Lithium battery guard plate is mainly composed of IC (overvoltage protection) and MOS tube (overcurrent protection), which is used to protect the safety of lithium battery cell devices. Lithium battery is widely used for its high discharge current, low internal resistance, long life and no memory effect
Lithium ion battery in use is strictly forbidden to overcharge, overdischarge, short circuit, otherwise it will make the battery fire, explosion and other fatal shortcomings, so, in the use of rechargeable lithium battery will have a protective plate to protect the safety of the cell.
Analysis of the function of lithium battery protection plate:
1) Overcharge protection function:
The overcharge protection function means that the charger is prohibited to continue charging when it reaches a certain voltage (hereinafter referred to as overcharge detection voltage). That is, the MOS tube that controls overcharge enters the shutdown state and stops charging.
2) Over-release protection function:
The overdischarge protection function stops discharging to the load when the battery voltage becomes low. The MOS tube controlled over discharge is put into the shutdown state, and its discharge is forbidden. This process is just the opposite of the action of overcharge detection.
3) Overcurrent protection function:
The function of overcurrent protection is to stop discharging load when consuming high current. The purpose of this function is to protect the battery and MOS tube and ensure the safety of the battery in working state. After the overcurrent detection, the battery will return to normal after being separated from the load and can be charged or discharged again.
4) Short circuit protection function: short circuit protection principle is the same as 3)
Note:
1, protection IC: is the core of the protection chip. Judge by sampling the battery voltage, issue various instructions to control the MOS tube, and manage the cell.
2, MOS tube: in the protection board circuit mainly play a switch role
