I used this BMS for the past year or so. Its worked fine. I was using crappy low powered 18650’s in my last pack, but it worked, just slow… I decided to upgrade my battery pack and soldered together this battery pack with samsung 25R’s.
My problem: Its been sitting for a week waiting for me to print a new case. In the picture you can see two cells died, or 4 since its 10s2p. This is the second time i let the pack sit for a week waiting for parts and i come back and part of the pack is dead. Last time I pulled the cells out and all 4 were 0voltage. So I am assuming this is also what has happened. Both times I put together the skaeboard with some tape and rode around just fine.
The blue line shows the voltage over the past few days on one of the cells, the other cell is similar. Can anyone make sense of why it would just go crazy like this?