Estimating a battery state of health (SOH) is described. The state of heath is estimated by obtaining a partial charge or discharge capacity of a target battery in a state of charge (SOC) interval of each of a plurality of SOCs. First dV/dSOC data is separately calculated for each SOC in an mth preset battery capacity based on the mth preset battery capacity and the partial charge or discharge capacity in the SOC interval of each SOC. A smallest overall dV/dSOC data deviation is determined from all overall dV/dSOC data deviations corresponding to M preset battery capacities. A preset battery capacity is determined corresponding to the smallest overall dV/dSOC data deviation as a retention capacity of an aged target battery. The retention capacity of the aged target battery is divided by a retention capacity of the target battery in a new battery state, to obtain the SOH estimate of the target battery.