Study on Battery Model and Remaining Capacity Estimation of EV Driving Battery

In order to improve the estimation accuracy of the range of the electric vehicle (EV), it is necessary to grasp the remaining capacity of the driving battery. It is, however, impossible to measure remaining battery capacity directly. In this paper, we propose a remaining capacity estimation method of the EV driving battery. First, we built the battery model based on an equivalent circuit. Afterwards, we discharged the battery to estimate the parameters of the battery model. Then, we conducted a running test using the EV in order to measure electric power during driving. Finally, we confirmed the validity of the estimation method by estimating the remaining battery capacity utilizing the measurement results and the battery model.