According to Baidu Aibu's inquiry, the seven pins of the lithium battery of the electric wrench are defined as follows:

1, the positive and negative poles of the lithium battery of the electric wrench are used to provide power.

2. The pin of lithium battery of electric wrench is BMS interface, which is used for battery management and protection.

3. The pins of the lithium battery of the electric wrench can transmit data signals to control the charging and discharging of the battery.

4. The pin of the lithium battery of the electric wrench can detect the voltage and temperature of the battery.

For different brands and models of electric wrenches, the specific pin definition will be different. It is recommended to check the product manual before use to obtain accurate pin code definition information.