basic knowledge of lithium battery protection board

1. The composition of the protection board of lithium battery Its characteristics determine the reason why lithium battery (rechargeable) needs protection. The lithium battery material itself determines that it is not allowed over-charged, over-discharged, overcurrent, short-circuited. The lithium battery’s ultra-high temperature charging and discharging lithium battery components will always appear with an exquisite protection board and a current fuse. The protection circuit board and PTC usually complete the protection function of lithium batteries. The protection board is composed of electronic circuits. It can accurately monitor the battery cell’s voltage and the charging and discharging circuit current under the environment of -40℃ to +85℃. Control the current loop on and off; PTC prevents severe damage to the battery in a high-temperature environment.

The protection board usually includes a control IC, MOS switch, resistor, capacitor, and auxiliary device NTC, ID memory, etc. Among them, the control IC controls the MOS switch to turn on under all normal conditions to make the cell communicate with the external circuit. When the cell voltage or loop current exceeds the specified value, it immediately controls the MOS switch to turn off (tens of milliseconds). Protect the safety of batteries. NTC is the abbreviation of the Negative temperature coefficient, which means a negative temperature coefficient. When the ambient temperature rises, its resistance decreases. The electrical equipment or charging equipment works to respond in time and control internal interruptions to stop charging and discharging. ID memory is often a single-wire interface memory. ID is the abbreviation of Identification, which means Identification, and stores information such as battery type and production date. It can play a role in product traceability and application restrictions.