Electric driven, Gas charging

[FormulaTwo]

I have been thinking lately.
The huge downfall to electric cars is the cost of batteries, and their range.
So what if you could install a generator, that would charge the batteries. While the actual motor that drove the car was electric?

Lets say a person were to install a generator such as this....

into an EV.

It seems to me like you could charge the batteries anytime you wanted through the generator. Or whenever they batteries got down to 50%. etc.....

the run time on a generator like the one pictured is 12 hours at 50% output.
Producing 2900 watts/ 24.2 amps

It seems like a car setup like this would be more efficient. Less gas would be used, to do the same amount of work.

Anyone have any thoughts on this?

Tried to google it, found this......



1898
The German Dr. Ferdinand Porsche, at age 23, built his first car, the Lohner Electric Chaise. It was the world's first front-wheel-drive. Porsche's second car was a hybrid, using an internal combustion engine to spin a generator that provided power to electric motors located in the wheel hubs. On battery alone, the car could travel nearly forty miles.

pretty sad how "far" we have come

[Matt Timion]

This was done in 1979 by a man named David Arthurs in 1979.

http://www.motherearthnews.com/Alter...id_Electic_Car

[JanGeo]

Buy a Prius... No seriously do the math on the fuel used to run the generator at that output and then the energy needed to power an electric car per mile and calculate how much fuel you burned running the generator and see what your mileage would be.

[rh77]

I could see a generator as a great supplement to the existing system, such as helping the current hybrid system retain charge, but the energy used in driving under batteries alone would drain them quickly and require more ICE input (even if the generator worked at full-tilt; moreover, most generators are horrible emitters, like lawn mowers (which the exception of some Honda generators that have a crude catalytic converter). You also have to factor-in the added weight.

But whose to say you can't have one that runs on CNG that's "Philled" once a week to reduce fuel consumption and wire it in (complexly). They make natural gas generators that work quite well.

RH77

[JanGeo]

Same problem with CNG and Propane - both gasses have lower energy per liter values than gasoline and are more complicated to store requiring pressurized tanks etc. and a filling station plus road tax issues. The only practical use of ICE being added would be to extend range in a pure EV - the only cool thing to do would be to retool a motor for more efficient operation at a resulting power level that will probably be less but more efficiently burn gasoline than is possible with conventional engines.

[cfg83]

Hi FormulaTwo -

Originally Posted by FormulaTwo

I have been thinking lately.
The huge downfall to electric cars is the cost of batteries, and their range.
So what if you could install a generator, that would charge the batteries. While the actual motor that drove the car was electric?

...snip...

Actually, what you just wrote is the original definition of a hybrid. When the term hybrid was first created to describe gas/electric autos, the ICE was supposed to be disconnected from the drivertrain. It's only purpose was to run at a set RPM as needed to keep the batteries charged. In this way, you could design a small engine that was *optimized* for one RPM. An engine designed for one RPM can be made to combust in a super clean manner.

Todays ICE of all RPMs is the emissions master of none, so to speak .

That's why I am against the blanket judgement that the Toyota Prius is superior to the Honda Insight in terms of technology, aka the "my hybrid is better than your hybrid debate". If you want to be accurate, neither technology meets the original definition of a hybrid. Whatever gets you from point A to point B with the highest mileage and lowest emissions wins.

CarloSW2

[omgwtfbyobbq]

Likw JanGeo said, if you do the math on most low end, lightweight, gas generators, you'll find that they convert gas to electricity inefficienctly (~700-800g/kwh) because they are built for portability and light weight. As you get into the more expensive, $3-5k range, you can pick up portable diesel gensets that weigh in at 150-250lbs and use 300-400g/kwh, which is much better than most gasoline cars, but still iffy when you consider the cost of swapping a diesel engine into your car. So, the limit is generator efficiency, not battery charging or electric motor efficiency.

If you're serious about this I'd suggest looking into generator efficiency wrt engine load. Here is an example of a very DIY job, with the generator using roughly 300g/kwh, which is pretty much half of what most people use currently cruising at 55mph on the freeway. Of course we still have battery charging/electric motor losses, but otoh we have idling/extremely low speed engine operation in autos, so I'm guessing a properly setup system would just about double the average Joe's average mpg.

It's probably doable, and like Matt said, has been done. It's just not viable with most off the shelf gensets... Just like pure EVs aren't viable with 10ah NiMHs. Coincidence? Probably. But it's still interesting.

[JanGeo]

The Prius and the Insite are setup a bit differently so to compare the two is not very simple if you consider that the Prius is a parallel/series hybrid designed to run the engine with low emmissions where as the Insite is a simple parallel hybrid.