sunshine_eggo
Happy Breffast!
Just guessing. Sessions with max current balancing on each cell might alter the wiring resistances. I doubt it, but curious.
JKBMS balance lead voltage fluctuating
- Thread starter alexcl
- Start date
Just guessing. Sessions with max current balancing on each cell might alter the wiring resistances. I doubt it, but curious.
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
Ahem, the Elephant in the Room ! 3 Cells in Parallel !
The busbar (4/0) is a likely contributor but more likely that 1 cell is misbehaving and that would appear just as you describe. Test the 3 cells and see what their "independent voltage & IR are... It may also be prudent to yank the three out, top charge & balance them in parallel and re-test them.
Interesting, I just switched cell blocks 7 and 8 to see if the fluctuations persist on block 7 or switches to block 8. Unfortunately it's too cold to charge them where I live - will try again tomorrow.
I switched cell blocks 7 and 8 and find the same problem. I'm assuming that this would go away if it was caused by a cell with bad IR.
I measured the IRs of the potentially problematic cells and they look fine (and similar to the other cells).
I also converted the pack to 2p8s using cells from blocks 6-8 above as well as some others. All cells were connected only by busbars. I didn't see the same behavior. For some reason the increased resistance of the 4/0 awg cable seems to be causing huge voltage fluctuations as measured by the balance leads.
I also converted the pack to 2p8s using cells from blocks 6-8 above as well as some others. All cells were connected only by busbars. I didn't see the same behavior. For some reason the increased resistance of the 4/0 awg cable seems to be causing huge voltage fluctuations as measured by the balance leads.
Similar threads
