A battery management system (BMS) is any electronic system that manages a rechargeable battery (cell or battery pack), such as by protecting the battery from operating outside its safe operating area, monitoring its state, calculating secondary data, reporting that data, controlling its environment, authenticating it and / or balancing it.
A BMS may monitor the state of the battery as represented by various items, such as:
- Voltage: total voltage, voltages of individual cells, minimum and maximum cell voltage or voltage of periodic taps
- Temperature: average temperature, coolant intake temperature, coolant output temperature, or temperatures of individual cells
- State of charge (SOC) or depth of discharge (DOD), to indicate the charge level of the battery
- State of health (SOH), a variously-defined measurement of the remaining capacity of the battery as % of the original capacity
- State of power (SOP), the amount of power available for a defined time interval given the current power usage, temperature and other conditions
- Coolant flow: for air or fluid cooled batteries
- Current: current in or out of the battery
