Method for identifying battery model parameters on line

The invention relates to the technical field of lithium-ion batteries and particularly relates to a method for identifying battery model parameters on line. The method specifically comprises the following process: step 1, establishing a battery equivalent circuit model, establishing a battery model equation, taking current and terminal voltage as known quantities and inputting the known quantities into the model equation; step 2, deforming the battery model equation and taking open-circuit voltage, resistance and capacitance as unknown parameters to obtain a difference equation; and step 3, calculating the unknown parameters, namely the open-circuit voltage, the resistance and the capacitance, through parameter identification. The open-circuit voltage is used as the unknown parameter and online identification is carried out by adopting a recursive least square with a forgetting factor; an experiment does not need to be carried out at an earlier stage, the cost is reduced and a parameter identification flow is simplified; and the difference between an open-circuit voltage experimental measurement value and an open-circuit voltage parameter value in an actual operation process of an automobile is reduced.