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Old 08-14-2009, 01:59 PM   #34 (permalink)
jamesqf
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Quote:
Originally Posted by NeilBlanchard View Post
The Volt is what is called a serial hybrid (though the folks at GM want to call it an "extended range EV"). This means the electric motor pushes the car by it self, and the ICE is used to charge the battery -- this is similar to how electric/diesel trains work.
Not quite the way it works, at least from descriptions I've read. (And from basic engineering, not the way it should work for best results.) The engine/generator drives the electric motor directly (as in a diesel-electric locomotive). If the engine produces more power than needed, then the extra can recharge the battery (as can energy from regenerative braking).

The point is that there are losses in the battery charging process, so for best efficiency you don't want your gasoline engine to recharge it unnecessarily. So if you are planning a trip beyond what can be done on the battery alone, you wouldn't want to run the battery down, then switch to the gas engine. Instead, the engine should come on when the battery is partly drained, and provide a constant power output, with the remaining battery in reserve for acceleration or hill climbing.
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