dogman dan
1 PW
I agree, there is no obvious thing going on here to explain it. Discharge testing is going to have to be done to learn more.
I was hoping it was something dumb, like you didn't let it charge long enough to balance. It would be interesting to charge it, manualy if needed to full, then unplug the bms and see if there is any self discharging cells in there. I've seen that with my lipos. You get one cell that just loses 20% of it's voltage in a day or less. At that point, you just can't keep it balanced anymore and have to chuck it.
Then do the same test, watching the cells overnight with the bms plugged in. Maybe something is drawing a lot of current in the bms?
Only other thing I can think of, is you took too long soldering in the new cells. It has to be done quick. Other possibility, you just ran into bad luck with the new cells.
I was hoping it was something dumb, like you didn't let it charge long enough to balance. It would be interesting to charge it, manualy if needed to full, then unplug the bms and see if there is any self discharging cells in there. I've seen that with my lipos. You get one cell that just loses 20% of it's voltage in a day or less. At that point, you just can't keep it balanced anymore and have to chuck it.
Then do the same test, watching the cells overnight with the bms plugged in. Maybe something is drawing a lot of current in the bms?
Only other thing I can think of, is you took too long soldering in the new cells. It has to be done quick. Other possibility, you just ran into bad luck with the new cells.
