Help with my overcharged lifepo4 battery. Whats Next?

avago

1 µW
Joined
Jul 4, 2016
Messages
4
First off, I'm from Cuba, so sorry my bad spelling.

I bought a 48v 20ah LifePo4 duct tape battery pack on eBay 14 month ago, I used every day around 20 miles(max 35 miles of range), the pack was performing like the first day until last week.
Two month ago I had problem with my lifepo4 48v 3ah battery charger and I replaced it for a 48v 3ah SLA battery charger(I know now that it was a mistake), and suddenly last week the battery pack got puffy(see pic 2), when I checked it out I found that the problem was the charger, it was outputting 109 volts DC(see pic 3). I don't know why but it was the cause of the super overcharged effect. I open a hole on every cell that was not open by the puffy effect to discharge the gas(pic 5).
It was a huge sacrifice for my to invert over 450usd on this battery pack, hoping it will last several years, because I live in Cuba and the standard SLA12v batteries here cost like 360usd(the pack of four) and only last one or two years at max.

I hope someone can recomend me if is a good idea to try to recover this battery pack, I measured the voltage of each cell and was the following:

3.36, 3.32, 3.34, 3.36, 3.38, 3.40, 3.40, 3.38, 3.39, 3.34, 3.40, 3.35, 3.43, 3.38, 3.38, 3.50
The whole battery pack is 54.1v (pic 4)

Supposing the battery don't finished the charging process when the problem occur, I think each cell has a good voltage, but my main concern is if the cells were damaged and if is safe to try to charge it again and use in my scooter.

Is a good idea to seal the holes and buy a new BMS and lifepo4 charger?

Thanks in advance to all you guys.
 

Attachments

  • 2.jpg
    2.jpg
    51.5 KB · Views: 1,202
  • 4.jpg
    4.jpg
    59.3 KB · Views: 1,202
  • 5.jpg
    5.jpg
    101.7 KB · Views: 1,202
Sorry to tell you but you probably killed the pack. It might have some usage now, but it might also be a fire danger. If you charge it again, be sure to put it in a place that won't be a problem if it catches fire. Keep an eye on it as you charge it in case something bad happens. Do this every time you charge it.

The holes in the cells also is a problem. Yes seal the batteries again. If any moisture got into the cells then it will degrade the cells further.

I am surprise the BMS didn't stop that 109v charge with over voltage protection. It is possible that the BMS is also now burned and not working right. The only way you will know if the BMS is working is to put the proper voltage charger to the battery pack and watch what happens.

For you pack to be properly charged it needs 58.4v from your charger. Each cell should be at 3.65v fully charged. (16 cells x 3.65v = 58.4v)The voltage
es you listed show that the cell voltages are low.

First you need a proper charger that works. Or you could try to charge the cells individually to 3.65v if you have a charger that can do that.

How many volts was going into the 109v charger 110v ac or 220v ac?

:D
 
Thanks for your reply.

e-beach said:
it might also be a fire danger. If you charge it again, be sure to put it in a place that won't be a problem if it catches fire. Keep an eye on it as you charge it in case something bad happens. Do this every time you charge it.
At the begining I was afraid to even move my motorcycle cos I had read liteon battery can get fire and explote but later I read that the lifepo4 batteries are very stable regarding this, I was hoping that the explode part were less probable with lifepo4.

e-beach said:
The holes in the cells also is a problem. Yes seal the batteries again. If any moisture got into the cells then it will degrade the cells further.
How can I seal this holes? I'll apreciate some natural advices or not to complicate glue because I live in cuba and here we have very limited things in shops.

e-beach said:
I am surprise the BMS didn't stop that 109v charge with over voltage protection. It is possible that the BMS is also now burned and not working right. The only way you will know if the BMS is working is to put the proper voltage charger to the battery pack and watch what happens.

For you pack to be properly charged it needs 58.4v from your charger. Each cell should be at 3.65v fully charged. (16 cells x 3.65v = 58.4v)The voltage
es you listed show that the cell voltages are low.

First you need a proper charger that works. Or you could try to charge the cells individually to 3.65v if you have a charger that can do that.
I'm sure the bms are broken, so I'll have to buy a BMS and the battery charger.

e-beach said:
How many volts was going into the 109v charger 110v ac or 220v ac?

:D
Only 110v AC, is the operational voltage of the charger and the standard here in Cuba.
 
My primary recommendation is to get a new battery. I am sorry about the expense, but your battery is in potentially dangerous condition now.

avago said:
At the begining I was afraid to even move my motorcycle cos I had read liteon battery can get fire and explote but later I read that the lifepo4 batteries are very stable regarding this, I was hoping that the explode part were less probable with lifepo4.

First seal the holes in the battery as fast as you can. LiFePO4 is less volatile then other lithium batteries, but it is still a lithium battery and can catch fire. I run LiFePO4 for the same reason you do. It is a very stable chemistry as lithium batteries go. But, you have punctured your cells which should never be done with lithium batteries. Do your best to find an adhesive that will stick to the aluminum outer part of the cells and stay adhered if the batteries get hot. Pinch the foil closed and apply the adhesive to keep the foil sealed and air tight. No air should get into the cells.

As for a new purchase, start with a new battery charger. You can always use it with a new battery when you purchase one. Also, sometimes battery chargers can be repaired. I repaired one once with help from ES. What was the problem with the original one? Also post a picture of it. Can your old charger be opened? Maybe we can help you with it.

Only 110v AC, is the operational voltage of the charger and the standard here in Cuba.

Then that charger is not of use for your battery unless it can be adjusted to 58.4v dc on the output.
 
Nail polish can seal the holes.

Should still be safe to use, other types of lithium could have caught fire overcharged like that. But still, charge it in a safe, fire resistant place now.

Expect less capacity from now on.
 
Wit the cells puffed up like that I wouldn't risk using them anymore. I'd safely discharge the pack as low as you can go and then recycle the pack. IMO its not worth the fire hazard or possible injury to yourself or property to continue running this pack when they have been exposed to about double their normal charge voltage.
 
I'm so sorry to hear about this loss for you--I can see it's a much bigger deal for you where you are than it would be for many of us.

As others have pointed out, you might be able to get more use out of this pack, but the risks are much higher now than before this event because the cell interiors have been compromised. In a puffy cell, the tight structure of the electrode stack gets distorted, and depending on the nature of the damage (for example, temps of 100C or so can melt separator) you may be risking an even more spectacular event in the future. It sounds like you had no choice but to puncture the cells to release the gas, but now atmospheric moisture has a path in, and your electrodes have already started to degrade as a result. A good seal will be very difficult to achieve and maintain, no matter what you do.

You've already vented the cells, so explosion risk is just about zero, no matter what you do. An internal short on a cell at a high state of charge could generate a lot of heat, possibly a fire. Or, electolyte could vent violently, possibly onto your body--that could be quite dangerous, especially if water splashed onto the same area at the same time. Water mixed with LFP electrolytes can form hydroflouric acid--VERY nasty stuff. A drop or two of electrolyte represents very little risk as long as it's not in your mouth or eyes. But electrolyte vapor spraying all over your leg would be a different story. A spark would set that vapor on fire, and if the electrolyte mist is allowed to accumulate in an enclosed area, there is a risk of explosion.

So that's a short list of possible bad outcomes, and should cover just about all of the worst things that might happen. Bueno suerte!
 
Well, thanks to every one for yours advices, I just buy another one, this time 48v 25ah lifepo4 and 3ah charger, for 470usd, eBay USA.

I know now that is very important to pay special attention to the charger because is a guarantee to have one with quality and in my case it was the cause of the problem. so I need some advice regarding where I can find a good quality battery charger for my configuration, I don't care if is 3ah or a more faster 5ah, so any advice will be much apreciated, my confguration is 48v 25ah 16 cells lifepo4 battery, AFAIK I need 58.4v charger right?

Thanks...
 
Getting a good battery charger is sometimes a problem. My $200 Kingpan charger died after 1 year and I had to fix it. My $50 vpower charger I bought on eBay has lasted 2 years even though I take it with me on trips. I put it in my back-pack as my on-the-road charger.

The best company to deal with around here is ebikes.ca. http://www.ebikes.ca/shop/ebike-parts/chargers/cycle-satiator.html
Their customer service is first rate, but...their chargers are expensive.

A 3a charger could take a long time to charge a 25ah battery. Like 10 hours or more if you battery is fully discharged. A 5a or 6a charge could be more convenient.

:D
 
Before you buy a battery please give us a link so we could help evaluate the battery before you buy. eBay usa whats that ? Please include the controller and motor you will be using.
 
eBay USA is what guys out of Dana Point get by default cuz your in the USA. Guys from other countries have to dial it up.

:D
 
999zip999 said:
Before you buy a battery please give us a link so we could help evaluate the battery before you buy. eBay usa whats that ? Please include the controller and motor you will be using.
eBay USA is because the products are in USA, but every one knows those batteries are from China.
All looks like this: http://www.ebay.com/itm/162077387429
Sellers are: electronicstore, zjlnb20092009, koyochen, imotorbattery
I think all are the same guy, I have a 1000w 48v electric scooter, from china. My former battery was identical to this, it gave me excellent results until I charged it with an SLA battery charger as I said before.
 
Hola amigo, te escribo en español porque eras cubano, mataste tus baterias al usar el cargador para baterias de plomo acido, las baterias de litio solo pueden cargarse con cargadores para ese fin, ya esas baterias no sirven. Lamentablemente tendras que comprar otro paquete. Te aconsejo lifepo4 que son las mas duraderas aunque un poco mas pesadas.
 
google translate said:
Hello friend, I write to you in Spanish because you were Cuban, you killed your batteries when using the charger for acid lead batteries, the lithium batteries can only be charged with chargers for that purpose, and those batteries do not work. Unfortunately you will have to buy another package. I recommend lifepo4 which are the most durable but a little heavier.

If you read the thread (which is a year and a half old), you'll see that he already knows what happened to the batteries and why (even in the first post), and he already bought a new LiFePO4 battery, though he was still looking for a quality charger for it the last time he posted.
 
Back
Top