When the LED blinks red, you should recharge your headphones. Please remove the micro-USB protector and charge the headphones via the supplied USB to AC adapter or PC USB port. It normally takes about 3 hours to fully charge the battery. The LED will stay red when charging and will turn off when charging is complete.
Charging requirement: You can plug our supplied USB cable to your own USB chargers(wall charger/travel charger/car charger,etc) with 5V/500mA-2A or PC USB port. It is OK to use most mobile phone chargers on the market.