Bob47
Arlington, TX
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Bumpyroad wrote:smkettner wrote:I think I might be satisfied with 150 to 250 mile range. A small 6000 watt onboard generator might extend the distance significantly if needed. I would love to roll in and fuel up overnight for "free". Of course it would only work for a few years before the parks catch on how much power you are sucking out of that 30 or 50 amp connection.
what is the efficiency of an electric vehicle that needs a fuel powered generator to run?
bumpy 
Actually, not too bad - essentially the internal combustion engine on my Prius is both a fuel powered generator as well as a motive power source (and I do average over 50 mpg even on the highway). While I would agree that the technology isn't currently available for an EV RV, I am happy to see that there are folks looking at ways to solve the technological problems since the likelihood is that the days of affordable fossil fuel are numbered.
The real issue is when will folks wake up to that fact and create a market for efficient diesels, hybrids and EV vehicles. Keep in mind that it took from the dawn of civilization until the end of the civil war for the world's population to reach a billion. At the end of the Korean war it was at 2.5 billion. Today it is approaching 7 billion. The handwriting is on the wall and I, for one, will be happy to use efficient diesel, hybrid or EV technology to continue to travel and enjoy what open space we have left.
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ShapeShifter
Buffalo, NY
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Bumpyroad wrote:what is the efficiency of an electric vehicle that needs a fuel powered generator to run?
bumpy
It can actually be quite good.
Generally, the highest demand for power is during acceleration and climbing hills. While cruising, you are only using a fraction of the power available from the engine. So, in essence, you are carrying around much more engine than you need most of the time.
A typical battery powered electric vehicle has limited range, because of the volume and weight of batteries needed to hold the required energy.
By adding a generator to a battery powered vehicle, you extend the range, because you can recharge while moving. But, the key is that the generator only needs to be sized for the average power consumption, not the peak power like a traditional engine powered vehicle. When there is peak power demand, the batteries make up the shortfall from the generator. When there is low power demand, the excess generator capacity charges the batteries. When there is average power demand, the generator provides the power to move.
The key is that the generator can run at a constant speed where it's most efficient. It doesn't need to speed up and slow down as the vehicle accelerates and brakes, and it doesn't need to idle while sitting at a light.
2007 Holiday Rambler Endeavor 40PDQ
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Jerry B
Ozark Highlands
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LVJ58 wrote:Who knows, but might be interesting to keep an eye on. With new technology emerging on a daily basis, anything could be possible. As I've commented before, if they can build diesel-electric locomotives why can't they build scaled down versions of diesel-electric cars and perhaps even motor homes.
Hi Jim!. I agree this is the way to go. The wheels will be traction motors providing motive force and braking. Simple, reliable and efficient system. Cheers.
Jerry B
1996 Dolphin 535,F-53.
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Bumpyroad
Virginia
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I was not referring to a hybrid vehicle. the post was about using a generator to recharge the batteries, not to move the thing.
bumpy
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ShapeShifter
Buffalo, NY
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Bumpyroad wrote:I was not referring to a hybrid vehicle. the post was about using a generator to recharge the batteries, not to move the thing.
bumpy
That's the point I was discussing. I was assuming using the generator just as a source of power to maintain the batteries, with no mechanical connection to the drivetrain. Sorry for the confusion and not specifically stating it. My comments still stand, it should be more efficient than using a big vehicle engine that is mostly loafing while cruising.
I think it would be most efficient if you size the generator so that it is close to the average power need, so that it is running most of the time. I may be wrong, but I believe a smaller generator running for a longer time at full load, will be more efficient than a larger generator that runs only occasionally at partial load.
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smkettner
Southern CA
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I would size the generator at about half the average power need. I still want to arrive with dead batteries and refuel that electric energy tank for free. This of course would limit the daily travel distance. I think you could get close to double the "mileage" with half battery power and half generator. Energy consumed might even be more but capitalizing on the overnight stay with unmetered electric power would be the benefit.
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Charlie in TX
Cypress
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Many people are still missing the basic issue. Weight vs energy. A lead/acid battery has 50W-hr/kg. Lithium/ion battery has 150W-hr/kg. Gas has 12722W-hr/kg. Diesel will be 30% higher.
Batteries are not a new technology. It is a mature one. There is no great improvement coming along.
Now, a fuel cell is a different story. It will have an energy density (weight vs energy) in the same class as ICE.
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smkettner
Southern CA
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Charlie in TX wrote:Many people are still missing the basic issue. Weight vs energy. A lead/acid battery has 50W-hr/kg. Lithium/ion battery has 150W-hr/kg. Gas has 12722W-hr/kg. Diesel will be 30% higher.
Gas/diesel seem much higher because the other side of the equation is that you add air at about 15 pounds to 1 pound of fuel. So you only have to carry 1/16th of the chemicals that get burned. With batteries you have to carry both sides of the chemical reaction. My point is it might be feasable if you do not need 600+ mile range and 20 minute fill ups. Battery power is far from a slam dunk as far as being practical for most people.
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D.R.Bain
Michigan
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BillTo sell it requires a market ready to buy it. That market was not there in the 80's.
The 4.3L was GMs second attempt at converting a gas engine (remember the Olds 350 diesel?) and was not exactly a raging success! You appear to have been satisfied with the leisurely progress that engine provided, most buyers were not.
And if you had a good one you were lucky.
There was therefore no incentive to continue development of that engine in North America. And none of the "Big Three" was looking at massive overseas sales back then.
Do you remember the Chevette (Isuzu engined) diesel in the 70's? A lot of people do, especially the fact that you could drive OR run the A/C, but not both.
It really was a case of "Three strikes and you're out" as far as GM diesels were concerned.
Have you test drove the Duramax? They are Isuzu designed engines. I love mine it is in my 3/4 ton 4-wheel drive. Gets over 20 mpg towing a small horse trailer even with my foot in it.
Dan, 2007 Damon Daybreak 3270
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BigRabbitMan
Dixon, CA
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D.R.Bain wrote:
Have you test drove the Duramax? They are Isuzu designed engines. I love mine it is in my 3/4 ton 4-wheel drive. Gets over 20 mpg towing a small horse trailer even with my foot in it.
GM has recently announced the release in 2009 of the new 4.5L v-6 Duramax. It will be interesting to see it's fuel economy. HP still over 300hp.
BigRabbitMan & DiamondGal
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