Well this is not much of a shop project, but my boy who is a little under 2 1/2 got a one hell of a boost in his little electric power wheels 4 wheeler. He kinda got bored with it because it would barely move faster than he could walk. Well it takes a small rechargable 6volt battery. I took that out and rigged it up with one of my 18volt dewalt cordless drill batteries. That little sucker moves! He has to lean forward when he hits the go button or it will wheely and he'll fall off the back. If he starts out on gravel he'll throw a little roost. He's even learned how to whip shitties in the driveway with it. Now I can't keep him off of it and I can barely keep up with recharging batteries for it. They'll last for about a solid half hour of riding. I thought it might smoke the little motor but he's been riding it like this for about 2 weeks.