO4) batteries in this project have a low voltage cutoff of about 2.8v per cell, which is about 11.2v for the pack. Running it that low will shorten the longevity of your battery. If you have a BMS it will protect your battery by cutting it off at a higher voltage like 3v per cell or 12v for the pack. Either way, the UPS inverter which is designed to run on Lead Acid can run down to about 10.8v or even 10v. Its in that voltage range that it is designed to start beeping like crazy to let you know the end is near. With the new batteries, the UPS will never get to that point - thus no warning. There is a solution, cheap. Get a product called a 'screamer' for $2. Search for the term "RC Lipo Battery Low Voltage Alarm". Its used for drones, detects when the cell voltage drops too low and starts beeping like crazy when that happens. It is attached to the "Balance Leads" which are found on all RC batteries. You may have to solder wires into your pack directly. Look for directions on how to do this. Then you can set the desired voltage level, and perhaps stuff the buzzer with some kinda goo or whatever so its not so loud. Set the voltage level to something just above where the BMS will cut it off. Have fun.
Even the smallest ups can consume big currents. The bms will trip on over current protection. Remove the bms and only use a cell balancer. Add a fuse that is twice the rating of battery capacity in ah/hrs. Like if ur battery is 10ah then add a 20 or 15amp fuse. & Remember at 100w load at output will typically result in 120w input or about 10amps in 12v. If r using lifepo4 don't go below 15ah or 20ah..
Just add a reset switch(commonly open) and solder it to the BMS' -B and -P port. You will short it in simple word to revive your BMS. It is the nature of the BMS to cut-off the connection when it reached the lowest voltage settings that is why the current from ac cannot traverse to the battery to restore it and recharge it when the electricity restored. Bore a hole for the reset switch at the back of the ups or on top of it just like mine. Make sure to long press it until you here the tick sound after the long beep to revive it.
DANGER!!!! If your UPS has not started your house on fire yet then it is only because of luck. I just tried the same setup using the same Daly BMS. Mine is a cyberpower pure sine UPS. The problem is the charging circuit is designed for a lead acid profile and it will not charge LiFePO4 batteries correctly. Lead acid chargers are over 14v and the maximum voltage tolerated by LFE batteries is 14.6V but this will SIGNIFICANTLY reduce their lifespan (more than 50%). If you charger runs over 14.6V (different for each UPS) then you run the risk of your battery offgassing to prevent an explosion. Since your charger doesnt realize this happened, it will just keep charging and charging until something catastrophic happens. Your cheap BMS doesnt cutoff the charging soon enough to keep the batteries healthy, it let's you charge then batteries up with the expectation that you are going to use them right away and not let them sit on the charger eternally. Now, here is where your house is at risk of burning down........ when MOSFETs on the BMS fail, they fail open. This means your BMS is no longer protecting your batteries and you will have no idea this happened. There is no alarm, there is no warning whatsoever. Your lead acid charger will just keep charging and charging your LFP batteries until there is a catastrophic failure. These batteries arent as dangerous as LiPo fortunately but you do still risk toxic chemical release offgassing (I dont know what happens when you abuse LFP batteries this bad maybe it is possible to start a fire). In my case with my UPS, it just did not work when I connected fully charged LFP batteries, I suspect the BMS shut off because the lead acid charger was trying to force too many volts- I will test it some more later today. The proper method is to learn how to disable the charge circuit, and connect an external charger that keeps each cell under 3.4V for longevity 3.2V is even better but this isn't a full charge. The external charger can be solar or electric, and it should support LFP battery charging profile. ** The proper way to charge these batteries is with constant current and slowly increasing the voltage as the battery charges **
You can use a diode to block the charger but this will cause some voltage loss. Maybe an Ideal Diode would be a bit more efficient but they will be expensive for most ppl's current draw. For only 120W you can get a 15amp ideal diode for under $30 but the specs on those seems to be false on aliexpress, they cannot handle nearly as much current as promised. Note: MOSFETs in your BMS may last for a couple years, but when they break down your LFP batteries will be instantly in danger.
@@richiesalvador9457 ok, I forgot about the Missus….. If I’d realized that…. I would have sent you an encoded message! :). Good job on both counts, tho! (The video and the missus
You should remember that lifepo4 can only discharge at 1c continuasly and at 2c for few seconds. Using 6000mah cells is a bad idea. Ups will consume more than 15amp if u plug in a 100w load. And a 300w ups can consume upto 30amps. So u should go for 25ah lifepo4 at minimum. Or lithium ion. These batteries will explode or die early if u discharge them so hard..a monitor and pc st idle does not really consume much power. U should have run a cpu and gpu stress test to really see how long the battery takes to puffup😂
@@polized123 yes they are safe and don't catch fire easily but the lifepo4 chemistry does not allow more than 3c or about 18amps in case of a 6ah battery pack for more than 30sec. Any more will shorten the cell life. Recommended discharge rate is 0.2c or about 1.2amps continue. And maximum 1c or about 6amps in this case continuasly. A typical 18650 lithium ion battery can be discharged at 20c or more. But lithium iron phosphate can not be discharged at more than 1c .. and him shorting out the battery by stupidly sticking it in the baremetal case without any protection has already damaged the cells a bit
I did not understand any of the term like 1C 2C, what are these?? If the 12 Volt 6 or 7 AH Lead Acid Battery is there by default then how can the UPS consume more than 15 AMP and why the UPS will consume more than 15 AMP if anyone connects a 12 Volt 6 or 7 AH Lithium Phosphate Battery ??
I know English has a lot of words that are hard to pronounce, Lead is pronounced Led like Led Zeppelin. Thats why they spelt it like that so it wouldn't be pronounced Leed. 😀
Some real schoolboy errors here. I am very surprised you didn't monitor the battery voltages as you tested it to get a better idea of how the unit is treating the cells. You are very lucky you didn't fry the PCB on the second short. I think the only reason you didn't have a VERY serious problem is due to using LiFe Po4 cells. Lucky escape! The UPS is expecting Lead Acid voltages to determine run time and shutoff levels which your BMS is not set to correctly. This whole project is good for a cheap & nasty way to get it to work longer but that's about it.
@@DanielKennedyaeos Not all 25 amps, but bad solder joint will create resistance. even if it eats 2 amps, 25w is a serious heat concentrated in several square mm and will cause sparks and melting
Does this mean the current depends on how much power the device consumes when connected to the ups? If ups only used in a router 9W-18W, then the current drawn from the battery will only be 1.3A-0.67A right?
OMG, just buy F2 connectors... And charging is not "normally" because its very slow, most UPS have 1A current or less and lifepo4 can be charged with 0.5C of full capacity
@@bleeb1347 good for you. I hope you enjoy being annoyed. I never saw him complaining that he was being scrutinized. And no one is forcing you to watch it. Of all the other disgusting garbage on TH-cam/Internet…… 🤦♂️
it's spelled Lead but has two ways of pronounciations and two definitions. you're mispronouncing leed it should be pronounced "LED" lead VS leed. You did an awesome job, just that my ears cringed with wrong pronunciation. Death, dead VS deed, red, read VS reed, read and so on.... my goodness I've become a grumpy 'ol man "time for my meds!"
@@jimbeam5 no, most BMS prevents constant charging. You can measure it with ampere meter, once the batteries are fully charged it cuts off the batteries. Even when you disconnect the whole unit, and connect it again, it checks for the batteries voltage and cuts them off again. My BMS also doesn't respond (starts charging the batteries) even if I use 3-4% of the batteries. It started charging them again when they reached about 90%.
The reason that it drops just suddenly is that LifePo4 cells have a flat discharge curve so all of a sudden one of the cells drops directly from 3.3 volts to 2.5 or less in a matter of seconds this means that it has like 10%-20% capacity left so if one cell drops bellow 2.5 or it may vary due to different BMS's the BMS itself is shutting of the connection to the negative terminal.
U will not hear beeping or anything just will stop suddenly. The other cause is related to the first one if you are running without BMS it will work just fine but if one of the cells drops with 0.7 volts the ups doesn't have time to beep for low voltage.
For example the Lead Acid batteries have a more curved like discharge curve so it will steadily drop from 13 to 12.9 to 12.8 to 12.7 and so on so the ups itself has time to beep.
Cheers and be careful of what you are doing man u almost needed a fire extinguisher !
yep! lesson learned. my first time doing it :)
This
So your advice is to throw away the old ups with faulty battery? I've one.
Na a bucket of sand and an explosion containment pie dish. Then the fire extinguisher.
@@averagestudent4358Just buy a new compatible battery for it. Doesn't cost much.
good choice using LiFePO4 as a replacement. This chemistry is the only viable option when needing a replacement for 12v PB. LiFePO4 has a lower nominal voltage, where other chemistries, such as Li-NCA or Li-NCM, voltage can be too low at 3S or too high at 4S.
I'm wondering how those two short-circuits influenced cells internal resistances. I was once replacing ni-mh cells in old cellphone's battery, and I shorted one cell for good 5-10 seconds. From that point on, this cell had significantly higher resistance than other two. The capacity didn't suffer significantly though.
Just a thought.
Higher ESR will dramatically affect the capacity at high current draw. I assume you tested your shorted cell at a standard rate of 1A which may not show decreased capacity but certainly it will be reduced at higher loads
This is not just an educational video but a motivational as will for he shows his mistake and still take video
The 15 amp BMS at 2:30 will provide only 190 watts or VA (12.7V X 15A).
The speed at which he yanks the pack out, Is nothing but astonishing..
A home computer UPS is a "stand-by" (as opposed to the more expensive "continuous"} power backup. This means that devices connected to it run directly off the grid mains until an interruption of current is sensed, at which point the battery-driven inverter is switched on (in a "continuous" UPS, the output is always from the inverter and the battery is constantly under load while the device maintains its charge and the grid mains is isolated from the connected equipment). The switching is nearly instantaneous, happening in five milliseconds or less, at which point the battery will begin discharging. This state will exist until the UPS senses a return of house power or the unit shuts down to avoid over discharging the battery. Once the unit again is powered by the grid mains, a charging sequence is initiated to bring the battery up to full charge which returns the unit to a back-up stand-by status mode with the house current again passing through to the connected device(s).
The important consideration here is any UPS is designed to work with a specific battery chemistry, in this case the AGM lead acid. There are numerous articles available that explain in depth why one should not misuse a charger meant for one type of battery to charge a different battery chemistry. I would advise researching them to at least gain an understanding of what is good practice in this regard and realizing that just because one can does not mean one should. It may result in fewer houses burning down.
actually charging lithium ion battery with lead acid battery charger is safe. i dont know anything about lifepo4
@@nikhilatyoutube You're much too modest: It's obvious you don't know anything about lithium ion batteries either. If you choose to use a lead-acid charger with the equalisation mode disabled to charge a lithium-ion battery, then you must disconnect the battery as soon as it is fully charged, to avoid damage to the battery. Best practice is to use the charger meant for the battery. Why someone would say otherwise and put your battery bank at risk is questionable.
Bms should protect from over charge and under charge. Over temp under temp.
I am teasing the idea of running my SMT-750i on lipo with a BMS specifically set to the expected low voltage conditions the Ups wants (luckily I can change them in this unit) but knowing that Lipos don't like to be stored fully charged I am thinking that an extra cell or 2 would help keep the "fully charged" voltage closer to the storage voltage of the cells to increase longevity dramatically. I am still trying to work out a solution that would give me somewhat accurate run-time readouts on the UPS but it's very much a work in progress
There are UPS that has a limit in battery mode but there are that can work continuously. I have a IdealPower UPS that is now serving as an inverter. I just removed the mini speaker.
The reason your UPS shutsdown suddenly is because your bms have higher voltage cut off than your ups.
I replaced lead acid with Lifepo battery . It charging great , great backup. But the problem is that, once the batteries are fully charged . Charging LED doesn't off instead "Replace battery" light is blinking.
I made a 18650 lithium-ion battery for an ultima LCD
2KVA EURO ups The battery was as follows: 30 cell bak high drain 4.2 v 3 A 5. The batteries were placed in 5 columns and 6 rows and thick nickel stripe was used for spot welding. I used BMS 6S.The problem is that in few seconds, not more than a minute, the battery gets extremely hot and smoke begins to appear. Please explain the error.
Looks like you got a nice 3rd degree burn on your finger. Am glad you used the BMS. Not sure how the BMS and the UPS work together on charging. You may consider putting a fuse in place to limit the amp draw as the UPS doesn't appear to have a fan. Have heard that you need to manage the heat output on the UPS to keep it from overheating (because of no fan). Have seen others recommend limiting UPS to 20% of capacity to mitigate heat build up .
you can now buy an exact size LiFephosphate as those in a UPS. will that work as well? I don't have the skills to build a battery cell as u did.
thankx.
Can't find those cells or a kit anywhere
Hilarious short circuit fire! but this is EXACTLY what I need to do - thankyou and I'll be sure to insulate the terminals. You could easily just add an external, larger battery the same way I expect. Nice work. And Lithium battery voltage is very constant, until it hit's 10% or so left, then it plummets. Lead Acid is a longer curve down.
Do not use a larger battery than the original because the UPS will overheat as they not designed for continuous use
how many lifepo4? What kind of lifepo4? And what other parts needed to assemble UPS that will last like 6 to 8 hours? Mind sharing a list of things needed? A set up for a computer that have around 500w to 1000w. Thank you!
this one is only 4 ( 32650 cells) because only 4 cells can fit inside the UPS - to build a 12v, you need a BMS. if you need to expand, you can create a parallel connection with additional 4 cells or 8cells connected to the main battery. was able to do this with one of my UPS too. just need to create a small hole to get the wire pass through
@@richiesalvador9457 Thank you so much!
Nice Video.
Have you experienced any drawbacks of using these LiFePo4 batteries instead of Lead Acid batteries in the last year and a half since you started using it? Thks.
still using this setup until now 3+ years.
@@richiesalvador9457 what's the total battery capacity again? and how long does it last during blackout?
So the ups is gonna cut off before bms would cut off huh? Any method to mod ups ?
Will the UPS give a accurate uptime and capacity estimation after replacing the Lifepo4 batts? Vital for UPS with automatic shutdown.
My APC with expanded capacity gives very inaccurate uptime and capacity estimates. However, it seems to only use actual battery voltage to determine state of charge, so automatic shutdown basically works as expected.
Are you sure you did the right thing ?! I think the bms input voltage is exactly 12.6 volts. And in the old battery it is charged between 13.8 and 14 volts. Can't your bms burn or more ?! By the way I thought to put some diodes directly to the ups, and put an external charger of 12.6 volts. I would be happy if you answer me in full detail.
Hmm, I am not sure I agree. From reading about these, the UPS are charging at a lower voltage while the LiFePO4 batteries need at least 14V to be charged properly. This means the new LiFePO4 batteries are under used..never fully charged and can only be used 50% instead of 80% of their capacity.
@@vufirst Thanks for your reply, could you kindly answer me another question please?
If I use 1860 cells (no matter how many cells for now) including a suitable BMS, what do you think? Do 3 cells = 3.6X3 or 3.6X4?
For UPS of course. (Instead of a 12V battery 7Ah)
@@user-zg3nb1mk5b26 4 cels
You could put a buck converter on it and adjust it to the exact input voltage that your BMS requires. Most BMS allow for some range of input voltages though.
@@ooglek The charge wire is the same as the load wire, so it is impossible to use a buck unless you smash the charging circuit out of the UPS
“Charging normally”8:53
Oh boy can’t wait to see where this goes
I made a successful DIY Lifepo4 12v 32650 batteries to replace the lead lead acid battery of my APC 800.with 3S BMS of 40A. When tested UPS started with peeps amber lead., where as out put AC voltage is 275 v the.condition of batteries and BMS are normal. May I know the reason for high voltage?
Hello, you can create one for a 24v UPS with 8 batteries, I have the 8 batteries and the BMS lifepo4 8s 24v bms, but I don't know how to make the connections for the bms ???
Replacement of LiFePO4 several Disadvantages:-
- 4 cells of LifePO4 required charging voltage of 16.8V while the UPS charged voltage is around 13.5-13.8V. So the full charged capacity could be only less than 80% of LiFePo4 real capacity.
- The BMS is passive balancer the balance process will be done only when the charged voltage almost full which it could not possible!
16.8V sounds too high for a LiFePO4 pack. The nominal voltage is only 12.8V, with a recommended charging voltage of 14.4V to 14.6V. I do agree, though, that adding an active balancer would be ideal.
16.8v those are acid batteries like in cars
just push around 12v its fine the ups runs or its plug in 24 hours will charge in time blackout usually just happens ones and the capacity seems small
@@richiesalvador9457 I think a proper LiFePO4 charger would be a better option. The batteries won't be in use often so the current BMS has plenty of time to top balance. You would have to isolate the charger from the battery during discharge otherwise it would draw too much current from the charger. A BMS with a separate charge connection would be one way to do it.
Hello great video could you tell me if you had any problems since you made it
Hi. Is the UPS still holding up?!
yep. still using it til these days.
@@richiesalvador9457I also made one in 2021 october and it worked like a charm. But suddenly today, it stopped charging and ups doesn't even turn on. I am trying to jumpstart the batteries but they don't even charge. Guess, I have to charge each battery individually?
I have 2 UPS with 12 Volt 5AH Lead Acid Batteries and 12 Volt 7AH Lead Acid Battery, if I buy these Batteries then in the 5AH UPS the 6AH Lithium Batteries will probably undercharge, and in the 7AH UPS the 6AH Lithium Batteries will probably overcharge, what to do and why did not you use the Battery Case ??
Honest Question: Doesn't the old case have its own BMS?
No. It was designed for lead acid battery not for lithium
@@richiesalvador9457 How would the case be able to tell since current is current?
@@KENZIIE_lol It does manage a 12v bat but it doesn’t mean it’s able to manage the 3.2v individual cells right? The BMS is for the 4 cells in series.
@@richiesalvador9457 I see your point. But if the battery(ies) where single 12V like this:
www.vmaxtanks.com/V30-800-Deep-Cycle-High-performance-AGM-Battery-_p_46.html
Then the UPS charger should charge it correctly you think?
@@KENZIIE_lol correct. It’s just like replacing the orig lead acid battery. No need for BMS. The reason why I use lifepo4 here is because of longer backup time and longer lifespan.
Hi can you do the 24V UPS battery replacement please i will love to see that video as i am planning to do my 24V UPS battery replacement with Lifepo4 battery to.
Just to help you on your future battery projects, BMS Leads should all have equal lengths.
At the prices the components are currently at for the build, I'm not sure this makes sense. Probably better off going with an external lead acid battery of much higher capacity which could have it's water levels checked. $60-$70 for this (following supplied links and some known pricing) seems pretty high, not to mention the unknown reliability factor of overseas components. I can get a 12 volt utility battery right now for $20 that will plug right in and work - although it will not fit in the case because it's a much larger battery.
Correct. Too many incompatible pieces to fix safely. Pb might be low useable Depth of Discharge and not so great Cycle Life even with very conservative 100-60% DOD but it can be dirt cheap if you shop around and don’t buy new.
You have to change the Macs power down features.. As they are manually set..As APC does not make a PowerChute application that runs on a Mac...Without hacking the through the terminal window..
Hey, going on a year later...is it still working?
yes. im still using it
FYI the actual battery use is only when the power is out. For small drops there will be little demand. Doing a performance test would be interesting to see if the capacity has change. or if the charger circuity was working correctly.
For 2000va 24v ups, How many battery i need and what Amp bms for say almost 500w load for at least 10 min ? Plz answer bro.
I have this Power Guard PG-2000VA UPS which has a Display buit in and can hold 4 lead acid battery which is total of 24v 18ah.
8 cell in series(3.2v each) - 6ah. Your UPS can carry upto 1400watts. So you can add more battery in parallel of up to 50ah.
@@richiesalvador9457 What about BMS ? Which bms i should choose ?
@@Mr.Thanos_ based it on the max ah capacity of your battery build. For 18ah, you can use 20-30ah bms
@@richiesalvador9457 Thnx bro now i get it. Soon I'm gonna do it. If i need any help i will ask you.
@@richiesalvador9457 I ve seen a BMS with contact relay programming. You set charging voltage and over charging voltages from 6v to 60v, do you think it's safe to use that BMS. I am afraid the transistor BMS may short one day and cause fire.
Is there any update on how long it lasts after a full charge?
Still the same until now. 20-25mins with my 21 inch iMac
@@richiesalvador9457 So far no fire or explosions?
@@zeuszaku none so far
@@richiesalvador9457 Have you considered selling one of those with a higher capacity?
@@zeuszaku i’m using it personally. So no plans of selling it
excellent video! only one suggestion: as good as your english is, Lead-Acid is pronounced Led-acid... as Pb in enlish is pronounced "led" not "Leed" otherwise, GREAT! any thoughts on how to increase the capacity limit ie increasing the 1050VA limit?
Regarding the Led vs Lead pronunciation, you're right. My wife already scolded me because of that. haha. I never thought of increasing the capacity. It was just an experiment so I can still use the UPS. But it would be a good idea. I'll see if I can find a way to do it.
What do you mean by "enlish"? 😃😃😃😃, We are more interested in the communication, not here for English class.
Don't forget that if you ever turn your UPS on its end, side or upside down after a couple of days, that masking tape will do nothing to stop your batteries from moving around inside that UPS case.
Yes I would have used 3m VHB double sided tape. I have a 200Ah 12V battery made up of individual 6kg LFP cells and the tape alone is enough to hold them together.
great video....I have lots(15+) apcs that I have to keep replacing the batteries. I think I will try this on the next one that fails.
Go for it! You'll never regret! Mine's still working with 30-40 minutes backup time with my iMac with only 4 32650 batteries.
@@richiesalvador9457 Any overheating issues without a cooling fan for a that running time?
Still working ??@@richiesalvador9457
Keep us updated i want to do that same just not sure it would be safe
Is much more safe to use 4 lithium cells to charge to 12 volts level. No danger from fire and lasting 10 years or more.
@@Landrew0 This has been my concern, does BMS prevent the UPS charging system from destroying the Lithium batteries?
Put an external switch for the speaker.
I might just solder it out next time. Thanks for the tip!
yeah i just ripped the piezo out of mine. I can mute it through software but i just don't want to deal wtih it and mine also tells me the battery remaining through the usb port so i don't really need the buzzer
should add a mppt solar charge controller also to it but . #NOTE make shore it can be programed to the right voltage so not have issues with the ups charger . test the max voltage of the battery at all times to see if it has a equalization charge so you dont blow up the battery / cells. other then that ill hope to see that you made an update of this ups conversion
go to wallmart and get a 105 amp hour deep cell lead acid for about $90 bucks and run that for hours and hours. We have a lot of outages here so I picked up a few of these UPS units for free. people trow them out rather than the hassle of buying a new battery and taring them apart to replace it. They are literally everyplace for free or next to nothing. when the lights go out, your stay on. lead acid can last up to 5 years if you check the water every month. The UPS units charge 24/7 and cook batteries. check water levels and cycle once a month.
From what I have seen, the lead-acid UPS batteries only last 2-3 years and most of them do not hold 80% of the charge after 2 years even though not being used much.
@@vufirst yup. they are battery cookers. you must check the water. walmart sells a deep cycle 100 amp hour. it is called a sealed lead acid but still has caps that unscrew to check water levels . because even sealed will vent off water . especially if just sitting on a needed "trickle charge". unused for 2-3 years.
check water, cycle them once a couple month's or so, and use a real battery charger to charge it to full .
most throw out ones you can get free, are not "pure sine wave" and not for lithium
better with active balancer....ang voltmeter to monitor the voltage of battery....for you to know if it is already low battery ....
No,you can't replace the VRLA batteries with lithium batteries on your existing UPS. Lithium ion batteries have different charging regimes and voltages. If the UPS came with a standard gel type lead acid battery, it will have voltage regulation and charging cycles specific for that type of battery.
He is not using Lithium. He is using Lifepo4 batteries. Which are made for this application..
I knew something was wrong with the setup.. UPS requires high discharge battery source and PB acid battery allows for really thigh discharge for a short period, while LFP (lifepo5) has significantly lower discharge capacity so you'd need lots of parallels to make it effective.
LiFePo4 can have pretty decent discharge rates. 3C to 5C is usually the continuous. I know the 38120 headway cells do quite a bit. Do you need 10C?
UPS won't pull more than 3C continuous and deep cycle lead acid is horrific for high C loads, it won't deliver any capacity.
Thank you so much this is the video I was searching for
1 Since its lead acid battery UPS battery will be continuously charging does battery will destroy or fire due to overcharging
2. This battery capacity is how much AH. Can layman like me try to build battery of course i wont do short like you did
And please let me know the how is your battery performance now
1. The BMS handles the overcharging.
2. 6Ah 12v in series. Battery still performs like the first day i installed it
@@richiesalvador9457 After the battery gets full recharge does the UPS cuts off charging ?
@@Bharani_0601 yes. The BMS has over charging protection
Thank you so much
Similar scenario is happening to me "My UPS shuts down without warning and Battery BMS goes to OFF mode as well then I have to open UPS reconnect BMS wire only after that my UPS starts". Other than that UPS and Battery are functioning pretty normal.
Same thing happened to me. Did you find the solution?
The LFP (LiFePO4) batteries in this project have a low voltage cutoff of about 2.8v per cell, which is about 11.2v for the pack. Running it that low will shorten the longevity of your battery. If you have a BMS it will protect your battery by cutting it off at a higher voltage like 3v per cell or 12v for the pack. Either way, the UPS inverter which is designed to run on Lead Acid can run down to about 10.8v or even 10v. Its in that voltage range that it is designed to start beeping like crazy to let you know the end is near. With the new batteries, the UPS will never get to that point - thus no warning. There is a solution, cheap. Get a product called a 'screamer' for $2. Search for the term "RC Lipo Battery Low Voltage Alarm". Its used for drones, detects when the cell voltage drops too low and starts beeping like crazy when that happens. It is attached to the "Balance Leads" which are found on all RC batteries. You may have to solder wires into your pack directly. Look for directions on how to do this. Then you can set the desired voltage level, and perhaps stuff the buzzer with some kinda goo or whatever so its not so loud. Set the voltage level to something just above where the BMS will cut it off. Have fun.
Even the smallest ups can consume big currents. The bms will trip on over current protection. Remove the bms and only use a cell balancer. Add a fuse that is twice the rating of battery capacity in ah/hrs. Like if ur battery is 10ah then add a 20 or 15amp fuse. & Remember at 100w load at output will typically result in 120w input or about 10amps in 12v. If r using lifepo4 don't go below 15ah or 20ah..
Just add a reset switch(commonly open) and solder it to the BMS' -B and -P port. You will short it in simple word to revive your BMS. It is the nature of the BMS to cut-off the connection when it reached the lowest voltage settings that is why the current from ac cannot traverse to the battery to restore it and recharge it when the electricity restored. Bore a hole for the reset switch at the back of the ups or on top of it just like mine. Make sure to long press it until you here the tick sound after the long beep to revive it.
DANGER!!!! If your UPS has not started your house on fire yet then it is only because of luck. I just tried the same setup using the same Daly BMS. Mine is a cyberpower pure sine UPS. The problem is the charging circuit is designed for a lead acid profile and it will not charge LiFePO4 batteries correctly. Lead acid chargers are over 14v and the maximum voltage tolerated by LFE batteries is 14.6V but this will SIGNIFICANTLY reduce their lifespan (more than 50%). If you charger runs over 14.6V (different for each UPS) then you run the risk of your battery offgassing to prevent an explosion. Since your charger doesnt realize this happened, it will just keep charging and charging until something catastrophic happens. Your cheap BMS doesnt cutoff the charging soon enough to keep the batteries healthy, it let's you charge then batteries up with the expectation that you are going to use them right away and not let them sit on the charger eternally. Now, here is where your house is at risk of burning down........ when MOSFETs on the BMS fail, they fail open. This means your BMS is no longer protecting your batteries and you will have no idea this happened. There is no alarm, there is no warning whatsoever. Your lead acid charger will just keep charging and charging your LFP batteries until there is a catastrophic failure. These batteries arent as dangerous as LiPo fortunately but you do still risk toxic chemical release offgassing (I dont know what happens when you abuse LFP batteries this bad maybe it is possible to start a fire). In my case with my UPS, it just did not work when I connected fully charged LFP batteries, I suspect the BMS shut off because the lead acid charger was trying to force too many volts- I will test it some more later today. The proper method is to learn how to disable the charge circuit, and connect an external charger that keeps each cell under 3.4V for longevity 3.2V is even better but this isn't a full charge. The external charger can be solar or electric, and it should support LFP battery charging profile. ** The proper way to charge these batteries is with constant current and slowly increasing the voltage as the battery charges **
You can use a diode to block the charger but this will cause some voltage loss. Maybe an Ideal Diode would be a bit more efficient but they will be expensive for most ppl's current draw. For only 120W you can get a 15amp ideal diode for under $30 but the specs on those seems to be false on aliexpress, they cannot handle nearly as much current as promised. Note: MOSFETs in your BMS may last for a couple years, but when they break down your LFP batteries will be instantly in danger.
Good explain thank you so much
very cool!
Voltage drop of sharper than lead acid
haha, I hope your wife doesn't watch your TH-cam channel 🤣
Links not expired
just so we are clear "Lead-Acid" refers to the metal LEAD (pronounced LED).
yeah. sorry about my pronunciation. you're correct :)
@@richiesalvador9457 ok, I forgot about the Missus….. If I’d realized that…. I would have sent you an encoded message! :). Good job on both counts, tho! (The video and the missus
You can use plastic bottles coke just cut it
You should remember that lifepo4 can only discharge at 1c continuasly and at 2c for few seconds. Using 6000mah cells is a bad idea. Ups will consume more than 15amp if u plug in a 100w load. And a 300w ups can consume upto 30amps. So u should go for 25ah lifepo4 at minimum. Or lithium ion. These batteries will explode or die early if u discharge them so hard..a monitor and pc st idle does not really consume much power. U should have run a cpu and gpu stress test to really see how long the battery takes to puffup😂
It is a Lifepo4 Battery. It can handle High Discharge Rate. Without getting hot. Plus lifepo4 batteries are very safe. It rarely catch on fire
@@polized123 yes they are safe and don't catch fire easily but the lifepo4 chemistry does not allow more than 3c or about 18amps in case of a 6ah battery pack for more than 30sec. Any more will shorten the cell life. Recommended discharge rate is 0.2c or about 1.2amps continue. And maximum 1c or about 6amps in this case continuasly. A typical 18650 lithium ion battery can be discharged at 20c or more. But lithium iron phosphate can not be discharged at more than 1c .. and him shorting out the battery by stupidly sticking it in the baremetal case without any protection has already damaged the cells a bit
@@KuntalGhosh yeah. That's why they are always configured in parallel. If we need high discharge rate for 12v. The configuration should be. 4s6p
I did not understand any of the term like 1C 2C, what are these??
If the 12 Volt 6 or 7 AH Lead Acid Battery is there by default then how can the UPS consume more than 15 AMP and why the UPS will consume more than 15 AMP if anyone connects a 12 Volt 6 or 7 AH Lithium Phosphate Battery ??
Bms wire should have the same length.
If it smells like BBQ chicken when you're connecting up the batteries... you are doing it wrong. I bet you were awake after that.
Yep. Stupid mistake. I learned from it 🤣
🤣🤣🤣🤣🤣 nice control burnout
I know English has a lot of words that are hard to pronounce, Lead is pronounced Led like Led Zeppelin. Thats why they spelt it like that so it wouldn't be pronounced Leed. 😀
Yes got you
06:57 Fireworks! 🧨
Some real schoolboy errors here. I am very surprised you didn't monitor the battery voltages as you tested it to get a better idea of how the unit is treating the cells. You are very lucky you didn't fry the PCB on the second short. I think the only reason you didn't have a VERY serious problem is due to using LiFe Po4 cells. Lucky escape! The UPS is expecting Lead Acid voltages to determine run time and shutoff levels which your BMS is not set to correctly. This whole project is good for a cheap & nasty way to get it to work longer but that's about it.
300w / 12v = 25 amps, i doubt your soldering will hold that power when UPS will be on battery. More solder wont hurt and be more safe :)
You're not converting all 25 amps to heat.
@@DanielKennedyaeos Not all 25 amps, but bad solder joint will create resistance. even if it eats 2 amps, 25w is a serious heat concentrated in several square mm and will cause sparks and melting
Does this mean the current depends on how much power the device consumes when connected to the ups? If ups only used in a router 9W-18W, then the current drawn from the battery will only be 1.3A-0.67A right?
@@r1ce0919 if battery is 12v then yes
Ups only consumes maximum of 10A. It should not have that problem
Bad idea , the ups does not have the lipo4 charge parameter which is different than lead acid. You don’t know what your doing to the cells ,
i guess it outweighs the benefits. it's been over 3 years and still using this setup.
OMG, just buy F2 connectors... And charging is not "normally" because its very slow, most UPS have 1A current or less and lifepo4 can be charged with 0.5C of full capacity
I’m super surprised no one else is annoyed by how he is pronouncing “lead” as “leed” instead of “led.” No one else?
Nope nobody else cares
@@James0u812 well, it annoys me. If you’re going to make a video public, public scrutiny and criticism is expected.
@@bleeb1347 good for you. I hope you enjoy being annoyed. I never saw him complaining that he was being scrutinized. And no one is forcing you to watch it. Of all the other disgusting garbage on TH-cam/Internet…… 🤦♂️
you gonna burn all that battery and UPS dude ..put a insulator before anything dude for safety
Always take ring off when working with electrical.
You are pronouncing lead wrong.
After 1month of use i can pretty much tell it already exploded
Lol. Fortunately, it’s still working fine until today ;)
@@richiesalvador9457 i have many big ups in my storage idk if they will take lifepo so im researching if it explode or not. Btw thx for the info
I have been using same setup for an Year Now and I'm alive !
BMS will protect it.
pb is pronounced led
it's spelled Lead but has two ways of pronounciations and two definitions. you're mispronouncing leed it should be pronounced "LED" lead VS leed. You did an awesome job, just that my ears cringed with wrong pronunciation. Death, dead VS deed, red, read VS reed, read and so on.... my goodness I've become a grumpy 'ol man "time for my meds!"
Looks extremely dangerous setup.
Dangerous build too
rip that beeper OUT. it is useless. you will know when it is going off.
Umm, how long will it take for the UPS charger to kill the Lithium?
average of 3000 cycle. probably 3-5years. Not sure yet as this is an experiment. With the help of the BMS, hopefully it will last long :)
@@richiesalvador9457 My guess is the constant float charge designed for SLA batteries will greatly reduce the expected life cycle.
@@jimbeam5 the BMS prevents that from happening.
@@adon8672 BMS prevents Over Charging not constant charging.
@@jimbeam5 no, most BMS prevents constant charging. You can measure it with ampere meter, once the batteries are fully charged it cuts off the batteries. Even when you disconnect the whole unit, and connect it again, it checks for the batteries voltage and cuts them off again. My BMS also doesn't respond (starts charging the batteries) even if I use 3-4% of the batteries. It started charging them again when they reached about 90%.