Here is my DIY setup and then the Tekkeon setup I bought. Both use regular AA batteries that can be charged. In a pinch you can buy 4 Ever ready cells. The little USB light you can buy for a buck and when not charging your phone you have a nice little IMG][/URL]reading lamp. The trick with DIY is you need a setup that puts out 15-20 VDC then just use a car charger adapter. iPhones are fussy and like to see a apple device feeding them.