You can check the battery level by the LED indicator.
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%
Or by Voice Prompt indicator.
When you power on the headset, keep pressing the Center Button and the (+) Button simultaneously for about 3 seconds until you hear three, high toned 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 a voice prompt for the battery level indication.