The battery life of your QuietComfort headphones averages 80 hours. When the light begins to flash on the control box, you have approximately 8 hours of battery life remaining. The flashing light is an indication that the batteries should be replaced soon (use 2 AAA alkaline batteries—IEC LR03). Be sure to dispose of used batteries properly.
Note: Rechargeable batteries can be used, averaging half the life of alkaline (NimH are recommended). However, the low battery indicator light is not calibrated to these batteries and may not function properly.