When the Breeze NXT is in use, the light will indicate your device’s current charge. When its current charge is above 3.8 volts, the LED light will be green. When the charge is between 3.5 and 3.8 volts, the light will be blue. When the charge drops mbelow 3.5 volts, the light will then turn red to remind you that it is time to charge your Breeze NXT.