Sudden dishcarge


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Katarn_89

New member
Joined
Jun 10, 2018
Messages
9
So here I am dismantling laptop battery packs and when I grab the next set of cells to disassemble I notice that some of the cells are much warmer than ambient temps. I had only removed the cells from the plastic battery shell. I hadn't started to disconnect all of the cells from each other yet. I immediately took all 9cells from that battery outside. I disconnected the cells that were warm. There were 3 in parallel and it felt like the middle cell was the warmest so I wasn't sure if that was the only cell that was discharging or if the other 2 were also discharging. After a couple of minutes they cooled off and their voltages were almost but not quite at 0V. The other 6 cells didn't get warm and all have a voltage at about 1V.

I checked the 3 for any physical signs of damage or what might have caused them to suddenly start discharging and I didn't find anything so I don't think it was anything I did but they've been sitting around for a long time and only now discharged. Has anyone else seen behavior like this before?
 

Generic

Member
Joined
Oct 23, 2018
Messages
217
Most likely some tiny piece of metal fell into the tiny space at the top where the positive electrode is and temporarily shorted the positive and negative sides of the battery. Then the tiny piece of metal either melted or shook free and the short was gone. That's my guess. Its also my #1 fear when removing tiny pieces of nickel strips. I'm always careful that they dont fall into the gap.
 
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