After using this around the house to get a feel for what it would do, I have not been impressed. At first it was great but now it doesn't seem as effective.I had gotten the SolarFocus SolarDuo for Christmas after looking at them for a while and looking at weight, compatibility with multi batteries and reviews. So far it has been great but I'm just using it sporadically to figure it out so I'm ready in Aug. I believe Santa paid $80ish for it. Compared to the other heavier stuff this looked the way to go. It will charge AA batteries which are used in my headlight, 1 flashlight, gps plus the battery pack charges to AA so they are usable as well. There is an adapter in there that will charge the flat still camera batteries. In short, this 1 item will charge everything I will take on mt that has batteries. (not planned, it just worked out that way)
Another option is the New Trent charger. I have used these and found them much more "backpacker friendly" than solar chargers.
I think mine is the 9000 series and will charge my smart phone 5 times before the battery pack needs re-charging.
The model I have weighs 9oz's and is worth the weight on extended trips.