From Approximate Engineering:
It’s well known that robots crave power. In this case, however, we’re talking about electricity rather than world domination (whether your robot craves world domination is between you and the robot, but in any case it’ll need electricity to get anywhere). This post is a quick overview of how I’ve powered my PiWars robots – there may be other options, but this is a set of parts and connections that will definitely work!
Each Friday is PiDay here at Adafruit! Be sure to check out our posts, tutorials and new Raspberry Pi related products. Adafruit has the largest and best selection of Raspberry Pi accessories and all the code & tutorials to get you up and running in no time!
Source: Adafruit – Robotics