Do you know the working principle of lithium battery protection board?

Principle of Lithium Battery Protection Board Lithium batteries (rechargeable) need to be maintained due to their own characteristics. Since the material of the lithium battery itself determines that it cannot be charged, discharged, overcharged, short-circuited, or charged and discharged under ultra-high temperature, the lithium battery package always has an exquisite maintenance board and a current fuse. The maintenance function of lithium battery is generally completed by the cooperation of maintenance circuit boards, PTC and other current devices. The repair board is composed of electronic circuits. Under the environment of -40℃~+85℃, the battery voltage and charging and discharging circuit current can be accurately monitored at any time, and the on and off of the current circuit can be controlled in time. PTC prevents serious damage to the battery at high temperatures. Lithium battery maintenance boards generally include control ICs, MOS switches, resistors, capacitors and auxiliary device fuses, PTC, NTC, ID, memory, etc. When everything is normal, the control IC controls the MOS switch so that the battery and the external circuit can be connected. When the battery voltage or circuit current exceeds the specified value, it controls the MOS switch to turn off immediately to keep the battery safe. Under normal conditions of the maintenance board, the Vdd level is high, the Vss and VM levels are low, and the DO and CO levels are high. When any parameter of Vdd, Vss and VM changes, the level of DO or CO will also change. 1. Overcharge detection voltage: Under normal circumstances, Vdd gradually rises from the high level of the CO terminal to the voltage between the low voltage Vdd-vss. 2. Exempt from overcharge voltage: In the charging state, Vdd gradually drops to the voltage between the CO terminal Vdd-vss, from low to high. 3. Over-discharge detection voltage: Under normal circumstances, Vdd will gradually decrease from high level to low level under the use of Vdd-vss voltage. 4. Overdischarge immunity voltage: In the case of overdischarge, Vdd gradually rises to the voltage between Vdd-vss at the DO terminal, from low to high. 5. Overcurrent 1. Check the voltage: Under normal circumstances, VM gradually rises to DO, from high level to low level and then to VM-vss voltage. 6. Overcurrent 2. Detected voltage: Under normal circumstances, the speed of VM rising from OV to DO terminal is greater than 1ms and less than 4ms, and VM-vss changes from high level to low level. 7. Load short-circuit detection voltage: Under normal circumstances, at the DO terminal, the voltage between vm-vss changes from high level to low level at a speed of 1S on OV and 50S under OV. 8. Charger detection voltage: In the case of over-discharge, the voltage between vm-vss gradually decreases from low level to high level, and gradually decreases from OV to DO. 9. Current consumption during normal operation: Under normal circumstances, the current of the VDD terminal (IDD) is the current consumption during normal operation. 10. Overdischarge current consumption: In the discharging state, the current (IDD) flowing through the VDD pin is the overdischarge current consumption. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous post: Analysis of the characteristics of lithium iron phosphate batteries