BMS Protect For Lithium Ion Battery Pack 12V 100AH Lifepo4 Battery Pack

The five basic protection functions of lithium-ion batteries

Lithium-ion battery manufacturer lithium-ion battery BMS has functions such as discharge over-current, short-circuit protection, over-current 3A, and delay of 0.2 seconds.

1. Determine the overcurrent and discharge state: In the state of charging and discharging of the intelligent battery, if the detected current exceeds 3A and the delay of 0.2s is still greater than 3A, the overcurrent will be determined. At this time, the protection execution circuit cuts off the discharge protection switch. The condition for removing the protection is to connect the charger. When a connected charger is detected, the overcurrent protection is removed, otherwise the smart battery will always be protected.

2. Determine the conditions for overcharge and discharge: If the battery voltage exceeds 4.2V or the total voltage exceeds 16.8V during battery charging, the battery is judged to be in an overcharged state. At this time, the protection execution circuit cuts off the charging protection switch. In the overcharge release state, the voltage of each battery is less than 4V.

3. Determine the failure of overcharge protection: During charging, if the battery voltage exceeds 4.4V, it is judged that the charging protection function is abnormal. Start the secondary protection circuit and weld the three-terminal fuse.

4. Determine the over-discharge, under-voltage and discharge conditions: during the discharge process, when the voltage of a cell is less than 2.5V, it is determined that the battery is in the over-discharge state, and at this time, the protection execution circuit will cut off the discharge switch to stop discharging. The release condition is that the voltage of all batteries is greater than 3V.

5. Determine the over-temperature protection and release conditions: When the battery voltage temperature exceeds 55°C, determine that the battery is in the over-temperature state. At this time, the protection execution circuit disconnects the charge-discharge protection switch. The release condition is that the battery temperature is below 50°C.