BMS (Battery Management System) - a battery management system that is designed to monitor the status of batteries, control the process of charging / discharging the battery, etc.
Five, four or three batteries (18650) can be connected to this module at the same time. By default, the circuit is assembled to work with 5 batteries. To switch to a 3 or 4 battery mode, it is necessary to solder a jumper or SMD resistor marked "0" in the appropriate places (see photo). Also, the features of this controller are: protection against short circuit (short circuit) and protection against overdischarge (overcharge). Also a feature of the module is to turn off the power supply for the batteries when reaching the maximum capacity of all batteries (balancing). The maximum operating current of this BMS controller is 80 A, and the quiescent current reaches up to 40 μA. The battery charge is switched off when the voltage reaches 4.25 - 4.35 V, and the discharge when the voltage drops to 2.3 - 3.0 V.
This module of the battery charge-discharge controller has 8 outputs:
B +: positive pole of the battery, load and charge
B-: battery negative pole
B4: midpoint assembly of 1 and 2 batteries
B3: mid-point assembly of 2 and 3 batteries
B2: mid-point assembly of 3 and 4 batteries
B1: mid-point assembly of 4 and 5 batteries
P-: negative discharge terminal at current, more than 60A
C-: negative terminal charge / discharge at current less than 60A
On the board there is an LED indication of the charge of each segment of the battery (continuous burning) and balancing of individual segments (blinking).
If the maximum permissible value of the supply voltage is exceeded, the charge controller activates the "protection" mode. In order to restore the module, it is necessary to re-apply voltage to the input of the BMS board or wait a while until the charge controller automatically disables the protection.
The voltage range of the module is from 12.0 to 21.0 V, depending on the number of segments: 3S / 4S / 5S.