Love the demeanor my man, thank you for putting in the time to share that information with all of us. I found it useful and will be diving in this afternoon. Thx again, cheers
Honestly this video helped me so much. When the video got to the end while I was watching it on the tv I couldn't find it again no matter what I searched for, only by using the computer upstairs and looking at the "history" was I able to find it again. You deserve a lot more views. I got 2 really helpful tips from this video. 1:Isolating the cells from each other by just removing the nickel from only the positive side (I never thought of this, I was going to strip from the back also) 2: those actual numbers and what to shoot for when charging. I have a power supply turning up tomorrow, it looks similar to what you are using, I am hoping I can bring all my series sets up to within .02V of each other. What settings would you suggest to use if I was going to charge just 1 cell up to around 4.1V so it matched all of the others? How many amps would be safe to use? I didn't realise you could charge the individual series up while all the nickel was still attached. And I still can't get my head around how the charger can pinpoint just that one parallel group even though every cell in the battery are welded together with nickel. But i'm just glad I do not need to strip it all down (unless a cell is knackered) Can i disconnect a BMS board by just removing the negative wire that is attached to the 1st set of parallel cells to the B- terminal on the BMS board? would that be good enough to "bypass the BMS board to allow me to charge up the battery as normal using the normal charger for a bit to bring up the average voltage of all of the cells? Sorry for all the questions. I have an E-bike battery here that is damp inside and some rust has formed on a few LG cells which are testing below 1V, so I was not even going to attempt to revive those and I have since ripped them out but the rest of the cells are still fairly high on the same series circuit (3.6v) and I think those are probably going to be ok. The guy must have been riding through a deep flood for that kind of water ingress... but nevertheless. I would like to try my best to bring it back up to perfect health. And if I can't, there are many good cells in the battery for good use anyway. All the other 75 or so cells are measuring at 4.11V, so I feel pretty confident it is only the 1 or 2 cells that are corroded and knackered from water damage. Hoping the BMS is not knackered. Cheers for the awesome vid
You should look at the datasheet for your particular cells to know the maximum charging current, but usually a 1C rate works well, so for a 3aH battery you could charge it up to 3 amps for a fast charge, or 1 amp for a slower charge.
No problem! Lithium batteries are fun to work with, but make sure you are prepared to put out a fire! I took some batteries to a local recycling company the other day and when they put them in their storage tote some of them caught fire from short circuiting!
@@dragon_offroad I am so paranoid about that. Hopefully my paranoia will ensure I do everything 110% safely. I'm not skimping on materials, cells, tools and I'm not rushing anything. But just in-case I may keep a little bag of sand outside to smother a battery with if anything starts smoking. It's right at the top of my list of worries for sure.
I wanted to thank you for making this video! I've been troubleshooting a battery pack on an electric scooter and couldn't find anything specific like your video. It's a 13S4P 48V pack and the BMS wouldn't let it charge. One of the cells was testing 0.856 volts and I was wondering if you could in fact charge an individual cell with a power supply. Awesome info!
@@dragon_offroad Ok. Would I be safe to slowly charge that series then let it sit for a few days then check again? It sat in the garage all winter then wouldn't charge when we tried this Spring.
Thanks for the video. I have a similar situation in my eskate board battery pack. The pack only charges to 89% and cuts out rather early. I suspect that there is one bad cell in it. Since I didn't build the pack I don't have access to more cells of the exact same kind. Since you said you would probably replace the faulty one after you found it do you have any advice on what cells to look for in such a case? Same brand, same type? but the batch obviously can not be the same. Similar age, usage, capacity, internal resistance but different brand?
This pack ultimately had nothing but problems due to the cheap cells. Many more of them started dropping off to zero and self discharging after I fixed it. But if you want to fix it, yes, you need replacement cells that are as close to the originals as possible
I have my 72v battery all taken apart thanks to you. One set of cells on mine are reading 3.0 volts all others measuring 3.9. Do those need replaced? I already have them pulled out so will be easy to fix
It may just be one of them in that series pulling all the others down! I would charge them up and test them all individually and find the one bad one that is dropping voltage way faster than the others
I have a 52v 20ah battery. Charges to full capacity, reads correct voltage on multimeter, will work perfectly with no rider on the bike but soon as its under load with weight on it. Totally shuts down & wont power back up till i disconnect & reconnect it. Then will do the same again. Thinking of doing a BMS bypass on the discharge side. Do you think it sounds bms related
@@dragon_offroadThanks for the reply dude. I've just done the BMS bypass on the Negative discharge cable, so we will see if it's sorted it out. Fingers crossed & will keep you posted 🫶🏻
@@dragon_offroad I have a 36v 10.4 Ah 10 series pack out of an E scooter, the batteries had very little use but were left to go completely flat for too long. I have unwrapped the pack and tested each of the series. Most measure 0.3v except a couple are around 3.4v. None are 0v. I was wondering if I charged the series individually with a lab power supply similar to yours if they might be recovered but I'm not sure.
I have a 70ah limitless lithium battery, and I can I put a 25ah limitless lithium charger on it, and in just a few moments the light turns green showing it's fully charge, and I'll check it with multimeter, and voltage is 14.8. Then I'll remove or take charger off, and check it immediately. The voltage immediately shows 2.75 volts, and drops to 0 volts in a matter of moments! Do you have any idea what would be causing this? Can 1 bad cell cause this? The reason I ask is because it shouldn't charge at all if the charger is connected.
@@lareneowenby3106 I would say yes! Bms is low voltage cutoff the output input charge switch because one cell is below the threshold. I would measure all series voltage and charge the lowest one to match the others, and if it keeps dropping find the bad parasitic cell and replace
It's hard to say it's the bms until you have measured all cell voltages both static and under load and guarantee none of them are more than ideally two hundredths of a volt apart
What voltage is the xiaomi rated for? If you overvolt something it will produce a lot more heat and burn out if you aren't also engineering a better way to keep it cool
@@dragon_offroad thanks, I'm not a enginner, but I understand a little, i know how to connect the motors with speed controller 350w 36/48v, and others like light, brake ...(and repair thinks),
Doesn’t 48 V supposed to come out to 54.6 V that’s what it supposed to come out yeah They gave me a charger and the DC is two a so the output is 54.6 V input well that don’t matter or maybe it does. I’m not a electric bike expert will input it says AC 100 to 240 V and 50/60 HZ and that’s just for the 48 V battery I would really like to hook up to my bike if the battery shuts off and if it shuts off if that means the BMS is shutting it off, there’s a reason and because of my extensive studies and homework on watching how to fix all electric bikes on TH-cam everywhere for everything I was able to figure that out pretty quick Because my power turns on when I plugged the charger in for five seconds and then pull the charger out and it’s riding again and then it would cut off again but when it cuts off, let me get this clear. I have to be near outlet somewhere because if not, it’ll either show no bars and the power won’t come on unless I do that charger trick or one bar would be there, but the drop would drastically go down from full to one bar and still it shuts down, but it allows me to shut the power off and on I could still see that one bar That’s when I stopped using that battery and I use my own battery. I put my old battery back in but now I got this new battery. I wanna know what China sold me because they made it sound like I was gonna get a great deal and if there’s something wrong with it well there is something wrong with it Because it’s not supposed to just shut off like that. It’s telling me something. It’s trying to tell somebody something somebody who knows how to speak to the electric bike and that’s not me. I don’t know how to do that. I wish I did. I need advice. I appreciate it thank you. I gave you any information that I had. If you need to know anything else I will reply because this is a important subject for me great content, and have a great one.
Love the demeanor my man, thank you for putting in the time to share that information with all of us.
I found it useful and will be diving in this afternoon.
Thx again, cheers
Honestly this video helped me so much. When the video got to the end while I was watching it on the tv I couldn't find it again no matter what I searched for, only by using the computer upstairs and looking at the "history" was I able to find it again. You deserve a lot more views.
I got 2 really helpful tips from this video.
1:Isolating the cells from each other by just removing the nickel from only the positive side (I never thought of this, I was going to strip from the back also)
2: those actual numbers and what to shoot for when charging.
I have a power supply turning up tomorrow, it looks similar to what you are using, I am hoping I can bring all my series sets up to within .02V of each other. What settings would you suggest to use if I was going to charge just 1 cell up to around 4.1V so it matched all of the others? How many amps would be safe to use?
I didn't realise you could charge the individual series up while all the nickel was still attached. And I still can't get my head around how the charger can pinpoint just that one parallel group even though every cell in the battery are welded together with nickel. But i'm just glad I do not need to strip it all down (unless a cell is knackered)
Can i disconnect a BMS board by just removing the negative wire that is attached to the 1st set of parallel cells to the B- terminal on the BMS board? would that be good enough to "bypass the BMS board to allow me to charge up the battery as normal using the normal charger for a bit to bring up the average voltage of all of the cells?
Sorry for all the questions. I have an E-bike battery here that is damp inside and some rust has formed on a few LG cells which are testing below 1V, so I was not even going to attempt to revive those and I have since ripped them out but the rest of the cells are still fairly high on the same series circuit (3.6v) and I think those are probably going to be ok. The guy must have been riding through a deep flood for that kind of water ingress... but nevertheless. I would like to try my best to bring it back up to perfect health. And if I can't, there are many good cells in the battery for good use anyway.
All the other 75 or so cells are measuring at 4.11V, so I feel pretty confident it is only the 1 or 2 cells that are corroded and knackered from water damage. Hoping the BMS is not knackered.
Cheers for the awesome vid
You should look at the datasheet for your particular cells to know the maximum charging current, but usually a 1C rate works well, so for a 3aH battery you could charge it up to 3 amps for a fast charge, or 1 amp for a slower charge.
@@dragon_offroad Ah yes! I didn't know datasheets were a thing! I will get on with that tomorrow.
Thank you very much for helping me out with this
No problem! Lithium batteries are fun to work with, but make sure you are prepared to put out a fire! I took some batteries to a local recycling company the other day and when they put them in their storage tote some of them caught fire from short circuiting!
@@dragon_offroad I am so paranoid about that. Hopefully my paranoia will ensure I do everything 110% safely. I'm not skimping on materials, cells, tools and I'm not rushing anything.
But just in-case I may keep a little bag of sand outside to smother a battery with if anything starts smoking.
It's right at the top of my list of worries for sure.
I wanted to thank you for making this video! I've been troubleshooting a battery pack on an electric scooter and couldn't find anything specific like your video. It's a 13S4P 48V pack and the BMS wouldn't let it charge. One of the cells was testing 0.856 volts and I was wondering if you could in fact charge an individual cell with a power supply. Awesome info!
You can but if that's the only series that dropped that low it may have a bad cell in it self discharging too fast
@@dragon_offroad Ok. Would I be safe to slowly charge that series then let it sit for a few days then check again? It sat in the garage all winter then wouldn't charge when we tried this Spring.
@@dragon_offroad one other series measured 3.650
Definitely can't hurt to charge it level with the pack and see how quickly it takes to drop again
@@dragon_offroad sweet! I'll report back. Lol!
Thanks for the video. I have a similar situation in my eskate board battery pack. The pack only charges to 89% and cuts out rather early. I suspect that there is one bad cell in it. Since I didn't build the pack I don't have access to more cells of the exact same kind. Since you said you would probably replace the faulty one after you found it do you have any advice on what cells to look for in such a case? Same brand, same type? but the batch obviously can not be the same. Similar age, usage, capacity, internal resistance but different brand?
This pack ultimately had nothing but problems due to the cheap cells. Many more of them started dropping off to zero and self discharging after I fixed it. But if you want to fix it, yes, you need replacement cells that are as close to the originals as possible
I have my 72v battery all taken apart thanks to you. One set of cells on mine are reading 3.0 volts all others measuring 3.9. Do those need replaced? I already have them pulled out so will be easy to fix
It may just be one of them in that series pulling all the others down! I would charge them up and test them all individually and find the one bad one that is dropping voltage way faster than the others
You are using an inductive load across a dc source to discharge the higher parallel group. Would that not be a short ?
It is simply a resistive load, not inductive.
I have a 52v 20ah battery. Charges to full capacity, reads correct voltage on multimeter, will work perfectly with no rider on the bike but soon as its under load with weight on it. Totally shuts down & wont power back up till i disconnect & reconnect it. Then will do the same again. Thinking of doing a BMS bypass on the discharge side. Do you think it sounds bms related
@@TheBigwesb it's possible, I would check all series voltages static and under load, but yeah most stock bms are garbage
@@dragon_offroadThanks for the reply dude. I've just done the BMS bypass on the Negative discharge cable, so we will see if it's sorted it out. Fingers crossed & will keep you posted 🫶🏻
So when you were testing the voltage on the individual series was the charger turned on or did you test it in it's static state?
@@donaldsayers4967 those were static tests. The series with the parasitic cell will be much lower voltage than the rest.
@@dragon_offroad I have a 36v 10.4 Ah 10 series pack out of an E scooter, the batteries had very little use but were left to go completely flat for too long. I have unwrapped the pack and tested each of the series. Most measure 0.3v except a couple are around 3.4v. None are 0v. I was wondering if I charged the series individually with a lab power supply similar to yours if they might be recovered but I'm not sure.
@donaldsayers4967 I'd say it's worth a shot to charge them and do a capacity test if you have the time and a use for the pack
I have a 70ah limitless lithium battery, and I can I put a 25ah limitless lithium charger on it, and in just a few moments the light turns green showing it's fully charge, and I'll check it with multimeter, and voltage is 14.8. Then I'll remove or take charger off, and check it immediately. The voltage immediately shows 2.75 volts, and drops to 0 volts in a matter of moments! Do you have any idea what would be causing this? Can 1 bad cell cause this? The reason I ask is because it shouldn't charge at all if the charger is connected.
@@lareneowenby3106 I would say yes! Bms is low voltage cutoff the output input charge switch because one cell is below the threshold. I would measure all series voltage and charge the lowest one to match the others, and if it keeps dropping find the bad parasitic cell and replace
Does that battery pack not have bluetooth bms? Couldn't you just use the bluetooth to monitor the voltage in the series?
@@jungbae3 this one does not, but many of my bigger electric motorcycle packs do, and that is what I would recommend.
How many pieces of cells is it made of?
13s8p, 104 cells
What happens if BMS goes bad? and what would cause this to happen? Thanks
It's hard to say it's the bms until you have measured all cell voltages both static and under load and guarantee none of them are more than ideally two hundredths of a volt apart
Is the voltage low on the series or parallel packs?
What if some of my cells are 4.5 volts ?
That is overcharged for a li ion cell. You should discharge them to 4.2v asap. They may have sustained damage
@@dragon_offroad how would I discharge them ?
The whole pack reads 58.3 when fully charged and some cells read 3.8 could that have been from bms fault ? And how exactly could I discharge them ?
Hi, plz I have a question : can I run a Xiaomi (250 watt) with 36v hoverboard battery?? ( I make path just a 2km in day) , plz someone answer me. tnx
What voltage is the xiaomi rated for? If you overvolt something it will produce a lot more heat and burn out if you aren't also engineering a better way to keep it cool
@@dragon_offroad thanks, I'm not a enginner, but I understand a little, i know how to connect the motors with speed controller 350w 36/48v, and others like light, brake ...(and repair thinks),
Doesn’t 48 V supposed to come out to 54.6 V that’s what it supposed to come out yeah They gave me a charger and the DC is two a so the output is 54.6 V input well that don’t matter or maybe it does. I’m not a electric bike expert will input it says AC 100 to 240 V and 50/60 HZ and that’s just for the 48 V battery I would really like to hook up to my bike if the battery shuts off and if it shuts off if that means the BMS is shutting it off, there’s a reason and because of my extensive studies and homework on watching how to fix all electric bikes on TH-cam everywhere for everything I was able to figure that out pretty quick Because my power turns on when I plugged the charger in for five seconds and then pull the charger out and it’s riding again and then it would cut off again but when it cuts off, let me get this clear. I have to be near outlet somewhere because if not, it’ll either show no bars and the power won’t come on unless I do that charger trick or one bar would be there, but the drop would drastically go down from full to one bar and still it shuts down, but it allows me to shut the power off and on I could still see that one bar That’s when I stopped using that battery and I use my own battery. I put my old battery back in but now I got this new battery. I wanna know what China sold me because they made it sound like I was gonna get a great deal and if there’s something wrong with it well there is something wrong with it Because it’s not supposed to just shut off like that. It’s telling me something. It’s trying to tell somebody something somebody who knows how to speak to the electric bike and that’s not me. I don’t know how to do that. I wish I did. I need advice. I appreciate it thank you. I gave you any information that I had. If you need to know anything else I will reply because this is a important subject for me great content, and have a great one.