I posted this in the lacroix is dead thread. But thought you guys might have some insight.
A buddy was about to send there lacroix vortex efoil into lacroix right when they went under. His efoil wouldn’t charge, I thought I help him out and check out the battery. Turns out one whole series row was dead.
My guess to what happened. Most likely he hadn’t used it in awhile (6-8 months), it was set to balance only on charging and charge only BMS. One row was low, would charge until overvolt on on a different row (set to 4.25V). Then use all the battery and the low row would be really low. Repeat several times until the row way undervolt and it doesn’t charge. Then put it away for a few more months.
Just replaced it that row now and got it all hooked up. Noticed 5/6 and 10/11 bouncing around only during balancing. BMS bad? Or is an artifact of how the balancing works on that bms? The actual voltage is solid on the battery. There are a balance fuses, if I short around them (by measuring the current with my multimeter) they jumping around appears to be much less. They all measured 3-4 ohm, but they all appear to at least not be open.
Have had it hooked up for several days now since the balancing might take forever with the large pack (14s8p p42a 21700). I could bring down those high cell manually with a dc load if needed.
Had to extend the nickel out on the row I replaced so not as pretty as I’d like:
