You can check the battery level in two different ways when the headset is powering on.
Via LED indicator
When the headset is powering on, the red LED flashes rapidly indicating the batter y level.
4 flashes = High, 70~100%
3 flashes = Medium, 30~70%
2 flashes = Low, 0~30%
Via Voice Prompt Indicator
When you power on the headset, keep pressing the Center Button and the (+) Button simultaneously for several seconds until you hear high tone triple beeps. Then you will hear a voice prompt indicating the battery level. However, if you release the buttons as soon as the headset turns on, you will not hear the
voice prompt giving the battery level indication.