Originally Posted by dimitri
Does it stand out from the rest only under load? Does it read same as others without the load? Do the terminals/bolts on this cell get noticeably warmer than others? Sounds like extra voltage drop is developed under load at this cell, but it could be inside the cell ( weak/defective cell ) or outside the cell ( poor/dirty/lose connection).
If BMS alarm goes off on this cell even when you let go of the throttle, that means the cell does not recover above LVC even when load is removed, which certainly points to a weak/bad cell. Or maybe this cell is simply much lower capacity than expected.
One trick I use to find lose/dirty connections is to measure the voltage drop between the actual body of the terminal and the busbar attached to it, while charging at max CC current. You should see just a couple millivolts or less on a healthy connection. Establish a baseline by checking all of them , most should be in same small range. If you find some significantly higher, clean and redo that connection.
It does stand out when under load, and is also slightly lower than the rest when charged, but it does need a good individual charge to see if it can come up to the rest of the pack.
It scares me that I might have pressured the supplier to get me a battery. It had taken him two weeks before he even acknowledged that I bought one and that he'd send one as soon as he could. Then he said he had a friend that had one, and sent it to me. I'm worried that he sent me a used one. Plus, I've e-mailed asking about a replacement, and again, no response, though its only been 18 hours...