BATTERY MANAGEMENT SYSTEM, BATTERY MANAGEMENT METHOD, BATTERY PACK, AND ELECTRIC VEHICLE

A battery management system includes a current sensor to measure a battery current through a battery, a voltage sensor to measure a battery voltage across the battery, and a control circuit. In response to a key-on signal during a first rest period of the battery, the control circuit determines a fixed rest time, a fixed Open Circuit Voltage (OCV) and a fixed State Of Charge (SOC), and determines an integrated current value of the battery current during a cycle period of the battery. In response to a key-off signal during the cycle period, the control circuit starts a second rest period of the battery. The control circuit determines an interest SOC corresponding to an interest OCV, i.e., the battery voltage during the second rest period. The control circuit determines a State Of Heath (SOH) of the battery based on the fixed SOC, the integrated current value and the interest SOC.