The lithium battery protection plate is the charge and discharge protection for the series lithium battery pack. When fully charged, it can ensure that the voltage difference between each single battery is less than the set value (general ± 20mV) to realize the equal charging of each battery pack, effectively improving the charging effect under the series charging mode; At the same time, the state of overvoltage, undervoltage, overcurrent, short circuit and overtemperature of each battery in the battery pack is detected to protect and extend the battery life. The undervoltage protection prevents the battery from being damaged by overdischarge when discharging each single battery. The finished lithium battery is mainly composed of two parts, lithium battery core and protection plate, lithium battery core is mainly composed of positive plate, diaphragm, negative plate, electrolyte; Positive plate, diaphragm, negative plate winding or stacking, packaging, perfusion electrolyte, packaging is made of cell, lithium battery protection board many people do not know, lithium battery protection board, as the name suggests is used to protect lithium battery, lithium battery protection board is to protect the battery but put, but charged, but flow, and output short-circuit protection.