The Rechargeable AA Battery USB drive concept was designed and conceived by Wonchul Hwang. The idea is a memory stick that doubles as a rechargeable battery. This is a great on-the-go gadget for if you need to back up files and power a remote control or flashlight at the same time.
This would be ideal for students or employees who regularly carry a flash drive with them. In this instance, the battery USB drive would work primarily as file storage and the AA battery would be for emergencies. To turn from a USB to a battery, one would twist the device until the USB emerged. LED lights that look like plus signs would indicate how fully the battery is charged.