Active Balancing Method for Battery Cell Equalization

The emerging need for more power has led to the development of series-parallel connected battery cells. Having a more complex system also brought with it new challenges. One of these is the problem of cell imbalance. Balancing algorithms are based on extracting or adding charge in order to have balanced cells. Their goal is to protect the battery from damage and to help prolong the battery’s life. Without a balancing system the individual cell voltage will drift away, the total capacity of the pack will decrease more rapidly during operation and also the estimation of the state of charge will be unreal. This paper presents the theory behind the most important balancing algorithms developed so far and also proposes another method of cell balancing, method tested both through simulation and implementation.