Connect the positive and negative terminals of the display board and connect them to the positive and negative terminals of the tested battery. The digital display shows the real-time battery power.
4S lithium battery, full charge 16.8V
Battery voltage is greater than N X 3.9V, light 4 grid power
The battery voltage is less than N X 3.3V, the power indicator is all off, indicating that the battery is lower than 3.3V, the battery needs to be charged.(N is for the number of battery cells)
The above data is a reference value, there will be about 2% error range.
3 X 4S lithium battery pack power indicator board