The lithium battery protective plate is the charge and discharge protection for lithium battery pack in series; After full charge, ensure the voltage difference between each battery is less than the set value (±20mV) commonly, realize each battery for balanced charge, effectively improve the charging effect of charging mode in series and parallel; At the same time, detect every single battery in the battery pack, including overvoltage, under voltage, over current, short circuit, over temperature condition, so as to protect and extend the service life of the battery; Under-voltage protection makes every single battery in discharge avoid damaged because of over discharge when use batteryThe finished product lithium battery of two main parts, and protection of lithium battery core board, lithium battery core is mainly composed of positive plate, diaphragm, negative plate, electrolyte composition; Positive plate, diaphragm, negative plate coil or cascade, packing and infusion liquid electrolyte, after encapsulation make batteries.