Repair shorted battery

[Lopezlarry]

Looking for advice on repairing a shorted battery

[DickB]

What do you mean by "shorted"?  Need more details - age of battery, symptoms. Does it charge? Work at all?

[Eric7]

●●● Battery repair or even opening up a battery is dangerous. You can hurt yourself and burn down the house. ●●●

I am guessing there is a chance for repair but you have to know what you are doing.
I think there are fuses, so the battery does not blow up and have a thermo meltdown in a regular short - but who knows.  So was there a big explosion, heat, smoke?  Then it is hopeless.  If there was just a small arc then maybe there is hope.

Plan one: Check and replace the fuses on the outside.

Plan two: Plan 1. Open the battery, replace the burned out hardware like some wires and connectors. But this is risky if you are wrong or don't know what is going on, or leave some bad parts unreplaced.

Plan three: High risk.  I don't recommend it.  Open it, check each bank of 4 cells for health.  Voltage.  Ability to hold a charge. You need a power supply, and volt meter. Throw out all the bad cells. Consolidate all the good used cells into banks of 4. Don't parallel a good cell with a bad cell.  If you don't have enough cells, you need buy and make new banks of 4 parallel cells. You may need to spot weld cells.
Get another battery management system - I think some people here know where to get something similar to what Rad uses. Solder it on.
Then you need to test the system.  Run it down, charge it up.  See if everything is working correctly and all the cell banks are charging up and balanced by the BMS after a charge.
Replace all burned up hardware.  Put it all back together securing everything so things don't bounce and disconnect.  Reseal the casing so water would not intrude.  Then test it again.  This is once again dangerous because you can start a fire charging a defective battery.

That's basically it.  It is not that complex but would require tools, practice and experience etc. In the end, you won't save money and you will have a rebuilt battery of dubious reliability (unless you are experienced but then if you are you won't be asking).  Also, depending on your skill and attention to detail and damage, the repaired battery may look like a hack job on the outside. If there is a short you can start a serious fire.  I wouldn't charge such a battery when I am sleeping.
 
Considering the time and labor and risks involved, also considering the time away from your family and friends, you should just buy a new battery.  Enjoy life.

[jbfoster]

I think of myself as pretty smart to work on a battery but I wouldn't mess with trying to repair a battery. Just to dangerous of burning down the house.

Jim