Im not sure how long you will be away from power (few hours/day vs weeks on end)

I frequently find myself away from power for 1-3 days at a time. For me a halo brand charger/battery works great. About the size of a fat lipstick, I charge it via wall socket or the laptop USB port. It holds its charge for weeks on end if not used. Charges my iphone 100% fairly quickly; for times I cant wait I just connect the halo device to my iphone and talk/email uninterrupted. Will charge tablet too. I get about 4-5 full phone charges on my device before I must recharge the device again (admit that I tend to re-charge it when it gets to about 1/3 capacity since I never know where I will be any given day)

They make different sizes/capacity. They aren't expensive. In the disaster sector I work in most of us use these type of compact devices. Some use one or two lipstick style, some go for the "deck of cards" size. We just throw them in our backpack/fanny pack or pockets. Also great for power outages during storms at home when the entire family calls to check in on us and ends up yapping lol

try QVC, radiochack, best buy or (my favorite) monoprice dot com
here is a quick link-
http://www.qvc.com/Electronics.categ...305_qvc%20halo