Not sure how relevant this is to this discussion, but anyways...

My dad used a small (12x4") solar panel charger that he placed on the dash of his truck for years to power his old (and v. large) "bag" phone when he was travelling.  It was enough to keep the phone's battery fully charged even when the phone wasn't plugged into the cig lighter plugin- he said it would still last for hours from the sat phone "trickle charge".  Never harmed the battery either.  

I've heard good reviews from others about the new, rollable solar panel chargers as well- many field crews I know use them to charge laptops, GPS, etc. when  they're in remote areas.

I think it comes down to you get what you pay for (and they're really come down in price!).