The Optimized Capacity for Lithium Battery Balance Charging/Discharging Strategy

This paper proposed an optimized strategy to enhance the capacity of a cascaded Lithium battery pack. An active balance system is used to elongate the life cycle of Lithium battery pack. The proposed techniques cover active balance circuit, digital balance control module and Lithium battery pack capacity optimized control strategy. By integrating E-class series resonant circuit, shunted multi-winding transformer, balance control switch and digital control module, the cell charging/discharging process will be divided into ten intervals. Every interval has its own linear voltage versus surplus charge capacity relationship with corresponding slope. Different proper balance factor is defined for each interval to determine the action of balance switch. The cell with voltage is below the average. The experiment is performed by using Lithium battery pack 16S1P to investigate the charging/discharging behavior of each cell and define balance factor to switching action of balance control switch. The battery pack function will be measured when experiencing charge imbalance and optimized strategy is employed to complete the balance requirement.