The finished mobile phone lithium battery is composed of two parts: the battery cell and the battery protection board. The battery cell is used as the power storage part, which determines the quality of the mobile phone lithium battery. The mobile phone battery protection board is used to protect the mobile phone lithium battery from overcharge. Flow, no release, and no short circuit are indispensable for both.

Due to the characteristics of the mobile phone lithium battery itself, it is determined that a protection board with a sampling resistor and a current fuse must appear in the lithium battery component. In normal use, the mobile phone lithium battery undergoes a positive chemical reaction that converts electrical energy and chemical energy. When the mobile phone lithium battery is overcharged, overdischarged, or overcurrent, chemical side reactions may occur inside the battery. After the reaction exceeds the positive reaction, the performance and service life of the mobile phone lithium battery will be seriously affected. Therefore, there must be a mobile phone battery protection board inside the mobile phone lithium battery to monitor the battery status.

The mobile phone lithium battery protection board is composed of protection IC, pcb, capacitor, resistor, diode, triode and MOS tube. The protection IC is the core device in the mobile phone lithium battery protection board, which can control the MOS tube switch in time to protect the performance of the mobile phone lithium battery. The working mechanism of the mobile phone lithium battery protection board is as follows:

Overcharge protection: When the voltage of the battery pack is greater than the maximum value and reaches the protection delay, the protection IC controls the CMOS to turn off the charging circuit.

Over-discharge protection: When the battery pack voltage is less than the maximum value and reaches the protection delay, the protection IC controls the CMOS to turn off the discharge circuit.

Over-current and short-circuit protection: When the output current of the battery pack P+ and P- exceeds the over-current/short-circuit current value and reaches the over-current/short-circuit delay, the control circuit controls the discharge CMOS to turn off the discharge circuit and stop the discharge.

High and low temperature protection: When the temperature sensor reaches the temperature threshold and the protection delay is reached, the control circuit controls to turn off the MOS tube to stop charging and discharging.

The mobile phone lithium battery protection board needs to be tested before it can be used. In the test, a shrapnel micro-needle module that can conduct a large current can be selected as a bridge for connection. It can transmit current in the range of 1-50A, has stable over-current capability and reliable connection capability, and can effectively guarantee the stability of mobile phone lithium battery protection board testing. The shrapnel micro-needle module has a simple manufacturing process, can be customized, and has an average service life of more than 20w times. It can meet the high-frequency test requirements of mobile phone lithium battery protection boards and effectively improve test efficiency. After the test, the performance of the mobile phone lithium battery protection board is guaranteed, and it is safer to use.