Battery management system (BMS) is commonly known as battery nanny or battery steward. The three core functions of BMS are battery cell monitoring, state of charge (SOC) estimation, and cell balancing. During the charging process, the thermal management of the battery, the start and stop of the cooling system of the lithium battery, and the balance between the single batteries are also managed to prevent the danger of overcharging, overdischarging and overheating of the single batteries, Known as the “brain” of the power battery system of new energy vehicles. It is one of the key technologies for the development of electric vehicles to enable electric vehicle power batteries to obtain the best performance and longest service life under various working conditions.