If you haven't used the headphones for a while, the battery may drain completely. If this happens, you need to charge the battery for at least 30 minutes, after which the red light will start to glow.
CHARGING - THE RED LIGHT WON'T TURN ON DURING CHARGING?
If you haven't used the headphones for a while, the battery may drain completely. If this happens, you need to charge the battery for at least 30 minutes, after which the red light will start to glow.