EK-YT-21 BMS is a new generation of BMS specially developed for mini-cars, light energy storage station and communication base station. The product integrates collecting, controlling and communication together, which has the functions of voltage/temperature collection, balance, charge-discharge control, SOC estimation, and alarm. EK-YT-21 BMS is composed of EK-YT-M2124 module which has functions of system management and information monitoring. The EK-YT-21 system through the current sensor to collect current data, determine the charging and discharging state, complete working current measurement, charge and discharge control of the battery pack, comprehensive utilization of the battery data to do SOC estimation and discrete evaluation.