I love not having to lug out all the vacuum stuff so much that I probably am going to try and build my own battery pack for this when the current one cr*ps out, which it will. They are using very low grade nimh batteries, it is fairly easy to build a pack using better ones, but that will probably cost $25 or so in cells. Fortunately, I wound up with 2 motor boxes, so I figure I can mix and match for at least one or two more seasons. This thing was so close.....