Joint estimation of SOH based on capacity correction and partial correlation coefficient

State of health (SOH) of the power battery is often used as an important parameter to measure the aging of the power battery in new energy vehicles. This is of great importance for safe driving of vehicles. However, when estimating the SOH of the battery, it is difficult to measure the battery capacity accurately, which makes the estimation difficult. In this paper, to address the problem that battery capacity is difficult to be measured accurately in the estimation of dynamic SOH, the factors affecting the actual battery discharge capacity are studied through different test conditions, and the influence factors of different factors are derived, and then the weights corresponding to different influence factors are given by the method of partial correlation coefficient analysis. The estimated SOH value is obtained by adding the final weights to the actual maximum capacity value of the battery initially calibrated. Finally, the error is experimentally verified to be within ±1.8% on the collected data set of the actual maximum capacity released from the battery at different discharge multipliers. This satisfies the accuracy requirement and well solves the problem of difficult online identification of battery capacity in SOH estimation by the capacity measurement method.