Kepler’s “Super Commuter”, with a custom home-built battery pack made from 18650 cells. Part-2 Once you have decided on the voltage, the size, and the shape, I’ll be covering a lot of things in part-2 (click here) , and among them are all the popular methods for connecting the cells to each other, such as spot-welding and wire-bonding (add link to part-2 here)