I find it a lot easier to recycle the old battery for about 3 dollars and buy an empty shell that comes with battery holder and a 12 volt balance/charge board for around the same money I get for recycling the old battery. This is a good tutorial for those who want to use the old acid battery.
i have a few of those lead acid batteries that are dead dead dead (one being a literal 80 mv...yeah) i was/am afraid to cut into them since i dont/didnt know how much, if any, battery acid is left in there this video did raise my confidence a little about the acid in there, but still have a few reservations since ive never dealt with something like that
Very nice build, caution on reused/repurposed batteries. Some batteries even though they appear to show good health, might develop short circuit internally, to prevent shorting on the parallel pack, add fuse to each battery for just in case
4S of LiFePO4 batteries would have been much better option, with 3.6 * 4 = 14.4V which is very close to the Alternator/Generator output, and LiFePO4 can tolerate much better operation outside of minimum and maximum voltages without explosive consequences.
Would it have been as cost-effective to build, though? (I have my own concerns with this project-I think I'd have preferred to build a case for the batteries than deal with the lead and the fact that the newly built battery could be mistaken for a common SLA and used improperly…)
@@orppranator5230 Sure but even it it only gets to 14V the batteries will still be at approximately 95%, which in fact will prolong the life of the batteries. There are commercial drop in replacements in LiFEPO4 chemistry to be used in place of Lead Acids. I suspect they don't do any boosting for charging as it will be impractically expensive. In any case having 4.2V max on regular Lithium Ion battery makes this dangerously battery incompatible with alternators/generators/dynamo due to relying on BMC on not letting the batteries go above 4.2V (as with 14V they will be pulled to 4.7V otherwise in 3S configuration). BMC will disconnect the battery from the charging circuit, and in case of the generator charging will cause the system voltage to spike to 18-20V in some cases. This can even happen with solar applications.
for a lead replacement its better to use LFP with a simple active balancer, BMS would disconnect when charging to full and that's very bad, LFP wont explode even at over 4v
@@knghtbrd Lead won't hurt you if you don't eat it or leave it on your skin for days. Believe me, if you build a battery, you won't forget it's a Li-Ion.
Great, yet expensive idea. But could you replace 8 batteries like this in a big UPS and still have the UPS charge them all? How would they also handle deep cycle?
I would have wired in a balance lead so you could use the smart charger to charge the battery. Just trusting a fit and forget BMS is likely to cause issues if/when it fails.
just order a 3d printed box and put 2 metal screws outside for the positive and negative to avoid all that work. 3D printed boxes aren't so expensive. Other than that, good work mate. Also i am wondering. Those batteries are like 14.4V at full charge. Now by puting lipo 3.7V inside in a series, that means if you are fully charge those batteries the voltage will be 4.2V * 3 = 12.6V. also the minimum voltage is 3.3V * 3 = 9.9V. That means you can't have the batteries less than 30-40% of capacity to get a 12V device fully working without any issues. Am i thinking it in a wrong way ?
yeah whats the point in using case of a dead battery that makes up 5% of the battery and replace the other 95% at that point you're just making more work for yourself while creating a hazardous mess.
@@darkshadowsx5949 It looks cool and is sturdy. For some people (myself included) that's worth it. The lead should be properly recycled anyway, so yes it's (extremely) hazardous, but could be handled properly by someone who knows what they're doing
If this batteries would be available for sale I would be buying to replace those darn UPS batteries. Also, would be great if he can do the same type for motorcycle batteries style, bikers would also be buying those.
The case is made for SLA, which is heavy and swells up. Li-Ion is light and strong and doesn't really need a protective case. It's mostly to protect the wires, mount the hardware, and to look nice.
Should you use batteries that are below a certain voltage? Nice build & neat mini spot welder! Not sure if you did, but it would be a good idea to use a chemical cleaner that can neutralize any remaining battery acid residue.
Just rinse with a dilute solution of bicarbonate of soda to neutralise any acid, then rinse with plain water. What you must do is make sure all the batteries in a single parallel set are near to the same voltage, to prevent potential damage from the heavy current which would flow if they were connected together in very different charge states.
Connecting cells in parallel like that with no fusible links is monumentally stupid. That battery is a fire waiting to happen. If one cell in there starts to fail shorted, it will rapidly deteriorate to a full short with all other cells in parallel discharging through it. Since all cells are in close proximity, the lot will go up in flames, violently. The correct method is to connect one side of the parallel cells (usually the positive) to a bus bar with fusible wire. That way, if a cell fails the fusible link to that cell will break isolating it from the rest and preventing a disaster.
For a small 7ah replacement pack like this, it's probably fine. But in general I couldn't agree with you more. Blows my mind how this plastic cell holder and nickel strip method is still the "de facto" way for building lithium packs of various sizes, even in the homebrew powerwall space, where hundreds upon hundreds of cells are combined into a single pack in this way. Besides for just the safety hazard, it seems like any kind of cell-level maintenance is bound to be a total nightmare as you basically need to tear the whole pack apart in its entirety in order to get the cells isolated for testing. Who wants to sit there stripping welded nickel when conventional battery spring mechanisms could be used instead? I have thousands of 18650's waiting to be put into packs, and this is where I've stalled with my build. I'm trying to find a better way to build packs as I refuse to use the same holder+nickel strips method that everyone else is using. I believe there is a far better way to assemble packs that is not only easier and cheaper to do, but also much more future proof. the problem is, I haven't been able to figure out exactly what that is, or find anyone who's come up with a good enough or easily approachable/DIY design. You either need a 3d printer, or to buy expensive parts, for instance. Meanwhile raw materials like sheet wood/plastic are readily available for cheap... Someone just needs to think out of the box and come up with a better design rather than everyone being a copycat of something that's frankly awful.
@@DimitriPappas you are 100% right in what you say, there are hundreds of videos on YT with the same method of building this 12V 14Ah or 16Ah or 20Ah etc... with just a simple BMS and no other protection. Did you find a better method, what is your progress... i'd like to see someone building something better and safer and easier to repair..
@DimitriPappas legend says that you after 2 year's still waiting with thousands batteries with better way to connect them lmaooo I always hated "smart people" like you and that Ainstain above it 😂😂😂
Is it worth it to rebuild a battery about half the size of that one? Its for a kind of video camera. Thank you 🤓 is there a video that helps to figure out the 18650 (or similar) configuration, voltage conversions, amp hours, charging conditions,...etc? Thank you 🤓
From experience - cells who was lower than 2.5V some period, at charging gets hotter than normal cells because of internal resistance and change in chemistry.. That after few cycles can't allow to charge battery pack completely, degradating good cells. However, at discharge or at standalone, they create parasitic discharge for good cells.. 😉 That's why I never reuse cells again with starting voltage below 2.9-3V after old pack disassembly.. But basic idea is good and great job, only few cells were bad..
Fantastic work, dude! Nicely done! 😃 You could've closed it with screws, but well... That works as well. 😊 Anyway, stay safe there with your family! 🖖😊
It's a good idea. However, if you use this modified battery in a device that usually uses Lead Acid batteries, I guess you will have issues with the charging cycle and voltages? Will the BMS be enough to overcome the differences?
A problem I see is that those cell have a nominal voltage of 3.6V so very quickly after even partial discharge, you will have closer to 10.8V, not 12.6V. This is a problem already for devices such as a UPS that normally takes an AGM type battery. You would likely get a warning (beeps) at or close to 10.8V, when the lithium-ion cells are still in a high state of charge. Other 12V devices might also "complain" that they are being undervolted. What these would be good for is a 36V UPS (and/or a 36V electric scooter). Then you can use a 10S configuration (36V nominal), and then just don't charge them all the way up (to 10 * 4.2V = 42V). You really need 3 1/3S to get a nominal voltage of 12V so unfortunately, this application is far from ideal. Also, by the time you buy all new cells and a BMS, it will be close to the price of an already made battery of this type, so you are doing all of that labor for "nothing", plus making a mess and a hazard.
Not to mention, you're not figuring in the cost of his spot welder. If you do not have one that will cost another $100+. But hey, he already had the stuff and was using recycled batteries so HIS cost was minimal. I think I'd rather buy or use something else for the box than go through that recycling nightmare. Sometimes it's just not worth the effort. You're right about the voltages also, it wouldn't work right with 12 volt stuff.
@@VERYMADSTUDIOS That is certainly possible, but I stated usable on a 36V UPS. I didn't say it would work on a 12V UPS. In fact I said it is a problem.
I'm thinking what if you had used 4 cells in series, so the cells never get to full charge off a vehicle charging system but always stays around the maximum charge available. So you would have batteries capable of reaching 16.8 volts but never going past 14volts from the vehicles charging system. The lipo 18650s still put out a lot of amps at a lower charged rate, not full capacity but that would be offset by the paralleled amperage capacity. So the lipo 18650s would deliver a big punch at lower voltage, and the bike would only charge them up to around 14 volts making them safe for continuous charging. The only problem I see is if the charge system fails you could end up with a huge dump of voltage into the battery, unlike with lead acid the battery could go bang.
Interesting. But I would expect higher capacity, not just 9Ah to 14Ah increase :) Is it safe to use this in UPS instead of lead-acid one? There is charging circuitry for lead-acid battery in UPS, will it work OK with this converted battery?
@@Görkem-x5h But he installed a BMS in the battery, right? Would he have to take the lead battery BMS out? I don't understand the math of 21 cells with 2000 mAh not adding up to 42,000 mAh . Is it the number of cells in parallel that determines the capacity?
Why not we use the battery pack made with the lithium ion batteries with the charge output of the main unit wherein We get 15.18 volt DC ? Why you require the balanced charge/discharge unit seperately for charging? Please explain.
Lithium ion batteries require a BMS (battery management system) to keep the cells balanced, and to avoid over charging or over discharging. A BMS becomes critical when the original equipment was designed for a different battery technology. #1: If you only look at the overall voltage a few years of use can result in aging drift. That is some groups of cells may charge to a higher voltage than others. Example: 4+4+4=12v and 3.5+4+4.5=12v too, but the second example over-charges one of the cell groups. The higher the voltage the fewer charge/discharge cycles you get----to the point that limiting charge to 80% of rated capacity will give you 3 to 4 times as many charge/discharge cycles (a trick some systems designed for lithium batteries follow when battery life is a higher priority than battery capacity). A decent BMS will keep the voltages of each section of the battery perfectly in balance with other sections. #2: AGM (absorbed glass mat) lead-acid batteries (or any lead-acid battery) loves to be trickle charged. But trickle charging any lithium battery will destroy it, and in the case of lithium ion might cause a fire. A BMS will cut off charging a fully charged battery system, even though the equipment the battery is installed into wants to trickle charge it. #3: Over discharging a lithium battery is bad and can drastically shorten the life of the cells or even kill them. This is also true for lead-acid, but if equipment is designed for lead-acid, its low cut-off voltage will be different than what a lithium battery needs. A BMS will disconnect the battery when it senses the cell voltages have fallen too low. If the equipment happens to cut off discharge at a higher voltage then the BMS, no harm, no foul (but you don't get the full capacity of lithium). Food for thought: Lithium iron phosphate (LFP or LiFePO4) would be a better choice than lithium ion for an application where a little more weight and size is worth the added safety of not being a fire hazard. For example a kid's toy car or scooter, or something like a UPS (uninterruptible power supply). For a laptop, a phone, or a car, the size vs capacity tradeoff is often worth the trouble of the added safety systems. Note that the working voltage of LFP cells is lower than lithium ion, so a different BMS is needed, but you still need one. Also, if your equipment needs more than one lead-acid battery in series for a higher voltage, it'd be best if your lithium replacement's BMS could see across the whole string of cells. Example: a typical smallish UPS will use two lead-acid AGM batteries and work at 24 volts. So best to build a single replacement lithium battery that is the physical size of two of the original batteries, with a single BMS that looks across the full 24 volts of lithium cells. See point #1 for why.
@@ScottyDMcom Thank you so much that you have taken pains in highlighting me on charging and the need of the BMS in lithium based cells. From the explanation I could get that the lithium based cells require proper charging voltage and the charging is not dependant on the how much current goes in to battery pack. Am I right in this understanding? Please correct me if not?
I was wondering the same thing. I tried different lead acid brands and they seem to last 3 years tops. Seem even a NINH thing that can work for a few seconds would even be a great idea.
Presumably you did this for fun, because there is absolutely no way that it is cost effective. Where the volume and weight are not an issue (like my garden shed full of solar-charged-backup batteries) sealed lead acid are far safer, miles cheaper and require almost no management electronics (just a standard charge controller). AND my shed hasn't burst into flames yet.
the BMS has a balance ic, the chip use resistors to drop the battery voltage when pass 4,2v, and stop discharging the cell at ~4,19v, so it's necessary to charge the pack a little bit more than 12,60v, like 12,65, 12,70...
I use an led as indicator for each cell, the led (with current limiting resistor) is in parallel with the big resistor, so I know when the BMS is balancing and which cell get charged first...
The parallel connected cells are forced to remain at the same voltage as each other by the simple fact that they're all connected. The circuit handles balancing each set of parallel cells with the other sets.
7:06 "twice less" ← i can finally interpret this correctly, because of the scale. It's supposed to mean "half" - in this context "it weighs less than half". I've noticed this phrase on the Kreosan (English) channel, a few years ago, but wasn't quite sure what it actually meant.
I got a new battery for my electric bike it’s a 36 volt 14 amp battery but when I ride around or going over bumps it cuts off like it’s shorting out I think something in the battery pack is loose or something how would I fix that
I noticed that you charged the completed battery on a (Li-Po) setting rather than (Li-ion) Is this safe to do so? your charger is capable of (Li-ion) charging.
@@MrDexi87 wouldn't it be irrelevant which Lithium setting it's charged with, as long as the whole pack isn't over-volted? I mean could this pack be used (and charged) like an SLA Pb battery? That's why there's a BMS, right?
@@fluffyfloof9267 true , but if u charge 1s with 4.1v max voltage u can increase battery life, that's why imax b6 using lower voltage for charging li-ion cells ...
@@fluffyfloof9267 I'd like to know this as well. BMS's generally seem pretty straightforward in their operation, except when it comes to charging the cells properly once everything is assembled. This video was basically the first example I've seen where the creator actually touched on this area but still I have some unanswered questions... Like do these cheap BMS's disconnect charge when input voltage exceeds the lipo voltage ratings? What is the safe charge voltage and amp range for a 3S7P pack with a bms like the one in this video attached to it? I realise that depends on the cell specifications but in general (assuming mixed cells) what would be an average safe range for such a battery? And just as importantly, what WOULD HAPPEN if you used one of these batteries as an SLA replacement in a typical standby 300-600W UPS, for instance? Would it be safe? If not, why not? If someone says it's a 3S Li-Ion battery and therefore lower nominal voltage than the SLA it's replacing, that doesn't really explain why it's not suitable. We know that most UPS's will cut out at around 10.5v and charge up to max of around 15v. if the BMS can cut off charge at appropriate times (10.5v - 12.6v = 3.5v - 4.2v per cell, respectively) then there should still be an overlap range of compatibility even if its not a perfect match, yeah ? As far as I can see, all it means is that the cells will never fully discharge further than 3.5v, which is a good thing because it means way more use cycles. Sure you won't get the full 14ah of capacity, but even if you get the 7-9ah of the original SLA battery, it seems like a win
Bro you need to dyor, the world isnt here to answer questions and if they answered that question, you would have a million more. Go learn stuff and be an adult
Could I insert these directly into a desktop UPS (230V AC, 2kVA, 1.2kW, 2x12V9Ah lead acid batteries)? My intuition tells me it should be fine, as long as the LiPo cells can draw sufficient current (for 2Ah cells, that would be a C-rating of at least 2000/24/7/2=6), and since the charge voltage of lead-acid batteries is typically 12.7V or less, but I prefer to be safe than sorry and double check this. Understandably, the UPS datasheet doesn't provide information on internal charging circuitry, so I'm not sure how to proceed safely.
Excelente proyecto muy bien desarrollado y mejor ejecutado , gracias por compartir sus conocimientos y experiencias , un saludo cordial y por supuesto un gran like desde Narón , Galicia ( España) 🤓 😜
could someone help me. so i have made one of these battery but not to sure on how to charge it and i dont have a balance charger. any ideas would be gratefull.
@@Bob_Adkins That's what I was thinking. The BMS is built into the battery in this design so it should be alright. The main thing is the estimated time on battery and battery percentage probably won't be accurate and I'm not sure you could calibrate it given the differences in voltage drop between Li-ion and lead acid. That could complicate things for controlled shutdowns when the UPS gets to a certain battery level/time remaining.
@@your_new_sjw_waifu Yeah, if your UPS reports battery condition, it will be inaccurate but you can mentally compensate. I think it's worth it, lead-acid batteries are awful, last only 2 years for me. The LA batteries can also show a false voltage, they check 12-13v but when power trips they only last a minute. Load testing twice a year is a headache. Li-Ion is usually good if the voltage is good, and should last many years if kept at 4.0v per cell. Li-Ion doesn't like to be stored at maximum voltage (4.2).
@@Bob_Adkins Yeah, I could mentally compensate but I couldn't have my computer reliably shut down and turn the PSU off when battery level reached 5% or there's 5 minutes remaining (whichever comes first). Risk of unclean poweroffs really defeats most of what makes a PSU worth it to begin with.
@@your_new_sjw_waifu Your concerns are real, it's not a perfect solution. Someone should make a BMS that will make the battery voltage correct, and act just like a LA battery.
Ignoring the voltage discrepancy using 3 in series instead of four, those 21 18650s would cost over $80, while the lead acid would cost $25 to $30. Even using 15 to more closely match the 9Ah would cost $45 to$50. Plus if you had it in an application where it’s charged by a source who’s voltage varies, like an alternator, you would need regulator circuitry to make sure the lithium batteries don’t get over-voltage and wind up burning down whatever you put them in. The real question is why would you even do something like this? The one benefit lithium has over lead acid is energy density. So unless it’s for a portable application, you’re spending 2.5 - 3 times as much for no benefit.
One serious issue with these lead acid batteries is that they often fail prematurely over winter. Lithium ion cells can survive cold winters. This size battery is used in golf carts and lawnmowers which are stored over winter.
Right. the lead acid battery is about $20-30, but lithium batteries in the same size as the lead acid battery are almost triple that, but worth paying for due to the higher number of recharge cycles per dollar, and because the spot welder alone costs over $50. I doubt I'll use the spot welder for anything else and finding defective" power drill batteries with an average cost of $0.80 per cell isn't something I do well. I've begun to establish limits to the things I want to DIY. And you gotta love the disclaimer at the bottom of this video's description!
This is cool but I made a 3s10p 12.6v li-ion battery and I've got no idea what to do with it. I was originally going to use it as a camping battery in my car but I don't think you can charge it with an alternator as the voltage is too high ~14.4v. So I have a 12.6v charger but it plugs into AC power so if I wanted to use it in the car, I could hook up my inverter to the car battery and this charger to the battery, no problem. But now I have the additional problem of powering things with the 3s battery, because its voltage is too low to consistently power an inverter. The nominal charge of the battery is not 12.6v but 11.1v (3.7x3) and won't work for an inverter. Honestly can anyone tell me what a 3s battery is good for?
Hope you disposed of the lead properly so that it can get recycled. Overall you'd have been better off just putting the lithium battery into a new box in my view.
not sure if your aware but this video was stolen and posted to facebook by one of those fake diy channels. they also replaced the original audio with a voiceover to avoid content matches.
The long ones connect each row of seven batteries in parallel. The short jumpers connect the rows in series. Without the short jumpers, each row doesn't produce 12 volts. That's the limit of my electrical knowledge.
The idea of using multiple jumpers is to share the load across several connections. In theory you could just use a single link to connect each parallel set in series, but using multiple links allows them all to share the load and run cooler.
I find it a lot easier to recycle the old battery for about 3 dollars and buy an empty shell that comes with battery holder and a 12 volt balance/charge board for around the same money I get for recycling the old battery. This is a good tutorial for those who want to use the old acid battery.
Very nice build. I recently bought a 12v box kit but your reuse of an old lead acid is perfect!
i have a few of those lead acid batteries that are dead dead dead (one being a literal 80 mv...yeah)
i was/am afraid to cut into them since i dont/didnt know how much, if any, battery acid is left in there
this video did raise my confidence a little about the acid in there, but still have a few reservations since ive never dealt with something like that
Nice work! I would like to know more about your spot welder. Is it something you made? If so are there plans for it or a video?
Link for the welder is in the video info
Explained it nicely I do hope any who are interested can convert their Lead acid Battery to Lithium ion Battery easily.
I would have purchased a new case, but other than that, this is exceptional work.
Why purchase a new case (if indeed you can) when you can get an old one for nothing?
@@juliocosta5818 - Because of all the mess and time wasted dealing with lead cells?
Purchasing lifeo4 versions of gel cell batteries would be my first choice. And I build many battery packs.
Very nice build, caution on reused/repurposed batteries. Some batteries even though they appear to show good health, might develop short circuit internally, to prevent shorting on the parallel pack, add fuse to each battery for just in case
4S of LiFePO4 batteries would have been much better option, with 3.6 * 4 = 14.4V which is very close to the Alternator/Generator output, and LiFePO4 can tolerate much better operation outside of minimum and maximum voltages without explosive consequences.
Would it have been as cost-effective to build, though? (I have my own concerns with this project-I think I'd have preferred to build a case for the batteries than deal with the lead and the fact that the newly built battery could be mistaken for a common SLA and used improperly…)
You need the alternator to be higher than the battery, so that it can charge the battery to full.
@@orppranator5230 Sure but even it it only gets to 14V the batteries will still be at approximately 95%, which in fact will prolong the life of the batteries. There are commercial drop in replacements in LiFEPO4 chemistry to be used in place of Lead Acids. I suspect they don't do any boosting for charging as it will be impractically expensive.
In any case having 4.2V max on regular Lithium Ion battery makes this dangerously battery incompatible with alternators/generators/dynamo due to relying on BMC on not letting the batteries go above 4.2V (as with 14V they will be pulled to 4.7V otherwise in 3S configuration). BMC will disconnect the battery from the charging circuit, and in case of the generator charging will cause the system voltage to spike to 18-20V in some cases. This can even happen with solar applications.
for a lead replacement its better to use LFP with a simple active balancer, BMS would disconnect when charging to full and that's very bad, LFP wont explode even at over 4v
@@knghtbrd Lead won't hurt you if you don't eat it or leave it on your skin for days. Believe me, if you build a battery, you won't forget it's a Li-Ion.
Great, yet expensive idea.
But could you replace 8 batteries like this in a big UPS and still have the UPS charge them all?
How would they also handle deep cycle?
I would have wired in a balance lead so you could use the smart charger to charge the battery. Just trusting a fit and forget BMS is likely to cause issues if/when it fails.
just order a 3d printed box and put 2 metal screws outside for the positive and negative to avoid all that work.
3D printed boxes aren't so expensive.
Other than that, good work mate.
Also i am wondering. Those batteries are like 14.4V at full charge. Now by puting lipo 3.7V inside in a series, that means if you are fully charge those batteries the voltage will be 4.2V * 3 = 12.6V.
also the minimum voltage is 3.3V * 3 = 9.9V. That means you can't have the batteries less than 30-40% of capacity to get a 12V device fully working without any issues.
Am i thinking it in a wrong way ?
yeah whats the point in using case of a dead battery that makes up 5% of the battery and replace the other 95%
at that point you're just making more work for yourself while creating a hazardous mess.
@@darkshadowsx5949 It looks cool and is sturdy. For some people (myself included) that's worth it. The lead should be properly recycled anyway, so yes it's (extremely) hazardous, but could be handled properly by someone who knows what they're doing
If this batteries would be available for sale I would be buying to replace those darn UPS batteries. Also, would be great if he can do the same type for motorcycle batteries style, bikers would also be buying those.
Interesting project, thanks for sharing your experiment. Removing all the internal bracing reduces the structural strength of the casing.
The case is made for SLA, which is heavy and swells up. Li-Ion is light and strong and doesn't really need a protective case. It's mostly to protect the wires, mount the hardware, and to look nice.
Does the BMS give the charge curve for the Lifepo4 battery? Or is it necessary a specific regulator from alternator to the battery?
Nice work with the chisel.
You briefly mentioned building one of a higher capacity, say 12V and 150 amps. Where can I find how to do this? Thanks!
GOOD, SIR YOU HAVE GIVEN CLEAR CONCEPT ABOUT 3S PACK
Nice video, thanks. Could you make one for an auto battery replacement?
Should you use batteries that are below a certain voltage? Nice build & neat mini spot welder! Not sure if you did, but it would be a good idea to use a chemical cleaner that can neutralize any remaining battery acid residue.
Just rinse with a dilute solution of bicarbonate of soda to neutralise any acid, then rinse with plain water.
What you must do is make sure all the batteries in a single parallel set are near to the same voltage, to prevent potential damage from the heavy current which would flow if they were connected together in very different charge states.
@@melkiorwiseman5234 that makes sense! Thank you 🤓
Connecting cells in parallel like that with no fusible links is monumentally stupid. That battery is a fire waiting to happen. If one cell in there starts to fail shorted, it will rapidly deteriorate to a full short with all other cells in parallel discharging through it. Since all cells are in close proximity, the lot will go up in flames, violently. The correct method is to connect one side of the parallel cells (usually the positive) to a bus bar with fusible wire. That way, if a cell fails the fusible link to that cell will break isolating it from the rest and preventing a disaster.
For a small 7ah replacement pack like this, it's probably fine. But in general I couldn't agree with you more. Blows my mind how this plastic cell holder and nickel strip method is still the "de facto" way for building lithium packs of various sizes, even in the homebrew powerwall space, where hundreds upon hundreds of cells are combined into a single pack in this way. Besides for just the safety hazard, it seems like any kind of cell-level maintenance is bound to be a total nightmare as you basically need to tear the whole pack apart in its entirety in order to get the cells isolated for testing. Who wants to sit there stripping welded nickel when conventional battery spring mechanisms could be used instead? I have thousands of 18650's waiting to be put into packs, and this is where I've stalled with my build. I'm trying to find a better way to build packs as I refuse to use the same holder+nickel strips method that everyone else is using. I believe there is a far better way to assemble packs that is not only easier and cheaper to do, but also much more future proof. the problem is, I haven't been able to figure out exactly what that is, or find anyone who's come up with a good enough or easily approachable/DIY design. You either need a 3d printer, or to buy expensive parts, for instance. Meanwhile raw materials like sheet wood/plastic are readily available for cheap... Someone just needs to think out of the box and come up with a better design rather than everyone being a copycat of something that's frankly awful.
Very professional looking job
Great 👍
@@DimitriPappas you are 100% right in what you say, there are hundreds of videos on YT with the same method of building this 12V 14Ah or 16Ah or 20Ah etc... with just a simple BMS and no other protection.
Did you find a better method, what is your progress... i'd like to see someone building something better and safer and easier to repair..
@DimitriPappas legend says that you after 2 year's still waiting with thousands batteries with better way to connect them lmaooo
I always hated "smart people" like you and that Ainstain above it 😂😂😂
@@soulbrothers7789 I understand, ignorance is usually accompanied by anger and hatred.
Is it worth it to rebuild a battery about half the size of that one? Its for a kind of video camera. Thank you 🤓 is there a video that helps to figure out the 18650 (or similar) configuration, voltage conversions, amp hours, charging conditions,...etc? Thank you 🤓
The most important thing - the 3D printed cell holder - is missing in the links :)
From experience - cells who was lower than 2.5V some period, at charging gets hotter than normal cells because of internal resistance and change in chemistry.. That after few cycles can't allow to charge battery pack completely, degradating good cells. However, at discharge or at standalone, they create parasitic discharge for good cells.. 😉
That's why I never reuse cells again with starting voltage below 2.9-3V after old pack disassembly..
But basic idea is good and great job, only few cells were bad..
Fantastic work, dude! Nicely done! 😃
You could've closed it with screws, but well... That works as well. 😊
Anyway, stay safe there with your family! 🖖😊
The plastic base isnt thick enough for screws, anyway the glue seals it from water getting in.
Awesome build. Simple and sturdy. 👍
It's a good idea. However, if you use this modified battery in a device that usually uses Lead Acid batteries, I guess you will have issues with the charging cycle and voltages? Will the BMS be enough to overcome the differences?
This is by the best video I have ever seen
A problem I see is that those cell have a nominal voltage of 3.6V so very quickly after even partial discharge, you will have closer to 10.8V, not 12.6V. This is a problem already for devices such as a UPS that normally takes an AGM type battery. You would likely get a warning (beeps) at or close to 10.8V, when the lithium-ion cells are still in a high state of charge. Other 12V devices might also "complain" that they are being undervolted. What these would be good for is a 36V UPS (and/or a 36V electric scooter). Then you can use a 10S configuration (36V nominal), and then just don't charge them all the way up (to 10 * 4.2V = 42V). You really need 3 1/3S to get a nominal voltage of 12V so unfortunately, this application is far from ideal. Also, by the time you buy all new cells and a BMS, it will be close to the price of an already made battery of this type, so you are doing all of that labor for "nothing", plus making a mess and a hazard.
Yeah, for 12v you need 4 3.2v Lifepo4 cells
Not to mention, you're not figuring in the cost of his spot welder. If you do not have one that will cost another $100+. But hey, he already had the stuff and was using recycled batteries so HIS cost was minimal. I think I'd rather buy or use something else for the box than go through that recycling nightmare. Sometimes it's just not worth the effort. You're right about the voltages also, it wouldn't work right with 12 volt stuff.
This battery would not be usable on a UPS, unless one would figure out a way to charge it with 12.6 volt constant voltage...
@@VERYMADSTUDIOS That is certainly possible, but I stated usable on a 36V UPS. I didn't say it would work on a 12V UPS. In fact I said it is a problem.
but sometimes guys its fun making some diy stuff than buying a perfect battery(i just told my thought pls dont be rude to me)😁
Nice work. I'm working on one from a kit right now. Thanks
Which camera you used?
How to shoot?
I’ll remember to drain the wolts thx
out of these 2 environmental killers which would you choose??????????????????????????????????????????
can these converted lithium ion battery be used to motorcycle scooters?
nice build!
Isn’t the old lead in those batteries dangerous?
Can you put these in series to make ~24v?
Any problem we use a 12 v li-ion battery charger in the case of balanced charging unit
how about the heat dissipated by the bms and battery? will it be a concern since its sealed inside?
I'm thinking what if you had used 4 cells in series, so the cells never get to full charge off a vehicle charging system but always stays around the maximum charge available.
So you would have batteries capable of reaching 16.8 volts but never going past 14volts from the vehicles charging system.
The lipo 18650s still put out a lot of amps at a lower charged rate, not full capacity but that would be offset by the paralleled amperage capacity.
So the lipo 18650s would deliver a big punch at lower voltage, and the bike would only charge them up to around 14 volts making them safe for continuous charging.
The only problem I see is if the charge system fails you could end up with a huge dump of voltage into the battery, unlike with lead acid the battery could go bang.
Interesting. But I would expect higher capacity, not just 9Ah to 14Ah increase :) Is it safe to use this in UPS instead of lead-acid one? There is charging circuitry for lead-acid battery in UPS, will it work OK with this converted battery?
No. Lead cells and lithium cells have different minimum voltage and maximum voltage so it is not recomended.
@@Görkem-x5h ... 🤔 ... BMS is made for that .....
@@yvonf2312 you need different bms. A bms made for lead cells won't work on lithium cells.
@@Görkem-x5h But he installed a BMS in the battery, right? Would he have to take the lead battery BMS out?
I don't understand the math of 21 cells with 2000 mAh not adding up to 42,000 mAh . Is it the number of cells in parallel that determines the capacity?
@@paddlepower888 to get 12 V you need to add 3 banks of paralel lithium cells in series. Series connections don't add up on capacity but voltage.
Why not we use the battery pack made with the lithium ion batteries with the charge output of the main unit wherein We get 15.18 volt DC ? Why you require the balanced charge/discharge unit seperately for charging? Please explain.
Lithium ion batteries require a BMS (battery management system) to keep the cells balanced, and to avoid over charging or over discharging. A BMS becomes critical when the original equipment was designed for a different battery technology.
#1: If you only look at the overall voltage a few years of use can result in aging drift. That is some groups of cells may charge to a higher voltage than others. Example: 4+4+4=12v and 3.5+4+4.5=12v too, but the second example over-charges one of the cell groups. The higher the voltage the fewer charge/discharge cycles you get----to the point that limiting charge to 80% of rated capacity will give you 3 to 4 times as many charge/discharge cycles (a trick some systems designed for lithium batteries follow when battery life is a higher priority than battery capacity). A decent BMS will keep the voltages of each section of the battery perfectly in balance with other sections.
#2: AGM (absorbed glass mat) lead-acid batteries (or any lead-acid battery) loves to be trickle charged. But trickle charging any lithium battery will destroy it, and in the case of lithium ion might cause a fire. A BMS will cut off charging a fully charged battery system, even though the equipment the battery is installed into wants to trickle charge it.
#3: Over discharging a lithium battery is bad and can drastically shorten the life of the cells or even kill them. This is also true for lead-acid, but if equipment is designed for lead-acid, its low cut-off voltage will be different than what a lithium battery needs. A BMS will disconnect the battery when it senses the cell voltages have fallen too low. If the equipment happens to cut off discharge at a higher voltage then the BMS, no harm, no foul (but you don't get the full capacity of lithium).
Food for thought: Lithium iron phosphate (LFP or LiFePO4) would be a better choice than lithium ion for an application where a little more weight and size is worth the added safety of not being a fire hazard. For example a kid's toy car or scooter, or something like a UPS (uninterruptible power supply). For a laptop, a phone, or a car, the size vs capacity tradeoff is often worth the trouble of the added safety systems. Note that the working voltage of LFP cells is lower than lithium ion, so a different BMS is needed, but you still need one.
Also, if your equipment needs more than one lead-acid battery in series for a higher voltage, it'd be best if your lithium replacement's BMS could see across the whole string of cells. Example: a typical smallish UPS will use two lead-acid AGM batteries and work at 24 volts. So best to build a single replacement lithium battery that is the physical size of two of the original batteries, with a single BMS that looks across the full 24 volts of lithium cells. See point #1 for why.
@@ScottyDMcom
Thank you so much that you have taken pains in highlighting me on charging and the need of the BMS in lithium based cells. From the explanation I could get that the lithium based cells require proper charging voltage and the charging is not dependant on the how much current goes in to battery pack. Am I right in this understanding? Please correct me if not?
Bos can i used this as a alternative for my solar power system
ANd also far more likely to burst into flame.
What is the tool that you use to attach the metal strip to the batteries?
Please instruct users to put a clear sticker on the battery about converted to liion and the max charge voltage.
Can the battery be used in a UPS (Uninterruptible Power Supply) Battery Backup?
Hi, What modification do I need to make to use it as car jump starter?
Thanks
can you this as replacement battery for ups?
Nicely done man.👍
can this be used as replacement for a 12V 7AH battery inside a UPS I have APC BX625CI-MS
I was wondering the same thing. I tried different lead acid brands and they seem to last 3 years tops. Seem even a NINH thing that can work for a few seconds would even be a great idea.
Presumably you did this for fun, because there is absolutely no way that it is cost effective.
Where the volume and weight are not an issue (like my garden shed full of solar-charged-backup batteries) sealed lead acid are far safer, miles cheaper and require almost no management electronics (just a standard charge controller). AND my shed hasn't burst into flames yet.
In the long term when the cells get mismatched, will it overcharge the good cells since the bad cells may be lower than 4.2?
the BMS has a balance ic, the chip use resistors to drop the battery voltage when pass 4,2v, and stop discharging the cell at ~4,19v, so it's necessary to charge the pack a little bit more than 12,60v, like 12,65, 12,70...
I use an led as indicator for each cell, the led (with current limiting resistor) is in parallel with the big resistor, so I know when the BMS is balancing and which cell get charged first...
The parallel connected cells are forced to remain at the same voltage as each other by the simple fact that they're all connected. The circuit handles balancing each set of parallel cells with the other sets.
amazing job. Thanks buddy, you're genius
7:06 "twice less" ← i can finally interpret this correctly, because of the scale. It's supposed to mean "half" - in this context "it weighs less than half". I've noticed this phrase on the Kreosan (English) channel, a few years ago, but wasn't quite sure what it actually meant.
Complimenti.
thank you
The lead acid batteries can be still fixed dont they?
can i use this 12v 14Ah Lithium-Ion Battery Pack to power the 99gear spot welding board the one with a purple pcb?
i hava a atv electric 36v 36ah 1000w lead acid batteri. can i convert this to litium batteri with same volt ?
I got a new battery for my electric bike it’s a 36 volt 14 amp battery but when I ride around or going over bumps it cuts off like it’s shorting out I think something in the battery pack is loose or something how would I fix that
what are the charging specification? tq
sir 4ams 12v incoming voltage two batteries 9.9ah and we can upgrade anything
I noticed that you charged the completed battery on a (Li-Po) setting rather than (Li-ion) Is this safe to do so? your charger is capable of (Li-ion) charging.
its safe , on lipo setting charge max voltage is set to 4.2v on li-ion is 4.1v
@@MrDexi87 wouldn't it be irrelevant which Lithium setting it's charged with, as long as the whole pack isn't over-volted? I mean could this pack be used (and charged) like an SLA Pb battery? That's why there's a BMS, right?
@@fluffyfloof9267 true , but if u charge 1s with 4.1v max voltage u can increase battery life, that's why imax b6 using lower voltage for charging li-ion cells ...
@@fluffyfloof9267 I'd like to know this as well. BMS's generally seem pretty straightforward in their operation, except when it comes to charging the cells properly once everything is assembled. This video was basically the first example I've seen where the creator actually touched on this area but still I have some unanswered questions... Like do these cheap BMS's disconnect charge when input voltage exceeds the lipo voltage ratings? What is the safe charge voltage and amp range for a 3S7P pack with a bms like the one in this video attached to it? I realise that depends on the cell specifications but in general (assuming mixed cells) what would be an average safe range for such a battery? And just as importantly, what WOULD HAPPEN if you used one of these batteries as an SLA replacement in a typical standby 300-600W UPS, for instance? Would it be safe? If not, why not? If someone says it's a 3S Li-Ion battery and therefore lower nominal voltage than the SLA it's replacing, that doesn't really explain why it's not suitable. We know that most UPS's will cut out at around 10.5v and charge up to max of around 15v. if the BMS can cut off charge at appropriate times (10.5v - 12.6v = 3.5v - 4.2v per cell, respectively) then there should still be an overlap range of compatibility even if its not a perfect match, yeah ? As far as I can see, all it means is that the cells will never fully discharge further than 3.5v, which is a good thing because it means way more use cycles. Sure you won't get the full 14ah of capacity, but even if you get the 7-9ah of the original SLA battery, it seems like a win
where are you going to use this for?
Can this be used in 12v 7ah ups safely...
not rentable
I'm a child of a very poor house, don't break my dream like this, don't kick me in the stomach, please
Creative video, thanks :)
What was the advantages and disadvantages of such batteries in this conversion?
Bro you need to dyor, the world isnt here to answer questions and if they answered that question, you would have a million more. Go learn stuff and be an adult
How do you dispose of the contents of the old battery? This is definitely very toxic material, right?
What’s the advantage?
Could I insert these directly into a desktop UPS (230V AC, 2kVA, 1.2kW, 2x12V9Ah lead acid batteries)? My intuition tells me it should be fine, as long as the LiPo cells can draw sufficient current (for 2Ah cells, that would be a C-rating of at least 2000/24/7/2=6), and since the charge voltage of lead-acid batteries is typically 12.7V or less, but I prefer to be safe than sorry and double check this. Understandably, the UPS datasheet doesn't provide information on internal charging circuitry, so I'm not sure how to proceed safely.
No this guy made it wrong actually 4S battery pack is real alternate to 12v lead acid batteries
Excelente proyecto muy bien desarrollado y mejor ejecutado , gracias por compartir sus conocimientos y experiencias , un saludo cordial y por supuesto un gran like desde Narón , Galicia ( España) 🤓 😜
Pls link the holder!
how I can get that PCB modul ???
How many amps to charge this device ?
No balance leads?,,no high temperature cut out?,,no low temperature cut out??
Aka, an accident waiting to happen! 😉
could someone help me. so i have made one of these battery but not to sure on how to charge it and i dont have a balance charger. any ideas would be gratefull.
Beautiful. Cheers.
Would you be able to use this method as a drop in replacement for a UPS?
Well, you can buy them for UPS, so I would think so. UPS chargers are gentle, and the voltage is right.
@@Bob_Adkins That's what I was thinking. The BMS is built into the battery in this design so it should be alright.
The main thing is the estimated time on battery and battery percentage probably won't be accurate and I'm not sure you could calibrate it given the differences in voltage drop between Li-ion and lead acid.
That could complicate things for controlled shutdowns when the UPS gets to a certain battery level/time remaining.
@@your_new_sjw_waifu Yeah, if your UPS reports battery condition, it will be inaccurate but you can mentally compensate. I think it's worth it, lead-acid batteries are awful, last only 2 years for me. The LA batteries can also show a false voltage, they check 12-13v but when power trips they only last a minute. Load testing twice a year is a headache. Li-Ion is usually good if the voltage is good, and should last many years if kept at 4.0v per cell. Li-Ion doesn't like to be stored at maximum voltage (4.2).
@@Bob_Adkins Yeah, I could mentally compensate but I couldn't have my computer reliably shut down and turn the PSU off when battery level reached 5% or there's 5 minutes remaining (whichever comes first).
Risk of unclean poweroffs really defeats most of what makes a PSU worth it to begin with.
@@your_new_sjw_waifu Your concerns are real, it's not a perfect solution. Someone should make a BMS that will make the battery voltage correct, and act just like a LA battery.
Ignoring the voltage discrepancy using 3 in series instead of four, those 21 18650s would cost over $80, while the lead acid would cost $25 to $30. Even using 15 to more closely match the 9Ah would cost $45 to$50.
Plus if you had it in an application where it’s charged by a source who’s voltage varies, like an alternator, you would need regulator circuitry to make sure the lithium batteries don’t get over-voltage and wind up burning down whatever you put them in.
The real question is why would you even do something like this? The one benefit lithium has over lead acid is energy density. So unless it’s for a portable application, you’re spending 2.5 - 3 times as much for no benefit.
New cells would be expensive 💰. At 2:20 he mentions that he recycled good cells from power tool battery packs. 👍
One serious issue with these lead acid batteries is that they often fail prematurely over winter. Lithium ion cells can survive cold winters. This size battery is used in golf carts and lawnmowers which are stored over winter.
Kay app bana kar bhej sakte hai 12 v ka battery
Thanks, but why did you set the charger to Lipo instead of Lithium?
Can this work for a motorcycle battery?
Can i use it for Scooters ?
But, the alternator Voltage coming out is more than 12.6V is the issue.!
You need 4 lifepo4 cells, they are perfect for 12v
Healthy.
What I don't see here is a list of the components and cost breakdown. Is it really worth all this trouble for a battery you can buy for $22 on Amazon?
Right. the lead acid battery is about $20-30, but lithium batteries in the same size as the lead acid battery are almost triple that, but worth paying for due to the higher number of recharge cycles per dollar, and because the spot welder alone costs over $50. I doubt I'll use the spot welder for anything else and finding defective" power drill batteries with an average cost of $0.80 per cell isn't something I do well. I've begun to establish limits to the things I want to DIY.
And you gotta love the disclaimer at the bottom of this video's description!
The question is where's the heat will go when those cells start building it up
Link to STL?
This is cool but I made a 3s10p 12.6v li-ion battery and I've got no idea what to do with it. I was originally going to use it as a camping battery in my car but I don't think you can charge it with an alternator as the voltage is too high ~14.4v. So I have a 12.6v charger but it plugs into AC power so if I wanted to use it in the car, I could hook up my inverter to the car battery and this charger to the battery, no problem. But now I have the additional problem of powering things with the 3s battery, because its voltage is too low to consistently power an inverter. The nominal charge of the battery is not 12.6v but 11.1v (3.7x3) and won't work for an inverter.
Honestly can anyone tell me what a 3s battery is good for?
Coooool..... very nice...👍🏻👍🏻👍🏻
Very good 👍
VERY COOL!!!!
how can 3.3 x 3 be equal to 12v>>>???
Why not 3D print a new case with the outer dimensions of an SLA battery and save yourself the exposure to the lead?
BMS is always a bottleneck for discharge current specs needed. Maybe smart switch to disconnect BMS while discharging battery would be good.
Hope you disposed of the lead properly so that it can get recycled. Overall you'd have been better off just putting the lithium battery into a new box in my view.
That was amazing.
not sure if your aware but this video was stolen and posted to facebook by one of those fake diy channels. they also replaced the original audio with a voiceover to avoid content matches.
Wait -- at 3:58 he solders on a bunch of short jumpers. Why was this???
The long ones connect each row of seven batteries in parallel. The short jumpers connect the rows in series. Without the short jumpers, each row doesn't produce 12 volts. That's the limit of my electrical knowledge.
The idea of using multiple jumpers is to share the load across several connections. In theory you could just use a single link to connect each parallel set in series, but using multiple links allows them all to share the load and run cooler.
Wish you have nice deal with those heavy metal, instead of throwing those in trash.