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Old 10-26-2011, 12:01 AM   #22 (permalink)
jamesqf
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Quote:
Originally Posted by Old Mechanic View Post
Advocates of direct drive electric vehicles state the lack of a transmission makes the vehicle more efficient. In one manner it does that, but in order to recapture several hundred horsepower seconds of energy in a rapid stop, you only have in the neighborhood of 20 revolutions of the wheels to capture the energy. No chemical battery can accept energy at that rate (several hundred kilowatts in a few seconds).
But what fraction of your stops are that rapid?

You do have a good point about the battery charge acceptance rate being a weak link. That's why some people are looking at either ultracapacitors or flywheel systems.
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