EG4 › battery management system (BMS)
Battery SOC drops suddenly to 0%, triggers charging
reported more than once
Symptoms
Batteries stall around 80% SOC and stop charging, or drop suddenly to 0% (from 23%, from 44%, or straight past a configured 20% floor) and trigger unwanted AC charging, or never reach a true full charge because they are routinely charged only to 80-100% rather than a true 100%, or SOC-based charge control masks a small continuous EPS-standby draw until the BMS silently fails and the batteries drain to failure
The cause and the fix
Subscribers see the cause, the fixes that worked and who did them, part numbers and recent prices when a part is involved, and the field reports behind this entry.