The batteries shown above may look like the conventional ones, but they are not. These are the Suncat Solar re-chargeable batteries designed by Knut Karlsen. They consist of a set of old NiMH rechargeable batteries wrapped in a flexible Photo Voltaic cell.
The best part… when the batteries drain out, all you need is to just place them under sunlight and let them charge all by themselves! Pretty neat idea, totally innovative yet very simplistic.