BATTERY FAULT DETERMINATION

A system for monitoring the state of a battery comprising cell groups includes cell monitoring devices (CMDs) associated with corresponding cell groups and a battery management system (BMS). Each CMD measures properties of cells in the respective cell group using its sensor system and evaluates the measurements to detect faults at the monitored cells. When CMD detects a fault, CMD stores a fault indicator, indicating that the respective cell group experienced a fault, and fault data related to the detected fault, including a timestamp indicating when CMD detected the fault, for subsequent transmission to BMS. Upon waking, BMS receives and processes fault indicators and fault data shared by CMDs to determine action(s) responsive to the fault(s) detected by CMDs.