generators and starters
For you guys that think it would be easier to convert an old generator there are plenty of them on ebay. Another idea might be to convert one that is already a starter generator. The old Cub Cadet lawn and garden tractors used a combination starter generator. It was used to start the tractor and then used to charge the battery. I see on ebay where Yamaha is also using something like that on their golf carts. Some of them are as cheap as $40 for a good used one.