Research on Li-ion Battery Management System

Battery management system (BMS) is an integral part of the electric vehicle (EV) and the hybrid electric vehicle (HEV).The BMS performs the tasks by integrating one or more of the functions, such as sampling the voltages of the battery cells and the temperatures in the battery module, sampling the voltage of the battery, sampling the current of the battery, as well as cells balancing and determining the state of charge (SOC).In this paper the research of the cells voltage sampling , battery temperature sampling, battery voltage sampling and battery current sampling will be discussed. The method of sampling cells voltage, battery temperature and cells balancing using special integrate circuit (IC) will be presented. This method resolves the problems of sampling cells voltage in Li-ion battery, which has hundreds of cells. We discuss two methods about the result of battery current integral (A_h), and pick out the better via the data of experiment.