An exact SOC-estimate mathematic model of open-circuit voltage and parameters estimation

This paper describes an exact SOC-estimate mathematic model, which uses the battery State-Of-Charge (SOC) as a state variable and can simulate the whole progress of discharge accurately. The model parameters can be calculated according to the experimental data. The correction parameter C influences the accuracy of the open voltage model and the paper puts forward the optimal parameter identification method to simulate it. Finally, the paper uses the optimal parameters to estimate the SOC and the SOC-estimate error is less than 3%, which is good comparing with the 8% the basic accuracy of the SOC-estimate for the city bus´s battery.