evatech has the RC lawnmower conversion kits for alternators
we also have a build site
http://www.honkernet.net/AHS/departm..._Lawnmower.htm
we use the 24 volt system with speed controlers from robotpower.. they use a battery eliminator circuit that controls the flow to the wheelchair motors.. evatechs is a 24 volt system that uses an alternator.. carlos is cool.. call him