The lithium battery pack consists of three parts: the battery cell, the maintenance board and the shell.
The battery cell is composed of a lithium battery pack, and the maintenance board is used to charge and discharge the lithium battery pack in series; when fully charged, it can ensure that the voltage difference between the individual cells is less than the set value (generally ±20mV), complete The equal charging of each single cell of the battery pack effectively improves the charging function in the series charging mode; at the same time, the overvoltage, undervoltage, overcurrent, short circuit and overtemperature conditions of each single cell in the battery pack are detected, and the maintenance and extension Battery life; under-voltage maintenance prevents each single battery from being damaged due to over-discharge when it is discharged.

There are parallel and series circuits in lithium battery cells. Because of the simple series circuit, because of the differences in capacity, internal resistance, attenuation characteristics, self-discharge and other functions between single lithium batteries, when charging lithium batteries in series.
The single lithium battery with the smallest capacity in the battery pack will be fully charged at the earliest. At this moment, other lithium batteries are not fully charged. If the series charging continues, the fully charged single lithium battery may be charged.