Battery management system protection

- Mar 22, 2018-

A BMS may protect its battery by preventing it from operating outside its safe operating area, such as:

  • Over-current (may be different in charging and discharging modes)

  • Over-voltage (during charging)

  • Under-voltage (during discharging), especially important for lead–acid and Li-ion cells

  • Over-temperature

  • Under-temperature

  • Over-pressure (NiMH batteries)

  • Ground fault or leakage current detection (system monitoring that the high voltage battery is electrically disconnected from any conductive object touchable to use like vehicle body)

The BMS may prevent operation outside the battery's safe operating area by:

  • Including an internal switch (such as a relay or solid state device) which is opened if the battery is operated outside its safe operating area

  • Requesting the devices to which the battery is connected to reduce or even terminate using the battery.

  • Actively controlling the environment, such as through heaters, fans, air conditioning or liquid cooling