Your RPT-02 SOL is powered by light, and more light equals more power. Press the action button and the light indicator shows how much light the headphone receives.

Best charging (3 circles lighted)
its great to be outdoors, and thats also where youll get the most light and most power from powerfoyle.

Good charging (2 circles lighted)
dont let your eyes fool you, there is a lot more light for powerfoyle to harvest into power on a cloudy day than you would imagine.

Some charging (1 circle lighted)
you can still get some charge from the lamps inside your home, so remember to avoid putting your headphones in a drawer when not in use.

No charging (no circles lighted)
no light, no charge, but dont worry about this. Remember that you can charge via usb in case of long periods of no light charge.