What role does the protection board play in lithium batteries

The function of the protection board is mainly to protect the cells of the rechargeable battery, and to protect the battery from overcharge protection, overdischarge protection, overcurrent protection, short circuit protection, temperature protection, internal resistance, power consumption, etc. during battery charging. Safety and stability during charging and discharging plays an important role in the performance of the entire battery circuit system. (For example: Lithium batteries are generally composed of batteries, protection boards, and shells, such as mobile phone batteries).

The main function of the protection board:

1) Overcharge protection function: overcharge The protection function means that when a certain voltage (hereinafter referred to as the overcharge detection voltage) is reached, the charger is prohibited from continuing to charge. That is, the MOS tube that controls overcharge is turned off to stop charging.

2) Over-discharge protection function: The over-discharge protection function stops discharging the load when the battery voltage becomes low. Put the MOS tube controlling the over-discharge into the off state and prohibit its discharge. This process is just the opposite of the action during overcharge detection.

3) Over-current protection function: The over-current protection function stops discharging the load when a large current is consumed. The purpose of this function is to protect the battery and MOS tube to ensure the safety of the battery under working conditions . After the over-current detection, the battery will return to the normal state after being separated from the load, and can be recharged or discharged.

4) Short-circuit protection function: The principle of short-circuit protection is the same as

<1> Protection IC: It is the core of the protection chip. Judge by sampling battery voltage, issue various commands to control MOS tube, and manage battery cells.

<2>MOS tube: It mainly acts as a switch in the protection board circuit.