Have any of you considered solar power for charging your devices? If you have, the Portable Multi-Purpose Solar Charger from Brando looks like it might be a pretty good (although somewhat bulky and expensive) way to accomplish that task. It can output 24V, 22V, 16V@4A and 5V@500mA power. High power capacity is provided by a 20,000mAh ~ 3.7V batteries array. I tried the Solio Hybrid charger this past Spring without a lot of success, but I’m always open to trying other alternative power source options.