Lithium backpack for Arduino MEGA

The Mega Lithium BackPack is an Open Source Hardware battery shield for the Arduino Mega that snaps to the back of the board, and provides around 15-27 hours of battery power to circuits built with the Arduino Mega (depending on the circuit). It gives a 3.3 volt, 5 volt, ground, and battery capacity testing signal that can be plugged into the Analog input port to test how much battery power is left.

The BackPack sells for $48.

Introducing the Mega BackPack, a battery for the Arduino Mega