BMS (battery management system)

A BMS is the control and protection layer that keeps a battery pack within its operating limits. In a home battery system it may monitor cell or module voltage, current, temperature, state of charge and fault conditions, then communicate with the inverter or battery controller so charging and discharging stay within the manufacturer’s limits. Depending on the battery design, the BMS may also balance cells, restrict power or disconnect the battery if conditions move outside a safe range. BMS warnings or communication faults can explain why a battery will not charge, limits its output or shows a state of charge that does not match the usable energy expected.