What is a Battery Management System (BMS)?

Battery Management System (BMS) is a circuit that monitors, controls and protects rechargeable batteries. Aim is to ensure safety, efficiency and longevity of the battery. It monitors voltage, current and temperature during the charging and discharging processes. Overcharging and over-discharging are prevented and there is short circuit protection as well. BMS estimates the battery’s state of charge (SOC) and state of health (SOH). It can balance cell voltages, preventing significant differences in voltages between the individual cells comprising the battery. Battery is prevented from operating beyond its safe limits. BMS can disconnect the battery from the load or charger if a problem is detected.

In SOC, the BMS checks how much stored electrical energy is left behind and gives a graphical display. Overall capacity compared to that when it was new is an indicator of SOH of the battery. Balancing the voltage of individual cells improves performance and extends the lifespan of the battery. Potentially dangerous conditions like thermal runaway due to overcharging can be prevented by temperature monitoring and disconnecting the charger when temperature goes beyond the safe limit. BMS optimizes the battery’s performance and ensures consistent power delivery and efficient use of stored energy. Advanced BMS can communicate with a mobile phone or laptop with Bluetooth, so that the details are available remotely.