As I've got plenty of low self discharge AA's lying around I like to use them for my projects as well.
So I put together this device to power stuff and projects. It uses a boost regulator from Pololu© which is capable of delivering around 600mA @ 3,3V input. It's a bit less at the AA's 2,8V but I don't care as I won't charge my phone with it, just projects like my SD datalogger.
The LED is a 2mA type.
USB out is glued to the board with epoxy to get stress away from the little solder pins. The board is screwed to a piece of plexiglass I found in my parts drawers :)
Enjoy this project?