Onewheel operates in harsh environment, vibrations, shocks, sometimes it rolls on the ground, to make a reliable external battery for onewheel, it calls for a strong casing.
To fit on the top of the fender, we designed the aluminum body to have a curvature, with pocket inside to firmly hold the cells inside, the body is pushed out of a die and extruded into this shape, with the wall thickness of 2mm, coupled with ribs inside, it can take a hard hit and remain its structural integrity.