Design of sinusoidal current charger with optimal frequency tracker for Li-ion battery

In this paper, a sinusoidal current charger (Sin-CC) with optimal frequency tracker is proposed for Li-ion battery. The proposed optimal frequency tracker is mainly constructed by the phase-lock-loop so that the features of detecting, tracking and locking in the optimal charging frequency can be achieved. The experimental results show that the charging speed charging efficiency and increasing surface temperature of the proposed Sin-CC are improved about 5%, 5.5% and 51.5%compared with that of the conventional constant current charge system.