Tethered rig for brickpi robot

I’m finally getting back to my robot project for brickPi, but there’s a couple of challenges I need to solve to make “robot tag” reality. I’m planning to use deeplearning4J to train robot recognition using MNIST. At first I’m going to take a couple thousand pictures and use it to train MNIST. Once it’s “functional”, I’ll need to build a square arena for the robots to play tag. I don’t want to use AA batteries for this part of the machine learning since it will run out of juice pretty quickly.

My thought was to use PVC pipes to build a 5’x5’ arena and power the robots directly. This way, it can run for hours and hours and hours without having to change the battery. Has anyone done this?