Method and apparatus for estimating battery state of health

An apparatus for estimating a battery state of health SOH, wherein the apparatus comprises an obtaining module and a calculation module, wherein

• the obtaining module is configured to obtain N states of charge SOCs of a target battery in N states, wherein the SOC is a ratio of a remaining capacity of the target battery to a full charge capacity of the target battery;
• and
• the calculation module is configured to:
• separately calculate first dV/dSOC data of each SOC in an nth SOC based on a charge/discharge capacity of the target battery in the nth SOC and an mth preset capacity of the battery, wherein N represents a quantity of SOCs, N is a positive integer not less than 2, n is a positive integer less than or equal to N, m is a positive integer from 1 to M, and M is a quantity of preset capacities;
• separately calculate, based on a dV/dSOC-SOC characteristic function, second dV/dSOC data corresponding to each SOC, wherein the dV/dSOC-SOC characteristic function is obtained by charging or discharging the target battery based on a preset current in an new battery state, the preset current is not greater than 1/20 QBOL, and QBOL indicates a retention capacity of the target battery in the new battery state;
• obtain an mth overall dV/dSOC data deviation of the plurality of SOCs through calculation based on the first dV/dSOC data of each SOC in the mth preset battery capacity and the second dV/dSOC data corresponding to each SOC;
• determine a smallest overall dV/dSOC data deviation from M overall dV/dSOC data deviations;
• determine a preset battery capacity corresponding to the smallest overall dV/dSOC data deviation as a retention capacity of an aged target battery;
• and
• obtain an SOH of the target battery through calculation based on the retention capacity of the aged target battery.