Connect the battery to the speed controller and the throttle. Follow the instructions included with the kit to connect each part. Typically, you’ll only need to plug the connector on the speed controller into the connector on the battery, then repeat the process for the throttle. Be sure not to touch the battery wires together, as this could create a dangerous spark! 
We've also released our first native 72V battery pack in a conventional downtube battery casing, assembled using the high power Samsung 27100 40T cells so that even with the small 8Ah capacity it is able to deliver 40-50A continuous currents. This is an ideal battery for fast and sporty offroad ebike builds, allowing powerful performance without the weight or complexity of most 72V setups (either two 36V packs in series or a large triangle frame battery).
By 1898 a rear wheel drive electric bicycle, which used a driving belt along the outside edge of the wheel was patented by Mathew J. Steffens. Also, the 1899 Template:US Patent by John Schnepf depicted a rear wheel friction “roller-wheel” style drive electric bicycle. Schnepf's invention was later re-examined and expanded in 1969 by G.A. Wood Jr. with his Template:US Patent. Wood’s device used 4 fractional horsepower motors; each rated less than ½ horsepower and connected through a series of gears.
On the other hand, the battery doesn’t lock into the bike, which means you can’t just leave it on your bike when you park at the bike rack. Anyone could walk by and simply remove your battery. That seems like an oversight to me, though perhaps the designers assumed that such a small battery would just be easy to take with you. And it is. My wife could probably lose this battery in her purse.