The main function of PCM, is to provide overcharge protection, over discharge protection, short circuit protection, over current protection, over temperature protection and equalization protection for lithium batteries.
Lithium PCM usually includes control IC, MOS switch and auxiliary devices such as NTC and ID memory. Among them, the control IC, under all normal conditions, controls the MOS switch on, so that the core and external circuit communication, and when the core voltage or circuit current exceeds the specified value, it immediately controls the MOS switch off, to protect the safety of the core.
For LiFePO4 cell, the standard voltage is 3.2V, the minimum overdischarge is 2.5V, the maximum overcharge is 3.65V. For Li-ion Cell, the standard voltage is 3.7V, the minimum overdischarge is 2.8V, the maximum overcharge is 4.25V. And any one string will be protected when it reaches the protection value.
When choosing a lithium PCM, two main parameters needing to care, the voltage and the discharge current. The basic parameters of the protection board determine the battery voltage lithium battery in use, will be on the working voltage of the loading , and the capacity of the series-parallel combination, the single lithium cells assembly into a lithium battery pack, such as electric vehicles common 48V, 60V, etc..