The invention discloses a method, a system, an electronic device, and a storage medium for determining performance of a power battery. The method includes the following steps: acquiring historical data of the power battery in at least two charging processes; determining, according to historical data in one charging process, a dQ/dV curve and a direct current internal resistance corresponding to said charging process; calculating a relative change rate of internal resistance capacity in any two charging processes; and determining the performance of the power battery according to the relative change rate of internal resistance capacity and a relative change rate of internal resistance capacity range corresponding to fault type. The invention can effectively determine whether the performance of the power battery is abnormal by combining, in the two charging processes, the target peak value of a dQ/dV curve of the power battery and the change in direct current internal resistance.