BrickPi Power Pack
This is an AA holder for the BrickPi, a Raspberry Pi robotics platform for LEGO Mindstorms. About the BrickPi:  The BrickPi turns your Raspberry Pi into a robot. The system is a board and case that connects LEGO Mindstorms Sensors, motors, and parts to turn your credit card size computer into a LEGO robot. The BrickPi allows you to connect up to 4 NXT Motors and 5 Sensors. It has a 9V battery power source that powers the motors, sensors, and Raspberry Pi, un-tethering the Pi from the wall. Finally, it has a sturdy case with holes that snap with LEGO parts. The brains of a Raspberry Pi joined with the LEGO building system."