How does the lithium battery protection board work?

The working principle of the lithium battery protection board 1. Overcharge protection and overcharge protection recovery. When the lithium battery is charged and the voltage exceeds the set value VC (4.25-4.35V, the specific overcharge protection voltage depends on the IC), VD1 reverses to change Cout When the battery voltage drops to VCR (3.8-4.1V, the specific overcharge protection recovery voltage depends on IC), Cout becomes high level, T1 is turned on and charging continues, VCR must A fixed value less than VC to prevent frequent jumps. 2. Over-discharge protection and over-discharge protection recovery. When the lithium battery voltage drops to the set value VD (2.3-2.5V, the specific overcharge protection voltage depends on the IC) due to discharge, VD2 reverses and after a short time delay, Make Dout become low level, T2 is cut off, discharging stops, when the accumulator is put into charge, the internal OR gate is turned over and makes T2 turn on again to prepare for the next discharge. 3. Over-current and short-circuit protection. When the charging and discharging loop current of the circuit exceeds the set value or is short-circuited, the short-circuit detection circuit will act to turn off the MOS tube and cut off the current. Due to the chemical characteristics of lithium batteries, in the normal use process, the internal chemical positive reaction of the mutual conversion of electric energy and chemical energy, but under certain conditions, such as overcharging, overdischarging and overcurrent will cause the inside of the battery A chemical side reaction occurs. After the side reaction is intensified, it will seriously affect the performance and service life of the battery, and a large amount of gas may appear, which will cause the internal pressure of the battery to rapidly increase and then explode, causing safety problems. Therefore, all lithium batteries must be protected. The circuit is used to effectively monitor the charging and discharging status of the battery, and to shut off the charging and discharging circuits under certain conditions to prevent damage to the battery. 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: What are the activation methods for electric vehicle lithium battery packs?