What is the basic principle of the Li-ion Battery Pack Protection Board?

The Li-ion Battery Pack Protection Board is the charge and discharge protection for the Li-ion Series Battery Pack. When fully charged, it can ensure that the voltage difference between each individual battery is less than the set value (general ± 20mV) to achieve the battery pack each individual battery is charged, effectively improving the charging effect under the series charging mode; At the same time, the overvoltage, undervoltage, overcurrent, short circuit and overtemperature state of each individual battery in the battery pack are detected to protect and prolong the service life of the lithium-ion battery pack. Undervoltage protection prevents each individual battery from being damaged by overdischarge during discharge.

A typical Li-ion battery pack protection board usually includes a control IC, MOS switch, resistor, capacitor and auxiliary devices such as FUSE, PTC, NTC, ID, memory and so on. Among them, the control IC controls the MOS switch under normal conditions so that the cell and the external circuit are connected, and when the cell voltage or circuit current exceeds the specified value, it immediately controls the MOS switch off to protect the safety of the cell.

1, Overcharge detection voltage: In the normal state, Vdd gradually increases from high level to low normal voltage between VDD-VSS to the CO end.

2, overcharge release voltage: in the charging state, Vdd gradually decreases towards the CO end from low level to high voltage between VDD-VSS.

3, overdischarge detection voltage: normally, Vdd gradually decreases to the DO terminal from high level to low normal voltage between VDD-VSS.

4, overdischarge enable voltage: in overdischarge state, Vdd gradually increases to DO terminal from low level to high voltage between VDD-VSS.

5, overcurrent 1 detection voltage: in the normal state, VM gradually rises from high level to low normal VM-VSS voltage until DO.

Lithium Batteries,

Lithium Polymer Battery,

Lithium Iron Phosphate Battery

6, overcurrent 2 detection voltage: in the normal state, VM from OV at a speed greater than 1ms and less than 4ms to the DO terminal from high level to low voltage between VM-VSS.

7, load short-circuit detection voltage: in the normal state, VM starts with OV to 1μ Over 50 The speed below S rises to the DO terminal from high level to low voltage between VM-VSS.

8, charger detected voltage: in the overdischarge state, the VM gradually decreases from OV to DO from low level to high voltage between VM-VSS.