Bad Cell

I just replaced a bad cell in my HV battery, it read 6.4 in the pack. The car has been fine for a week now thankfully. During the summer I'm going to do the pack again, this time balance, resistance test the cells, to make a stronger pack. For now I cut open the bad cell, and read the voltage on the inside cells. All the cells are 1.3v, but for one cell, that is .02v. Guess you can say this cell is dead. The battery is 9yrs. old, and the cells are all still wet and juicy when you squeeze the pack, so I guess it's not dried out. When I get a few more minutes, I'm going to drill out the rivets, and try to slide the cell out, and see if anything is obvious like deterioration, bad contact to the rivet, broken plate connection, or something like that. I'll post again when I get it out, I'm really curious now. View attachment 64656 View attachment 64656 View attachment 64656 View attachment 64656

 

Thanks, I used a jigsaw, about a 1/4 from the top, all the way across.lol

I charged the one bad cell bad to 121o mAh twice, and it died as fast as I pulled the charger off. When they're dead, their dead. I'm now running 3 cycles on a good cell in there, and seeing if I can pull more milli amps from it each cycle like your supposed to be able too