Electric Bicycle

An electric bicycle, also known as an e-bike or booster bike, is a bicycle with an integrated electric motor which can be used for propulsion. There are a great variety of e-bikes available worldwide, from e-bikes that only have a small motor to assist the rider's pedal-power  to somewhat more powerful e-bikes which tend closer to moped-style functionality: all, however, retain the ability to bepealled by the rider and are therefore not electric motorcycle. E-bikes use rechargeable batteries and the lighter varieties can travel up to 25 to 32 km/h (16 to 20 mph), depending on the laws of the country in which they are sold, while the more high-powered varieties can often do in excess of 45 km/h (28 mph). In some markets, such as Germany, they are gaining in popularity and taking some market share away from conventional bicycles, while in others, such as China, they are replacing fossil fuel-powered mopeds and small motorcycles.

Pedego Trail Tracker electric bike

Technical

Motors and drivetrains

The two most common types of hub motors used in electric bicycles are brushed and brushless. There are many possible types of electric motorized bicycles with several technologies available, varying in cost and complexity; direct-drive and geared motor units are both used. An electric power-assist system may be added to almost any pedal cycle using chain drive, belt drive, hub motors or friction drive. BLDChub motors are a common modern design with the motor built into the wheel hub itself and the stator fixed solidly to the axle and the magnets attached to and rotating with the wheel. The bicycle wheel hub is the motor. The power levels of motors used are influenced by available legal categories and are often, but not always limited to under 750 watts.

Batteries

E-bikes use rechargeable batteries, electric motors and some form of control. Battery systems in use include sealed lead-acid (SLA), nickel-cadmium (NiCad), nickel-metal hydride (NiMH) or lithium-ion polymers (Li-ion). Batteries vary according to the voltage, total charge capacity (amp hours), weight, the number of charging cycles before performance degrades, and ability to handle over-voltage charging conditions. The energy costs of operating e-bikes are small, but there can be considerable battery replacement costs. The lifespan of a battery pack varies depends on the type of usage. Shallow discharge/recharge cycles will help extend the overall battery life.

Design variations

Not all e-bikes take the form of conventional push-bikes with an incorporated motor, such as the cytronex bicycles which use a small battery disguised as a water botted Some are designed to take the appearance of low capacity motorcycles, but smaller in size and consisting of an electric motor rather than a petrol engine. For example, the Sakura e-bike incorporates a 200 W motor found on standard e-bikes, but also includes plastic cladding, front and rear lights, and a speedometer. It is styled as a modern moped, and is often mistaken for one.

An Electric Pusher Trailer is an e-bike design which incorporates a motor and battery into a trailer that pushes any bicycle. One such trailer is the two-wheeled Ridekick.

Other, rarer designs include that of a 'chopper' styled e-bike, which are designed as more of a 'fun' or 'novelty' e-bike than as a purposeful mobility aid or mode of transport

Electric cargo bikes allow the rider to carry large, heavy items which would be difficult to transport without electric power supplementing the human power input.

Various designs (including those mentioned above) are designed to fit inside most area laws, and the ones that contain pedals can be used on roads in the United Kingdom, among other countries.

Folding e-bikes are also available.

Electric self-balancing unicycles do not conform to e-bike legislation in most countries and therefore cannot be used on the road, but can be utilized in the sidewalk. They are the cheapest electric cycles and used by the last mile commuters.

Country/jurisdiction	Type of e-bike	Speed limit, km/h	mph	Watt limit	Weight limit, kg	Age limit	Demands license plates	Allowed on bike paths	References & footnotes
Australia	pedelec	25	15.5	250	None	None	No	Yes
Australia	hand-throttle	None	None	200	None	None	No	Yes
Canada	hand-throttle	32	20	500	None	Various	No	Varies from municipal by-laws
China	Unknown	30	18.5	None	20	None	No	Yes
European Union Also including:  Norway Not including:  UK	pedelec	25 +10%	17.1	250	None	None	No	Yes
Hong Kong	none allowed	–	–	–	–	–	–	–
Israel	pedelec	25	15.5	250	30	14	No	Yes
Mexico	both	same as motorcycles	same as motorcycles	-	-	15+[17]	Yes	Not
New Zealand	pedelec	None	None	300	None	None	No	Yes
Norway	speed pedelec	45	28	500	None	None	Yes	No
Taiwan	"Sloe Vehicle"	25	16	200	40	None	No	Yes
United Kingdom	pedelec	27.5	17.3	250	40	14	No	Yes
United Kingdom	hand-throttletandem ortricycle	27.5	17.3	250	60	14	No	Yes
United States	hand-throttle	32	20	750	None	None	No	Varies