What is a lithium battery protection board? What is the principle of a mobile phone lithium battery protection board

We all know that the lithium battery we use is actually composed of several small internal lithium batteries connected in parallel. There are several plastic-like plates separating them in the gaps between the internal lithium batteries. These small plastic boards are actually lithium battery protection boards. In fact, the lithium battery protection board is not made of plastic. It is composed of several non-conductive fiberboards wrapped with a layer of oil. We all know that oil is not conductive. This is the reason why the lithium battery protection board can isolate several lithium batteries and prevent short circuits in the circuit. Secondly, we talked about the lithium battery protection board also has the function of protecting the battery and guarding against battery overcharge. When the external power supply continues to charge the battery quickly, the lithium battery protection board will be used for protection. When the internal power of the lithium battery reaches the saturation level, the internal circuit of the lithium battery protection board will automatically cut off the external fast charging power supply. So that the external power source cannot enter the battery. This is also the principle that the lithium battery protection board protects the battery from overcharge. Lithium battery protection board.jpg Principle of mobile phone lithium battery protection board The protection function of mobile phone lithium battery is usually completed by the protection circuit board and current devices such as PTC or TCO. The protection board is composed of electronic circuits, and the temperature is between -40℃ and +85℃. Under the environment, the voltage of the battery cell and the current of the charging and discharging circuit are accurately monitored at all times, and the on and off of the current circuit is controlled immediately; PTC or TCO is used to guard against severe damage to the battery in a high temperature environment. The protection board usually includes control IC, MOS switch, JEPSUN precision resistor and auxiliary device NTC, ID memory, PCB and so on. 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. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.