The solar panel charges the internal batteries during the day. At night the solar security light illuminates when it detects motion in the same way as regular mains powered security lights.
How do I install a solar security light?
Solar security lights are very easy to install in comparison with mains powered security lights. Simply attach the light unit to the wall, taking care to think about the location of the solar panel. Ideally the solar panel should be south facing and in the sun for as much of the day as possible - midday sun is always best!