Lithium battery protection board over-discharge protection control principle

Lithium battery protection board, as its name implies, is a protection board for lithium battery protection. It is the core component of lithium battery, and lithium battery has large discharge current, low internal resistance, long life, no memory effect, etc. It has been widely used by people. Therefore, the lithium battery protection board, as the other key, has been paid more and more attention by people. The lithium battery protection board has the main protection functions of overcharge protection, overdischarge protection, overcurrent protection, and short circuit protection for lithium batteries. Today Chinese Chuangfa will learn the principle of over-discharge protection of lithium battery protection board with everyone.

When the cell is discharged through an external load, the voltage of the cell will slowly decrease, and the DW01 will monitor the cell voltage in real time through the R1 resistor. When the cell voltage drops to about 2.3V DW01 will think that the cell voltage is already in the over-discharge voltage state, and immediately disconnect the output voltage of pin 1, so that the voltage of pin 1 becomes 0V, and the switch tube in 8205A is closed because there is no voltage on pin 5. At this time, the B- of the battery cell and the P- of the protection board are in a disconnected state. That is, the discharge circuit of the battery cell is cut off, and the battery cell will stop discharging. The protection board is in an over-discharge state and has been maintained. After the P and P- of the protection board are indirectly charged with the charging voltage, DW01 will immediately stop the over-discharge state after detecting the charging voltage through B-, and output a high voltage at pin 1 again to turn on the over-discharge control tube in the 8205A. That is, the B- of the battery and the P- of the protection board are reconnected, and the battery is directly charged by the charger.