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Why can't GM put the VOLT out with no battery or one that is as small as possible to make it work. It can run on the generator at 50 mpg(Should be more then 50 mpg because of less weight of battery).

This would be great for a few reasons.
1.Great gas mileage.
2.They don't have to wait for the batteries just make the car so
that when batteries are better and cheaper you can go buy
one and have it put in your car.
3.The volt would be cheaper(much smaller battery).
 

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Why can't GM put the VOLT out with no battery ...
IF GM puts out the car without the battery, why call it the Volt?
It would just be a plain old car with an internal combustion engine connected to an electric drive rather than a traditional mechanical one.
That arrangement would be only slightly more efficient, thus your fuel savings would be minimal.
If GM sold the car as such, I would'nt even bother with it.
I'd buy a Prius instead.
 

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The only reason the range extender gets ~50mpg is because it runs at a constant rpm at peak efficiency. The battery supplies the variable output needed for driving.

That does get me thinking though. I wonder if it's feasible to have an ICE generator directly powering an electric motor and how that setup would compare to a standard drive train efficiency-wise.

e: Nevermind that's how diesel trains work
 

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Battery Magic

Why can't GM put the VOLT out with no battery or one that is as small as possible to make it work.
The peak power required by the Volt is about 3X that of the genset. For equal performance without a battery, the size of the genset would have to be increased by 3X. One of the advantages of the battery is that you can use the energy during car deceleration, which is lost wo an energy retreival and storage mechanism, to charge the battery and extend mileage. Without it your mpg drops. A simulation shows that the All Electric Range (AER) of the Volt drops from 40 to 30 miles (3/4 the mileage) during the EPA city cycle (lots of starts and stops) without regen. The output from a generator is noisy and has voltage transients. The battery smoothes this output. No battery compromises the reliability of the powertrain electronics. The Prius requires a 5 kWhr battery to do its magic. The volt would need something of the same size to retain the advantages of a battery in a hybrid with minimal AER.
 

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The advantage of the '5 kwh' battery like the Prius is lower cost. Please note there are a lot of technologies that can drastically increase the efficiency of the gasoline engine. GM can't do everything at once, so it will take a few model years. For example, VW (or Audi) has a diesel that hyper milers get 80+ mpg out of. Regardless of electrical only range, a serial hybrid is a MUCH simpler design than a parallel hybrid (Prius). Long term it will be much, much cheaper to build and maintain.
 
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