Full Charge for a S2:

If the battery on your S2 is completely drained, it will take about 5 hours to fully charge your projector. Please note the projector must be turned off in order for the battery to charge back up.

The LED indicator on the side of the projector will be red when the projector is charging or receiving power. Once the projector has been fully charged, the LED indicator will turn green.

The S2 can be used continuously when plugged into power but it will not charge when in use.