With the development of the electric vehicles, serial connected cells have a broad prospect in the future. But the difference of the serial connected cells especially for Li-ion cells is prone to cause a lot of problems, such as overcharge and overdischarge. For these reasons, various cells balancing methods are applied. In this article main balancing methods will be compared, and as a result, the inductive charge transfer method will be adopted to balance the cells due to its obvious advantages. Furthermore, the principle and the realization of this balancing system will also be explained.