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smart65

Electric car with "on board" generator

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I thoought that this might be an interesting discussion to kick off here.How big would a portable 120/240v generator have to be to supply enough continuous energy run an electric car? I'm visualizing one mounted on a small trailer and plugged into the battery's charge circuit. Somewhat similar to a diesel-electric locomotive, where the internal combustion engine generates electricity to run the electric motors which propel the vehicle. It would increase the range of the car, but the fuel economy wouldn't likely be very spectacular. Whatever became of the fuel cell? That would be a natural, if it were developed to the level the original hype promised. Feel free to add your thoughts on this subject.

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Consider that a high-efficiency electric motor running of lithium-ion batteries (think: Tesla) operates at perhaps 88% efficiency. A modern, four-stroke internal-combustion engine in a car operates at roughly 18% efficiency. In other words, you would have to supply roughly five times the input energy potential to a combustion engine just to get the electric drive train to run.

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Overall efficiency will be far lower than if the ICE powered the car directly (ICE loss plus electric loss).....and the ICE used will probably pollute far more than a road legal car engine would, so it's a double hit against air quality and global efficiency. Far better to buy a new Volt if this is the way you want to go.

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Overall efficiency will be far lower than if the ICE powered the car directly (ICE loss plus electric loss).....and the ICE used will probably pollute far more than a road legal car engine would, so it's a double hit against air quality and global efficiency. Far better to buy a new Volt if this is the way you want to go.

The efficiency of an ICE dedicated to a generator would likely be higher than that for one powering the car directly. It would be run at an optimum rpm to maximize efficiency. But there is no question that there are losses. The Jaguar C-X75 uses this principle, but uses gas turbines instead of an ICE to drive the generators that charge the batteries. Such a car can run on batteries when emissions are a problem, but extend range by running the generators when on the open road.

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Wouldn't the on-sale-now Chevy Volt be the standard bearer in the plug-in hybrid segment, beating the Karma to market by a full six months? The Tesla Roadster and Model S are fully-electric vehicles. But calling the Karma more refined than the Model S is a stretch, since the Karma just began deliveries, and uses a Chevy Cobalt SS engine to charge an A123 Systems battery pack that is considered inferior to those made by Tesla. The electric motors are off-the-shelf units as well, unlike the custom Tesla units.

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Wouldn't the on-sale-now Chevy Volt be the standard bearer in the plug-in hybrid segment, beating the Karma to market by a full six months? The Tesla Roadster and Model S are fully-electric vehicles. But calling the Karma more refined than the Model S is a stretch, since the Karma just began deliveries, and uses a Chevy Cobalt SS engine to charge an A123 Systems battery pack that is considered inferior to those made by Tesla. The electric motors are off-the-shelf units as well, unlike the custom Tesla units.

Sorry the model S is a giant leap forward from the roadster, take my comments with a grain of salt for I have never driven either one. I was however under the impression that the volt only charged by plug and that the conventional internal combustion engine propelled the car after the batteries were depleted but did not recharge the batteries.Alan

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This has already been achieved in the Fisker Karma. http://www.fiskerautomotive.com/#!/kar...ions/powertrain This is quite comparable to the tesla but more refined.Alan

Nice car!To be exact though it is more like a luxury Volt than a Tesla - The Tesla is is a Plug-In EV - Fiskar has an onboard motor/generator for extended range. It will be interesting to see which manufacturer woes the buyers. The cars look very similar. Wikipedia notes that Fisker was fired as the designer of the Tesla S for 'substandard work'. Tesla tried to sue him because he incorporated the best of the Tesla S design into the Kharma.Odd to think of Tesla as the establish vendor and Fisker as the upstart! It seems that the smaller more agile companies are bringing better designs to market faster and with less investments than the big three. Will Tesla be the new GM? Interesting times ahead.

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Why would the wheels on it steer?

Because the trailer is not visible to driver due to its small size perhaps?

Posted Image

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As an aside, Toyota announced that they will build the new all-electric RAV here in Ontario. It apparently uses the Tesla power train and will have a range of about 160km (without trailer!)It would be great if the EVs were supplied with a portable generator that could provide enough charge if batteries run out. If it could give you another say 20km, it would save a tow-truck fee!

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I thought it was being built at the former NUMMI (Toyota/GM) plant in Fremont, CA (now known as the Tesla Motors Factory) by Tesla.

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Because the trailer is not visible to driver due to its small size perhaps?

Posted Image

It still doesn't make sense yet. He has a lens to see the trailer.

post-6582-1312677912_thumb.jpg

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The article linked above mentions this:

The micro trailer incorporates intelligent "BackTracker" steering which automatically maintains trailer-to-vehicle alignment during backing to avoid jack-knifing.

Edited by RedDog

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It still doesn't make sense yet. He has a lens to see the trailer.

Reversing a short trailer is particularly difficult, even for those with experience.

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