The material of the lithium battery determines that it cannot be overcharged, overdischarged, over-current, short-circuited, and ultra-high temperature charged and discharged. Therefore, the lithium battery lithium battery component always appears with a delicate protective plate and a current fuse.

The protection function of lithium batteries is usually completed by the protection circuit board and PTC devices. The protection board composed of electronic circuits monitors the voltage of the battery cell and the current of the charging and discharging circuit in an environment of -40 ℃ to + 85℃ and timely control the on-off of the current loop. The PTC devices prevent bad damage to the battery under high temperature environment.

Ordinary lithium battery protection boards usually contain control ICs, MOS switches, resistors, capacitors, and auxiliary devices FUSE, PTC, NTC, ID, memory, and so on. Among them, the control IC turns the MOS switch on under all normal conditions, so that the cell can be connected to the external circuit, while the cell voltage or loop current exceeds the specified value, it turns the MOS switch off immediately to protect the cell's safety.