I have a Casio Pro-Trek tough solar which is a great watch in its own respect (aside from the fact that it needs a new watch band, but it won't take a standard band - crap). I was checking out some G-shock solars, and next to them, some Casios with a 10 year battery...then a thought occurred to me: Just how long would the cell in a solar powered watch last? My guess is that it charges up a capacitor, and my experience with similar type of capacitors in computers is that 10 years is about the most to expect out of them before they can no longer hold a charge. If this is the case, then perhaps a G-shock with a 10 year battery would be a better choice? Does anyone know for certain?