ebike
FAQ
How to choose an Electric Bike Frequently
Asked Questions
|
| Q.
Who is buying electric bicycles? |
| Electric
commuter bikes are one of the fastest growing
segments of US bicycle sales. In China and
Asian markets bicycles are a much more popular
commuting vehicle than in the US. Europe has
also accepted electric bicycles and scooters.
In the U.S., electric bicycles are just starting
to appear due to the longer distances required
for commuting. Up till now battery technology
has limited power storage ability and bike
range to be unsuitable for US buyers but that
is changing fast now.. Here in the U.S., the
early adopter market for domestic electric
bike sales is primarily the recreational rider.
People who would like to ride farther, faster,
or easier have all expressed an interest in
the electric bicycle. Electric commuting bikes
have even been encouraged by local governments
to get people out of single occupancy cars
to improve polution and traffic congestion
problems. Santa Cruz and San Francisco both
offer electric bike rebate programs for buying
an electric bike kit or electric bicycle.
In Santa Cruz alone about 4000 buyers have
received rebates up to 50 percent of the price
of an electric bicycle. |
| Q.
Why buy an electric bicycle? |
Fitness,
Efficiency, Environmental Improvement, Saves
Money, Have fun at the same time.
There are many reasons why you should consider
an electric bike for recreation or commuting
use. For recreation most of us who dont have
the ability or time to be a competitive cyclist,
an electric bike gives us more opportunity
to exercise without being exhausted at the
end of a ten mile ride. Would you rather struggle
up a hill or effortlessly climb a 10 degree
grade and coast down the other side in half
the time? You can get a workout if you like
but then switch on the motor and cruise home.
On a commute its no fun sitting in an office
swetting at 9am after pedalling for a ten
mile rush to the office to be on time. Switch
on the electric power, take a short cut down
the Alameda bike path and arrive before your
neighbour gets out of heavy traffic. No swetting
and no rush even on a hot day. The feeling
of freedom you get from effortlessly travelling
at a reasonable speed to work on a quiet bike
that costs almost nothing for maintenance
and fuel is something you need to experience.
Do some math on your commute. If you travel
10 miles in traffic to work as most people
do and it takes you 30 minutes or more then
believe it or not you can probably ride to
work on an electric bike in less time. All
it takes is ten minutes in traffic waiting
for freeway access or traffic lights, and
your average speed is below that of an electric
bike, and you cant take short cuts or cruise
to the front of traffic queues like you can
on a bicycle. |
| Q.
How powerful is an electric bike? |
| By
federal law electric bikes are only allowed
to have motors with less than 750 watts power.
Most production electric bikes are in the
300 to 600 watt range. Kits can be bought
to convert your favorite bike from 300 watts
all the way up to a 2000 watt rocket. (see
crystalyte at http://www.bicycles-electric-bikes.com/bicycle_motors.htm
and watch the video at http://www.ebikeproject.com/
its a blast). So it depends, whatever it is
you want you can get it. There are freedoms
granted by federal law for electric bikes
that meet legal requirements such as no license
and insurance. Add these cost savings to only
5 cents a mile power costs and thats a big
difference in your travelling costs to work.
|
| Q.
Can I easily control the motor? Does it feel
safe? |
| The
power from the electric motor is regulated
either manually or proportionally by a controller
to add to the power applied by the rider.
Most imported electric bike controllers apply
power by sensing your peddling speed and applying
proportional power to assist you up hills
and when starting. The power can also be regulated
manually by a twist grip or thumb switch throttle
setting on the handlebars. If you have ridden
a motorcycle then this is going to be like
second nature to you. If you have used a power
tool like a lawn mower or tractor with a speed
control you have also got a good idea how
this feels. Its very easy to regulate and
usually not enough excitement for people who
like speed, unless you already added the 2000
watt motor just for fun. By law electric bikes
remove motor power when you apply the brakes.
It is a safe system for riders without much
experience or older riders without much strength
or endurance who will really benefit from
the added mobility. |
| Q.
What does the extra power feel like? |
|
A normal rider can generate between 100 watts
to 200 watts of power for up to four hours
through the peddles depending on muscle strength
and gear selection. Electric motors can legally
apply up to 750 watts of extra effort. This
exceeds the trained strength of a professional
rider who can apply up to about 400 watts
of power and maybe keep that at 300 watts
for hours. Stop pedalling and the assist power
also immediately drops to zero; start applying
leg power and the assist is helping again.
This is not an electric moped, motor scooter,
or motorcycle…instead it is a bike that
enables you ride at speeds normal to and greater
than a trained athlete through applying 1/4
of the effort or less. Dont expect a 600 watt
motor to raise the front wheel off the ground.
Most designs aim for smooth efficiency and
over 20 mile range at speeds of under 20 mph
where the rider gets some exercise too. Serious
range over 40 miles is attainable but requires
extra batteries. A long range bike will probably
have 48 volt batteries and 17AH capacity.
It is possible on 24 volt bikes to simply
add another 24 volt battery to your system
in parallel with the existing battery. Additional
battery packs are easy to install in a carrier
bag on a rear rack of almost any bike. |
| Q.
How fast can an electric bike go? |
| Electric
bikes are like any other bike with a motor
attached. By law they are regulated to not
go faster than 20 MPH by motor drive alone.
You can peddle or coast downhill as fast as
you feel safe. The motor just cuts out at
20 mph. The electric assist is programmed
to stop assisting at that speed. The aim of
the electric bike is to increase your riding
ability, to let you ride for a longer time…and
take on hills and windy conditions that would
normally be unthinkable. It removes the pain
associated with long rides that we may otherwise
not attempt. |
| Q.
How far will an electric electric bicycle
go? |
The
electric bike motor power (watts) and battery
capacity (in AH) will determine how far it
can travel at any speed. Here is how you can
calculate the approximate range of any bike
with an electric motor attached and get a
reasonable estimate of range.
Step 1. Divide the power of your motor by
the voltage of the battery used to drive it.
For a 600 watt motor on a 24 volt battery
that gives 25 amps current at maximum coming
out of the regulator. On average you may use
half of that half the time. Let say you ride
at half throttle and therefore use an average
of 10-12 amps(half of 25 amps max) from your
battery. 12 amps from a 24 volt battery is
enough to apply about 200 watts of power at
the wheels and achieve a speed of 15 to 20
mph. If you normally ride at about 10 mph
without a motor you can easily ride at 15
- 20 mph with a 200 watt motor helping you.
Step 2 Divide the Power Capacity of your battery
by the current it will supply continuously
and you get the amount of time available from
your battery. If you have a 12 AH battery
that means your battery lasts an hour supplying
12 amps continuously or 2 hours supplying
12 amps half the time. At speeds of 10 - 12
mph which is pretty slow you can expect your
battery to last for over 2 hours and take
you 25 miles or more(12AH /5 amps average
current drain) . At 15- 20 mph you can expect
to drain 12 amps continuously and last maybe
an hour (12AH /12 amps) which takes you 15
miles or more depending on wind and your weight
and how often you brake,
If roads are flat then while your riding its
a question of speed and how many times you
stop that will determine how far you will
go. Rider weight is a key factor here too.
Take a look at this set of graphs and you
can get an idea how human and electric power
performance is related to speed and range.
(Graphs at http://www.ebicibikes.com/) |
| Q.
How long will it take to recharge the electric
bicycle? |
There
are three categories of batteries used in
electric bikes today. Charging times are under
3 hours.
1. The lead acid sealed battery in gel form
is rugged and durable but cheap and heavy.
The 24-Volt maintenance free lead acid batteries
can be completely recharged in four hours
using the integrated microprocessor controlled
battery chargers.
2. The Nickel Metal Hydride batteries that
are the same as your camera batteries on steriods.
These can be recharged in under 3 hours. They
are half the weight of the Lead Acid type
of battery and give better efficiency but
you guessed it, they cost twice as much as
the lead acid batteries.
3. Lithium Ion or Lithium Polymer batteries
are the latest in getting range and durability.
They are very light at about 1/3 the weight
of Lead Acid and provide more capacity and
short charging times. The big deal here is
the price is again double what you pay for
NiMH and four times that of Lead Acid. Thats
a big improvement over what it was a year
ago but still pretty pricey....unless you
need the range. Carrying less dead weight
on a bike by reducing the 20 lbs load of a
lead acid battery to 5 lbs makes a big difference
to the ride as well as efficiency and looks
on the design. |
| Q.
Do the electric batteries have a "memory"
like my cellular phone or cordless drill?
|
| No,
the batteries used on most electric bikes
are not the low cost NiCad batteries found
in many tools, The batteries used in electric
bikes may be partially recharged at any time.
If you go for a ride plug into an outlet with
your battery charger at any time to top up.
It is recommended to charge more rather than
less frequently to prolong the life of any
lead acid battery, including the electric's
deep discharge gel type. If you can charge
up at work, do so rather than letting the
battery drain to a lower level on your way
home. Similar advice for NiMH and Li Polymer
or Li Ion is good. |
| Q.
Are there special motor vehicle or insurance
requirements? |
| The
US Dept. of Transportation has ruled that
the electric bike does not fall into the category
of a motor vehicle. In California, no special
driver's license or license plate is required.
You must be 16 years or older to ride and
a standard bicycle helmet is required. Check
your local community laws for any special
regulations. The electric bicycle may be covered
under your current insurance policy. To determine
coverage, check with your insurance company
or agent. |
| Q.
Is the electric bicycle considered a zero
emission vehicle? |
| Yes.
While some communities define ZEV's as car
replacements only, others are looking for
other ways to help reduce sources of mobile
pollution. The electric bike has qualified
for electric vehicle credits in some communities.
Check with your local environmental management
group for clarification. Every time you take
a short trip on your electric bike rather
than your car, you save making a cold start
that otherwise adds significant pollution
to your environment. |
| Q.
Can I ride the electric bicycle without power
assist? |
| All
electric bikes offer controls you may turn
off entirely. There is no added friction or
drag when pedalling without power assist.
The battery can be quickly removed in less
than 10 seconds on most bikes allowing rides
without the added battery weight. |
| Q.
Can I configure the electric bicycle any way
I want? |
| Most
electric bicycles are designed to conform
to US industry standard component sizes. The
one size fits all "uni-sex" frame
size is used on most designs for riders 5'
to 6'6" tall. Your independent bicycle
dealer can offer an array of bicycle accessories
and upgrades from lights and racks to suspension
forks. Motors and hub drives are now pretty
much interchangeable and not difficult to
do for anyone. Use of tools in most cases
is not required unless you are replacing one
motor or battery type with another technology
which may require installing new connectors
and mounting hardware. |
| Q.
How do I know how much battery energy I have
left in the pack? |
| The
electric system in most bikes incorporates
a battery management system. A sensor can
check the no load voltage and give a good
estimate of remaining charge. |
| Q.
How do I turn the unit on and off? |
| A
key switch on most electric bikes allows you
to turn the system on and off at the battery.
This doesnt stop you peddling so be sure to
carry a physical lock to prevent someone from
taking a joy ride without your permission. |
| Q.
Does the electric bike recharge the batteries
when braking or going downhill? |
| Regenerative
braking is used mainly on more expensive and
heavy electric motorscooters. It is not very
effective on lightweight electric bikes to
warrant the extra expense and is not a common
feature. |
| |
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