Because the 18650 lithium battery is cylindrical with a diameter of 18mm, the protective plate used is also 17mm in diameter.

Function description of single-section circular protection board:

Battery overcharge protection function: When charging the battery, when the battery voltage reaches the overcharge detection voltage (4.28±0.025V), the protection circuit will act to cut off the charging path to achieve overcharge protection.

Battery over-discharge protection function: when the load is connected and discharged, when the battery voltage drops to the over-discharge voltage (2.3±0.08V), the protection circuit will act to shut off the discharge path to achieve over-discharge protection.

Short-circuit protection function: When the output is short-circuited, the protection circuit will cut off the path after a delay of 320us to achieve short-circuit protection. After the external short-circuit is removed, the circuit can automatically restore the output.

Overcurrent protection function: When the output current exceeds the set maximum current value, the protection circuit will act after a delay of 10ms to cut off the path to achieve overcurrent protection. After disconnecting the external load, the circuit can automatically restore output.