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Perhaps Electric Vehicle's most
striking feature is the fact that they are so
simple, and therefore, reliable.
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Simplicity
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A simple EV can be partitioned into three basic
blocks: batteries, motor, and controller.
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In contrast, the internal
combustion engine has many critical
parts which, if any fail, the car stops
moving.
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Reliability
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The entire propulsion
unit is eliminated and replaced with
electronic components that cannot break
down or lose effectiveness over time.
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“In
internal combustion powered cars, studies have
found that up to 80% of on the road failures are
engine related. Electric powered cars may
eliminate many mechanical breakdowns” (Whitener
41). Although old lead-acid batteries often
required bi-weekly maintenance, new battery
types are completely maintenance free.
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“AC
brushless motors require virtually no
maintenance and can operate at much higher
speeds, enabling more power to be extracted from
a given weight of a motor” (Whitener 34).
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It has been said
that the motor of an electric vehicle can go up
to one million miles, in which case a simple
replacement of bearings would let it drive on
for another million.
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“The useful life of an
electric vehicle [is] anywhere from 25 percent
to 100 percent longer than the corresponding
life of a combustion vehicle” (Perrin 178).
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The following information was
obtained from Jerry Pohorsky, currently President of the Silicon
Valley Chapter of the Electric Auto Association
(EAA). When asked about the reliability and
complexity of an gas car versus an EV, here is
what he pronounced:
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“In an EV, there are no
where near as many moving parts, so not as many
components to fail. This underscores that
simplicity directly implies reliability. A gas
power train may have in excess of 200 moving
parts, each of which is critical for continued
mobility, an EV has only one single moving part
in its propulsion unit: the motor rotor, the
part that connects to the output shaft which in
turn is coupled to the drive train gears.
These gears are of a fixed reduction ratio, not
like an automatic or a manual transmission. No
transmission is needed because of the nearly
constant power capability of the motor over a
huge range of motor speed. In contrast a gas
engine has a narrow power band, and therefore
needs a multi-speed transmission to match this
peak shaped power curve to the wide range of
vehicle road speeds.”
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