Self-preheating Method for Li-ion Battery Using Battery Impedance Estimator

The performance of Li-ion battery’s cell is significantly reduced under subzero temperature. In this paper, a self-preheating method for Li-ion battery using battery impedance estimator is presented. For battery impedance estimation, no information of the actual battery’s internal impedance is required, so that the proposed method can be easily and quickly adapted to the commercial Li-ion batteries. In addition, the proposed method includes the optimization of charging/discharging current and preheating frequency using the battery impedance estimator. Moreover, based on DC- discharging estimation in the proposed method, the preheating procedure is automatically shut. Using the presented method the self-preheating method can be widely adapted to commercial applications. The feasibility of the proposed control strategy is verified by the simulation and experimental results.