In the 1890s, electric bicycles were documented within various U.S. patents. For example, on 31 December 1895, Ogden Bolton Jr. was granted U.S. Patent 552,271 for a battery-powered bicycle with "6-pole brush-and-commutator direct current (DC) hub motor mounted in the rear wheel". There were no gears and the motor could draw up to 100 amperes (A) from a 10-volt battery.[5]

For many bikes, battery range is more important that total power (because they're all pretty powerful). You want a bike that delivers a range long enough for your rides at the power levels you want. Most e-bikes will have three to five levels of assist kicking in anywhere from 25 percent of you pedal power to 200 percent boost. Consider how fast the battery takes to recharge, especially if you'll be using your bike for long commutes.
It’s only available in one frame size but the low top tube, adjustable seat and more upright riding position make it comfortable for people of different heights. The low-ride cargo rack and smaller (20-inch) rear wheel lower the center of gravity making the bike easier to maneuver. This is a workhorse of a bike that could easily replace a second car for most day-to-day necessities.
On the other end of the pricing spectrum (although not as high-end as possible) falls the Riese & Muller lines. The Nevo line, which features a Bosch motor, hydraulic disc brakes and speeds up to 28 mph also has a roughly $5,000 sticker (a variety of models allows for a cheaper price). Using a carbon belt and Nuvinci grip shifter, maintenance worries lessen. The German-made premium models are hand made to specifications and comfort reigns supreme.
E-bikes mostly use motors and battery options from a few major suppliers: Bosch, Yamaha, Shimano, and Brose. A few other brands exist, but are less reliable or powerful. Some, like the Yamaha system, have more torque and others are quieter. But generally all four make good options. Look for motor output (in watts) which will give you an idea of total power. But watt hours (Wh) is perhaps a better figure to use—it takes into account battery output and life to give a truer reflection of power.