To qualify as an electric-assisted bicycle under state law they need to have a seat and fully operable pedals for human propulsion, meet federal motor vehicle safety standards, an electric motor that has a power output of not more than 1,000 watts, maximum speed of not more than 20 mph (electric motor and human power combined), disengages or ceases to function when the vehicle’s brakes are applied, two or three wheels
An electric bicycle is a bicycle with an electric motor used to power the vehicle, or to assist with pedaling. In many parts of the world, electric bicycles are classified as bicycles rather than motor vehicles, so they are not subject to the same laws as motor vehicles. Electric bicycles are one type of motorized bicycle. However, electric bicycles are defined separately and treated as a specific vehicle type in many areas of legal jurisdiction.
State laws tend to intermix the source of power as either gasoline ICE or electric drive. This is unfortunate because that neutralizes the environmental advantage of an ebike over an ICE moped. It also misrepresents the contrast in power output levels between an ICE and electric motor system. 50cc gas mopeds/scooters have a 2.5-4 HP rating, while the 20+ mph electric bikes will be 1-2hp, and ride much closer to a normal bicycle compared to a gas powered, 2.5hp moped. E-mopeds will weigh 55-70lbs. Gas mopeds and scooters are typically over 120lbs. E-mopeds are still electric bikes that get valuable power assist from human pedal effort and are usually much quieter.

this bike came really fast. Very surprised at the quality considering the price. It was packaged very well however my fenders had a little kink in it during shipping. I don’t care about that. It is very fast and a solid bike. I own two other Nami electric folding bikes and this is on par with their quality. The only concerns I have is whether or not I’m able to purchase a second battery when this one needs replacement. This is my first electric bike and I’m very impressed with the fun factor.
The batteries are the most important parts of the bike, because (if you don't do any pedaling) they contain all the power that will drive you along. Typical electric bike batteries make about 350–500 W of power (that's about 35–50 volts and 10 amps), which is about a quarter as much as you need to drive an electric toaster. In theory, you could use any kind of battery on a bicycle. In practice, however, you want to use something that stores lots of power without being too heavy—or you'll be using half your power just moving the battery along! That tends to rule out heavy lead-acid batteries like the ones that start cars, though some electric bikes do use them. Lightweight lithium-ion batteries, similar to those used in laptop computers, mobile (cellular) phones, and MP3 players, are now the most popular choice, though they're more expensive than older rechargeable battery technologies such as nickel-cadmium ("nicad"). Typical batteries will give your bicycle a range of 10–40 miles between charges (depending on the terrain) and a top speed of 10–20 mph (which is about the maximum most countries allow for these vehicles by law). You can extend the range by pedaling or free-wheeling some of the time.
Haibike ships the HardNine with 29-inch tires, 180-millimeter hydraulic disc brakes, a 100-millimeter front suspension fork, and a nine-speed Shimano shifting system. The bike’s LCD readout is affixed to the handlebars and displays the current speed, level of charge, remaining range, and current pedal assist mode. The company says the battery can be completely recharged in just four hours, minimizing downtime between rides.