Passive balancing design for Li-ion battery packs based on single cell experimental tests for a CCCV charging mode

High power battery systems are composed of big array of series connected single cells. The main reason of increasing battery pack voltage is, to increase power by decreasing current and improve the efficiency. To control the charge and voltage of each cell a BMS with balancing system is necessary. Battery modeling is hard work, and battery dispersion and deviations are not taken into account. To overcome this problem, in this work a passive balancing system design procedure is presented based on single cell experimental tests. Battery modeling is avoided and main deviations between batteries are taken into account. Main parameters are taken into account during the design procedure. Finally design procedure is compared with experimental results.