Placing your batteries in a box on the front seems okay, but my favorite way is to use panniers (not pictured in avatar)
http://www.arkel.com has the strongest racks (with pivot) for full suspension bikes like yours. I'm always hauling beer or groceries on my bike and absolutely need storage space. Panniers have low center of gravity and hide the batteries from view. Just my two cents because they've worked well for three years, and are safe from rain.
edit: "Arkel" link is not correct, "arkel panniers" works though.




