"In a systematic energy flow comparison, a grid-charged battery driving an electric motor will provide mechanical energy about ten times more efficiently than a human eating a typical US diet. For personal travel between 5 and 30 miles per day, the electric bicycle offers the lowest environmental and personal monetary cost, usually without increasing urban travel time"
From Energy,Global Warming, and Electric Bicycles
Energy Flow Analysis with an Emphasis on Personal Transportation
1. Hill Climbing
That may sound obvious, but its the primary advantage. A good electric bike effectively flattens hills, increasing your average speed and eliminating the groan factor when a gradient comes into view. Provided you supply a reasonable amount of effort, you can expect to climb hills of 1 in 10 (10%) on an electric bike with ease, and clear a maximum gradient of 1 in 7 (14%), or much more. In hilly country, the effect is nothing short of miraculous.
It sounds unlikely, doesnt it? But the mathematics is compelling. Think of a steep and busy road, with cars climbing at 30mph. If you previously slogged up the hill at 6mph, but can tackle the same gradient at 12mph with an electric bike, you will see 33% fewer cars, and they will pass you at 18mph rather than 24mph. Or at least, we think thats correct.
Whatever the figures, theres no doubt that an electric bike helps to keep you out of danger. The same general principle applies to road junctions - the faster your acceleration, the sooner you can get out of trouble. And with no need to rush the hills, you wont be tempted to ride downhill at breakneck speed... another useful safety feature.
3. Personal Fitness
Surely a conventional bike will keep you fitter? That, of course, depends how much - if at all - you use it. Research (b) has found that 46% of conventional bikes are used only once or twice a week, with a further 30% being used once a fortnight or even less. By contrast, a recent survey of electric bicycle owners reveals that a third ride their bike at least once a day and 81% use the bike at least once a week (c).
The figures confirm our experience that an electric bike typically gets used at least twice as often as a conventional machine.
Because riding an electric bike is a great deal more enjoyable in hilly country, into strong winds, or when carrying heavy loads, users tend to make better use of them. The motor provides up to half the effort, but more regular use means more exercise for the rider.
4. No Sweat!
Sweat may not be a serious issue when youre out for a leisure ride, but its more important if youre cycling to work. Although some employers are rather grudgingly providing showers and other facilities for cyclists, the great majority have no intention of doing so. An electric bike eliminates the problem at source. In hot weather, its possible to maintain a normal schedule by transferring a bit more load to the electric motor. In colder weather - or if you feel in need of exercise - just throttle back, or turn the motor off.
5. Clean & Green
Electric bikes obviously consume energy, where a conventional bikes does not (provided we ignore the environmental cost of growing and processing food - see below). However, the amount of energy used is very small compared to a moped, motorcycle or car. Besides fuel, the only consumables are the batteries, and these can normally be recycled when life-expired. As for energy use, electric bikes typically consume fuel at an average rate of 100 to 150 watts of electrical energy, against 15,000 or so for a car (admittedly travelling much faster). In terms of fuel consumption, an electric bike achieves about 800-2,000mpg (290 - 700 litres/kilometre) (d). No other commercially available vehicle can match figures of this kind.
If its hard to place these numbers in your own lifestyle, think of a 100 watt electric light bulb burning for an evening - thats enough energy to propel an electrically-assisted bike for 20 to 40 miles...
6. Genuinely Sustainable
Theres a lot of nonsense talked about sustainability in transport, but an electric bicycle can be made genuinely sustainable. Purchase electricity from a green supplier, or generate your own with a roof-mounted windmill or solar panel array (see Solar Power facts), and the vehicles fossil fuel consumption will be zero. Surely a conventional bike does that already? Only if you grow the food you consume whilst riding it. Unfortunately, most modern food production and distribution is so fuel-intensive that the consumption of a typical cyclist is not terribly good.
7. Faster travel
In theory a car can average a high speed, but in practise speed often falls below 10mph in cities. The problem is congestion - motorcycles get around this to some extent, but theyre still confined to the road network. An electric bike can maintain a higher average speed than a bicycle but take advantage of the same network of cycle facilities, giving access to routes that cars and motorcycles cannot reach. The result is often a faster door-to-door journey time than any other mode. And by taking advantage of the uncongested cycle network, but eliminating hills and headwinds, electric bikes are often the most consistent mode of travel.
8. High Resale Value
Electric bikes are new technology, and its early days yet, but the evidence points to a much better resale value than a conventional bike. True, a typical electric bike costs more to buy, at 400-1,000, but it seems youll get most of that back if you sell the machine on.
9. Motorised, but no Red Tape!
You know how it is... MOT due, log book missing, insurance costs rising year on year. Electric bikes are treated just like ordinary bicycles for legislative purposes, so theres absolutely no registration or legislation to worry about. You are of course free to insure the machine if you wish, but theres no compulsion to do anything but enjoy yourself!
As you can see, battery size ranks at the top. With a pair of big car batteries mounted on a trailer, you can go for hours. To double your range, double the size of your battery pack. Many, if not most, e-bikes come with two 12-volt 12Amp-Hour batteries which will take an average rider 8, to maybe 10, miles over moderate terrain. System efficiency ranks at the bottom because most systems are 85% to 95% efficient. The speed you go makes a big difference in how far you go.
All else being equal, range is a function of either:
1) battery capacity (amp-hours X volts) or 2) speed and ease of recharging (high-power chargers provide lots of miles in less than one hour). There is a direct relationship between battery capacity (amp-hrs) and both weight and physical size (total volume). Commonly used sealed lead-acid batteries weigh twice as much a NiMh batteries of the same rating and four time a Lithium Polymer battery. For hill-climbing, expect about 3 feet of elevation gain for every volt-amp-hour. For example, a stock battery pack (two 24-volt, 12 amp-hour batteries) will take you up about 800 feet without pedaling (3 feet X (24 X 12) = 864 feet). Another way to compare performance is the ability to gain elevation.
All else being equal, speed is a function of motor (watt rating) and controller. Most electric bike motors are capable of higher performance characteristics than the controller allows.
[Beware: Some e-bike advertising touts their high-power motors (e.g. 600 watts), but only deliver 400 watts through the controller.]
As for power, consider that Lance Armstrongs average speed over a 2-hour ride is 20.5 mph. Thats just over the legal speed of e-bikes. Lance expended about 1/2 horsepower, or 373 watts, continuously. Most e-bike motors operate continuously in the range of 300 - 600 watts. Most e-bikes, therefore, will make a "Lance Armstrong" of difference in getting you down the road and up the hill!
Regenerative braking doesnt yield much "juice" back into the battery. Even the hi-tech regen on electric automobiles gains less than 10% of the original charge. Therefore, given a choice of either regen or freewheeling, you will generaly get more range with freewheeling - unless you have a hilly route.
Due to the nature of batteries, you can double the battery life expectancy by discharging only 50% of capacity instead of 75%; you get 6 times the battery life at 30% capacity usage per cycle. Think of battery lifetime as having $1000 in the bank and withdrawing a dollar with each 30% disharge cycle -- and withdrawing $10 every time you deeply (85%) discharge the battery.
Rules of Thumb:
There are currently two categories of electric bicycles.
Ebike -The motor is activated by turning the throttle. As such, there is no need for pedaling.
However, one could still pedal at the same time and also decide how much electrical
assistance one wants with the throttle.
Pedelec - Derived from Pedal Electric Cycle. The motor can only be activated as you pedal by
means of a motion or torque sensor.
For a person from 70 - 90 Kgs, it only takes about 150 - 180 watts to move at a speed of 24
km/h on level roads. Therefore a motor of 180 to 250 watts should be more than sufficient and
when you combine your own muscle power to that of the motor.
A good electric bicycle depends on both the motor and the controller working in harmony.
Acceleration, torque, maximum output, assistance factor are the real the judges of what a
good electric bicycle should be.
Our electric bike now uses a Lithium battery with a rating of 24V 8Ah/36V 10Ah,with brushless
hub motor 180-350W. It is intrinsically safe and there is all the protection that is required from
an excellent Battery Management Circuit. The lightness at 3.1 kgs for the entire battery with
casing and circuit. 1 year warranty with 70% retention of original capacity.
Next to nothing. Electric bicycles are the most energy/cost-efficient transport. 1kw will take
about 100 kms C thats about 25 C 50 cents in any country, even the food youll need to that
distance on a regular bike will cost more.
This depends on what the regulations in your country allow. We put in the controls and motor
specifications to meet such requirements. The following regulations for the USA and Europe
The US Senate has passed SR 1156 clearing the way for legal definition of an electric bicycle
in the USA. President Bush has signed this law. The new law will assign the governance of
electric bicycles to the Consumer Product Safety Commission and will define a bicycle that has
two pedals (and is capable of being propelled by those pedals) and an electric motor of no
more than 750 watts, a top speed (on motor only) of 20 mph as a "bicycle"
Pedelecs up to 25km/h (16 mph) and a motor no more than 250 watts rated output are
considered bicycles. Type approval is not required. Applicable November 9th2003 in all EU
The EU directive 2002/24/EC comes in effect on May 9th 2003 and will replace the current Directive 91/61/EEC
There are three secrets to wisely use your electric bicycle: diligent charging, wise assisting and good maintenance.
Diligent Charging: It is good to form a diligent charging habit and it is better to charge your bike
every night. It is harmful to charge while the electric using up. The charger is a "smart" charger
and is designed to protect the battery from overcharging. There is no damage to battery even
under long time charging, but for safety, do not charge more than 24 hours at a time.
Wise Assisting: Our electric electric bicycle can easily drive up bridges and slopes without any
extra force. However, the motor current is very strong in this condition, which greatly
influences battery. Therefore if you want to prolong battery usage,it is good to pedal when
starting out, when heading into a strong wind, or when going uphill.
Good Maintaining: No special maintaining in general condition. Dont let the water cover hub
center in rainy days. Keep full air in your tires. Shut electric lock in the afternoon in time. Send
to our professional repair shop if something is wrong with it.