The built in crystalline solar module charges the battery during the day. The light source is a long lasting yellow LED which is under the solar module and this illuminates the candle underneath it. The LED has a flicker effect which make the candle look as if it is really burning. The light switches on automatically at night and switches off automatically during the day. Technical details Crystalline solar module 1 x yellow LED with subtle flickering effect Maximum lighting time 6 hours Sturdy plastic metal design Size approx 13 x 26 cm Rechargeable battery mignon NiMh 1.2 V, 300 mAh Comes supplied with rechargeable battery .