get yourself some "quick disconnects for the battery" there are a variety out there. ya may have to hunt some, for a type that will fit your machine better.
you could always wire in a red/black cables directly to the battery terminals (may need to get new ends for battery cables), and get yourself a generic plug. many battery tenders out there. come with 2 pig tails, one with alligator clips, and another for sticking it into a cigarette lighter outlet on a vehicle. cut the ends off one of the pig tails and just permentally wire it in. and use some zip ties to hold it in place.