The main function of the protection board is to protect the cells of the charging battery, maintaining the safety and stability during the charging and discharging process of the lifepo4 battery, and playing an important role in the performance of the entire power battery circuit system. (For example: Lithium batteries are generally composed of cells, protection boards, and shells, such as mobile phone batteries) .

The main functions of the protection board
1) Overcharge protection function:
The overcharge protection function refers to the situation where, 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 transistor that controls overcharge is turned off, and charging is stopped. 

2) Over-discharge protection function:
The over-discharge protection function stops discharging the load when the battery voltage drops. The control MOS transistor enters the off state, prohibiting it from discharging. This process is exactly the opposite of the action during overcharging detection. 

3) Overcurrent Protection Function:
The overcurrent protection function stops discharging the load when a large current is consumed. The purpose of this function is to protect the battery and the MOS transistor, ensuring the safety of the battery during operation. After overcurrent detection, the battery and the load are disconnected and will return to normal, allowing for recharging or discharging. 

4) Short-circuit protection function: The short-circuit protection principle is the same as that in 3). 
Note: 
Protection IC: This is the core of the protection chip. By sampling the battery voltage for judgment, it issues various instructions to control the MOS tube and manages the cell.

MOS tube: In the protection board circuit, it mainly functions as a switch. 
Protection IC: This is the core component for protection. By sampling the battery voltage, it makes judgments and issues various instructions to control the MOS tubes, thereby managing the battery cells. 
MOS tube: In the protection board circuit, it mainly functions as a switch. 
Typical protection board circuit
Take the single-section protection board circuit (DW01+P) as an example: 
Classification of protective 

1. By material classification
1) Gold-plated protective plate - abbreviated as gold plate
Hardware protective plate
Ordinary gold-plated protective plate
Thick-gold plated protective plate
Laminated gold-plated protective plate 
2) Tin-coated protective sheet - abbreviated as tin plate
Ordinary tin plate
Lead-free tin plate 
2. Classification by battery type
1) Single-cell protection board
2) Dual-cell protection board
3) Multi-cell protection board