When the headset is powering on, the red LED flashes rapidly indicating the battery level.
4 flashes = High, 70 ~ 100%
3 flashes = Medium, 30 ~ 70%
2 flashes = Low, 0 ~ 30%
Voice Prompt Indicator
When you power on the headset, keep pressing the Center Button and the (+) Button simultaneously for about 5 seconds. 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 a voice prompt for the battery level indication.