An active cell balancing circuit based on the Share Bus for Li-ion batteries is proposed in this paper. The equalization circuit has the following advantages. Firstly, the Share Bus topology can achieve simultaneous equalization of all batteries, thereby leading to a high balancing speed. Secondly, the proposed circuit adopts zero-voltage control technology which can reduce the power loss of the MOSFET. Besides, the number of switches in the circuit is equal to the number of the battery cells. So the proposed circuit has a lower cost. An experiment was carried out with 12-cell batteries to verify the feasibility of the method.