
Some
errs.. you might have in mind but weren't sure whom to ask....
How
far (mileage) will it go?
Most
EVs today have a maximum range between 60 and 100 miles. This includes
conversions and new cars from the manufacturer. Some vehicles may
do less if they have small battery packs, lots of heavy-draw accessories
like air conditioning, or if they are heavy, or using obsolete components.
Some cars that have been maximized for range may get a little more.
From time to time you will hear about records of several hundred miles
on a single charge. This kind of performance is not yet available
for the average person. These records are generally set in vehicles
using hand-built experimental batteries. Sometimes these batteries
will only last for a dozen charges before they need to be replaced.
Sometimes the battery packs costs many thousands of dollars. And sometimes
the batteries are not in production and commercially available
Battery capacity for range is usually measured in amp/hours. The more
amps you draw as you drive, the less range you have. A higher voltage
car will have better range because amp draw decreases as voltage increases.
The more volts you have, the less amps you use. Range can be improved
dramatically by quality, low-rolling resistance tires with good air
pressure, a good alignment, and good driving habits.
How
long does it take to recharge?
Charging time can vary between 5-6 hours up to 10-12 hours. It depends
on the voltage of the battery pack, and the voltage of the power outlet
servicing the charger. A 96-volt car charging on a 110-volt outlet
will take 10-12 hours. (Note: this is only if it has been driven to
the end of its range and completely discharged. Since most people
only use a fraction of a car's range in a day, their charging time
will be much less.) The same 96-volt car will charge about twice as
fast from a 220-volt outlet. A 120-volt or 144 volt car will take
longer to fully recharge.
Most people can drive their cars for their daily needs, and get a
full recharge at home overnight. Some people also plug their cars
in during the day at work to "top off". As electric cars
become more common, more charging facilities will be available.
The most common charging arrangement on a conversion uses an onboard
charger with an ordinary 110-volt household outlet, because this type
of outlet is most commonly available. It is best to have the outlet
on a separate circuit, with at least 20 amp service.
You will sometimes read about fast charges done in a few minutes.
There is much work being done to develop this technique, but it is
not commercially available yet. This kind of charge requires a very
high voltage source, often 440 volts, or more. It must be carefully
regulated to prevent damage to the batteries. This usually means that
the pack can only be fast-charged to 80% of capacity; more than that
would cause damage.
How many batteries does it use?
A roadworthy, freeway-capable conversion will typically use between
16 and 24 batteries. These are 6-volt batteries that are specially
designed to power electric vehicles, and they are wired together in
series to produce between 96 and 144 volts.
Some race cars use more batteries and higher voltages, because they
are looking for exceptional performance for a racing application.
Many EVs from manufacturers use more batteries and higher voltage
systems. Most conversions use more affordable DC systems, and retain
the transmission to step up the motor rpm to higher speeds.
How long do the batteries last?
The lead acid batteries used in most conversions will last about four
years before needing replacement. An entire pack typically costs $1,000-$1,200.
These are deep discharge traction batteries that are designed to power
a vehicle. Their internal construction is different from the starting
battery in a gas car, or from an RV battery.
How long the pack lasts depends on how it is treated. Batteries that
are left sitting unused for long periods, or left sitting partially
discharged, will have a shorter lifespan. The best thing you can do
for your battery pack is to drive it every day and charge it every
night.
Everything about batteries involves trade-offs. One trade-off is capacity
for lifespan. Some batteries are designed to give higher than normal
range on a single charge. These generally suffer from a reduced lifespan.
Some may last only a year or two, others only a few charges.
Where can I buy one?
Reva
is India's first commercially produced electric car. Reva is a joint
venture between the Bangalore-based Maini group and AEVT Inc of California
in the US. The car can travel 80 km on a single charge of nine units.
The running cost is about 40 paise per km. The Maini group plans to
launch the car across in India in a phased manner.
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