Design of Balanced Charging Circuit for Lithium Ion Battery

The lithium iron phosphate battery is chosen as the research object in this paper. The causes and solutions of the unbalanced battery is analyzed. In view of the problem that the accuracy of voltage as the criterion of balance needs to be improved, the State of Charge (SOC) of battery is chosen as the criterion of balance judgment. An inductive active equalization circuit is designed. Then the specific working process of the equalization circuit is analyzed, and the battery equalization mode is formulated. The simulation results show that the block equalization strategy improves the equalization efficiency by setting two thresholds: equalization threshold and cell equalization control threshold.