A new battery management system for li-ion battery packs

This paper proposes a new battery management system (BMS) for Li-ion battery packs of multi cells in series. The proposed BMS employs a master-slave control mode. The whole system is composed of a master processor and a string of slave manager cells (SMCs). Each battery cell corresponds to an SMC. Differing from the conventional BMS, the proposed one has a novel method for data acquisition and communication. An SMC communicates with adjacent counterparts to transfer the battery information as well as the commands from the master processor. The nethermost SMC communicates with the master processor directly. This method allows the battery management chips to be implemented in a standard CMOS process. A testing chip was fabricated in the CSMC 0.5mum 5V N-well CMOS process. The testing results verified the proposed method for data communication and the whole system functioned well.