I have always liked the idea of rechargeable batteries, because they only cost a fraction of what they’re worth as normal batteries, but now I see a different innovation that I had never thought of, even it was obvious: putting solar cells onto the rechargeable battery, and having it charged for free, and most importantly, anywhere!
Knut Karlsen, a blogger from Norway, thought of this thing as he knew the Norwegian IFE (Institute for Energy Technology) was tinkering with flexible solar cells, worked with them and requested a sample. Then he glued the pieces of solar cells onto some rechargeables and made some simple connections (one with silver paste, and the other with some flat cable from an old Canon camera).
The inventor didn’t tell us how long it took for the batteries to fill, but he mentioned he was thinking of a better one that has a charging controller and a LED attached, though this would require smaller batteries to fit into the C-cell battery form. The solar cells were of 1.8V and the batteries of 1.5V, so the match was close.
Knut offered some photos of his innovation, that you may watch below: