Balancing Check

A project log for Green BMS

Open source Bluetooth Smart Battery Management System

Green-bmsGreen-bms 10/03/2021 at 15:500 Comments

Passive Balancing

Green BMS cell modules carry out the passive balancing. What does it mean?
When the cell reaches the user defined balance threshold, the BMS circuit connects a power resistor of approximately 3 ohms as load to the cell, in order to discharge the cell to help the entire battery pack balancing.

In many BMS systems, the verification of the correct functioning of the balancing circuit is difficult to carry out, because it is necessary to create the unbalanced conditions of the cells, moreover in many cases it is impossible to test the balancing circuit of all the cells.

For this reason, when designing Green BMS, I wanted to add a test function that I think is important: the balancing check.

Balancing Check

The operation is very simple: you have to connect to your battery pack using the Green BMS App and press the button relating to the cell whose balancing circuit you want to test.

At the same time you must check the status of the LEDs on the cell module and make sure that the “Balancing OK” LED lights up and the “Communication LEDs” alternate fast and intermittently.

During balancing test you can also check the real balancing current measuring the voltage drop across the resistors and applying the Ohm’s law formula Ibal = V / R (R=3ohm).

How to perform balancing check video tutorial

In the following video I show you how to perform this test.
bye bye