u/GoatVsOctopus

I recently build a new battery (with the old balance wires) because I thought the original one was EOL.
With the new one I still get the problem that according to the BMS the battery can go from 100% to 10% in seconds.
I measured the voltages at balance leads manually and everything seems fine.
Does this sound like a broken BMS? It reads like balance leads that's why I'm not sure if the balance leads may be flaky and were coincidentally good when I measured them but actually broken/unreliable connectivity.
Otherwise I would just get the PintV kit, or take the battery apart again and install new balance leads.