three important subsystems of the battery management system

　　(1) SOC estimation function

　　It is very important to accurately estimate the change of SOC value, and its algorithm is one of the core competitiveness of related enterprises. The estimation accuracy of SOC is high, and for the same amount of battery, it can have a higher cruising range. Therefore, high-precision SOC estimation can effectively reduce the required battery cost.

　　(2) Thermal management function

　　Thermal management mainly includes determining the battery's optimal operating temperature range, battery thermal field calculation and temperature prediction, heat transfer medium selection, thermal management system heat dissipation structure design and fan prediction stability selection. Ensure that the battery is working within the proper temperature range and reduce the temperature difference between the battery modules.

　　(3) Balance control function

　　Balance control is divided into active balance and passive balance. Active balancing is to balance the capacity or voltage differences between the battery cells during the charging, discharging, or placing of the battery pack to eliminate various inconsistencies within the battery. The balancing method is mainly based on passive balancing, and the parallel shunt energy consumption resistance of the single battery is adopted, and the balancing work can only be done during the charging process.