Balance charging circuit for charge equalization

A nondissipative balance charging circuit based on buck-boost topology is proposed for charge equalization control for the series-connected batteries with serial charging scheme. The sub-circuit associated with each battery acts as a current diverter to divert the excessive charging current from the satiated batteries to the hungry ones. To equalize the state-of-charge among the batteries, the balance charging circuit regulates the average charging current in a dynamical manner. The applicability of this approach is confirmed by experiments.