I've built a pretty slick mount. It's not so much a box, as there is no cover for the top or sides of the battery. Just a strap to keep it in place. I figure with the battery mounted under the engine, chances are water will saturate the battery and every square inch of the inside of the battery box. I'd rather it be able to easily drain away, so I left the top open. I also mounted the battery sideways, so that both positive and negative are easily accessible from the right side of the bike. In case I ever need a jump. Finally, my box is more of a robust and well-built bash plate, which also happens to hold the battery. It can be used as a jack point, as the entire weight of the bike can be supported on the plate without bending one iota. I'll post pics once I paint the thing.