BATTERY MANAGEMENT UNIT AND METHODS OF USING THE SAME

A battery power management unit, BPMU (31), an electrical energy storage system (102) comprising one or more such BPMUs, and method of using the same are provided. The BPMU is configured to perform steps of: reading data from the internal battery management unit, BMU (25), of a respective battery pack (20) to establish capacity, an energy baseline, state of health (SOH), and an initial value of state of charge (SOC) of the respective battery pack, checking voltage and current at a time interval, calculating power of the respective battery pack, determining and updating battery date such as SOH and SOC, and transmitting updated battery data to a system controller (60) for controlling discharging power from or charging power to the respective battery pack. The battery pack (20) may be part of a grid-connected battery energy storage system (BESS) using second-use electric vehicle (EV) batteries.