A numerical model of Lithium-ion battery for a life estimation

A modelling method of Lithium-ion battery during its operation is proposed in this paper. The method is applicable not only to a numerical simulation of an equipment driven by the battery but also to a lifetime-estimation, because the internal impedance obtained by the method is able to represent its frequency characteristic, which expresses transient response and has a close relation to its life. No extra charging/discharging circuit and no removal of the battery from the equipment are required because the method using information during its operation. An accuracy of the proposed method is confirmed by a laboratory test and a running test of an electric bike.