Headphones and charging case are equipped with built-in batteries. Before using for the first time, make sure the headphones are fully charged.
Charging case: plug the power cable to micro-USB port. Plug the other end of the cable to standard 5V USB connector. During charging, the charging case indicator next to the micro-USB port will flash red. If charging doesn't start, remove and reconnect the power cable. When the full charge of the case is reached, the indicator will light steadily in red. Remove the power cable from micro-USB port.
Headphones: charging the headphones doesn't require the cable. Just put the headphones in the case and press power button inside the case. When the indicator on the headphones lights up red, and at the case - white, charging the headphones will start. If charging doesn't start, insert them into the case. When the headphones are fully charged, the red indicator turns off. In this case, the charging case will automatically turn off.
Before set the headphones in the case, make sure that the ear pads are correctly fixed on the headphones and don't interfere with their charging, and the charging contacts on the headphones and/or in the case are not dirty.