Two Battery Bionx
The bike is an aluminum Klein mountain. The Bionx battery under the saddle is attached by bolts, washers, and nuts to the sawed off Topeak rack with the quick release handle replaced by a bolt. A Jansport handlebar bag is attached to a homemade second mini handlebar. Deuter makes the frame bag which fits nicely under the main battery. I get about 25 miles per battery, and I have to mechanically switch batteries using a small adjustable wrench.