I've a Citizen solar power watch from around '98 or '99. It still runs, although the cell seems to have aged, and now needs longer in the sun to charge. In th

I've a Citizen solar power watch from around '98 or '99. It still runs, although the cell seems to have aged, and now needs longer in the sun to charge. In the winter when not being worn, I have to leave it on a window ledge to get sufficient charge.