I love my Roomba, but one of the places where it could be improved is the battery. Mine has already given up the ghost and it’s only a couple of years old. I didn’t want to spend US$50 on a replacement battery, and I knew that lots of people had hacked their Roombas, so I figured they’d played with the batteries as well. I was right! RoombaReview.com hosts a little tutorial on how to take apart your Roomba’s battery and replace its innards with NiMH C-cells intended for R/C cars.
Hardware Beyond the Hype