Kathy , I had a bottle type originally attached to the rear carry rack . I bolted the rail to the rack then the battery . When I got a bigger battery I made a case out of angled aluminium , insulated on the inside using a realestate sign (plastic) . It cost me about $15 and a day to make . I also thought about mounting it under the front lower bar but didn't like the idea of all the tyre flicking road grime and water over it , also it would need to be secured well . Heres a couple of pics of my first setup and recent .

rick