It totally depends on the amount of time it is used. I have a Dewalt 12v that is about 10 to 12 years old. I might not use it every day but I still have the original batteries it came with and they still hold a charge for a few hours. The drill still works great and I'm sure one of these days...
Depending on how thick the paint is, I would go with some sort of paint stripper, its cheap and it will not harm the metal. If its only a thin layer of paint I would try a paint thinner or nail polish remover, which you might find in the bathroom closet if you wife doesn't mind.
I recently purchased a few older Skil 77 worm drive saws. I noticed that there is a type number on each that is different. I have a type 14 and 15. The 14 has a metal handle that is attached to the motor housing, while the 15 has a plastic handle that is screwed on. I took both apart to repair...