Pru External Battery Trailer Adds 700 Extra Miles of Range to Electric Cars

Is it that difficult to engineer a car to use it's wheel turning energy to power a generator to provide some sustainable energy? Or is there the ability to use the wind generated to power a generator to charge the batteries? As my title states,I am always confused on these matters.

Wow...no thanks....I shouldn't have to tow a huge battery behind me.....I'll wait for super batteries that don't have to be charged until thousands of miles, either that or fusion....until then I'll be using gas.

Allow me to rectify your confusion.

What you are proposing is that, from the motion of the car, one derives energy.

That would be a waste. If you stick your hand out the window, you feel a force pushing back. If you put a wind prop outside a sunroof, it would have a similar effect of increasing the drag on the car. You may generate electricity, but you will also require more energy to move the car at the same speed.

In an ideal environment, the energy lost to having the prop collect energy would be exactly equal to the energy it collects. You would not have generated any energy, only converted the chemical energy is the gas to electrical energy in a battery.

But nothing is ideal. There is always some waste. Therefore, you would require the car to burn more energy, and only get a fraction of it back.

The same goes for "wheels rolling to generate electricity." Energy doesn't magically fount from spinning things; spinning things contain energy. If you want to generate electricity, you need to TAKE the energy from the spinning object. You set up a magnet attatched to the wheels, with a coil of wire. To spin the magnet to generate a current requires energy. If you installed such a thing, it would take away enegy from the car equal to the energy gained, MINUS THE ENERGY LOST TO INEFFICIENCY.

This is how hybrid cars work. They use magnetics for breaks. i.e, it steals the kinetic energy from the car, slowing it down. What they do is they burn gasoline in a normal engine to propel the car; to give the car kinetic energy.

Then, when they want to slow down, they use magnets to break, converting that kinetic energy into electricity, which they can then use to speed up and slow down in place of gasoline. A hybrid car doesn't generate extra energy. It just regains energy that normal cars waste, as their brakes convert kinetic energy into useless heat.

If you no longer want to be "always confused." I would suggest attending middle school or high school science courses. One major componenet to keep in mind is conservation of energy; no free meals. You can't get more energy out of a system than you put it.

Brian144 is correct, citing the 2nd Law of Thermodynamics. Though I would disagree that this is something you learn in middle or high school to any degree of comprehension. You really need a college level class to get into the meat of the concept.

On the article though, this seems like a pretty good idea. If you're going on a long trip, you probably will be bringing luggage and would enjoy the space added anyway. Though I'll agree that it's very cost prohibitive. Hopefully its price would go down over time as more efficient methods of building one are used.

"Hopefully they can find a way to bring costs down, via government subsidies or whatnot." Pathetic PS, why do we have to rely on gov to pay for this? PS you should have stated something like: Hopefully they can find a way to bring costs down through new science and technology, without burdening the taxpayers. This site is called Popular Science NOT Popular Government.

All in all, cool concept, but if I buy this and a Leaf (~$32000), that's $47000 tag. Compared to say a $15000 gasoline vehicle with good gas efficiency I will have $32000 to spend on fuel. At about $1500/year in fuel, I can drive the car for over 21 years (well beyond the life expectancy) . And neither will this trailer last 21 years.

hahahahaha , thats silly , whos problem does this solve ? ridiculous .

@CoolHand032, Basic understanding of energy conservation requires college level courses? Really? REALLY?

Maybe the 10% of reduction in brain size over the past 5000 years does mean we've gotten less intelligent.

That's a rather cool idea. With that you can turn a Nissan Leaf into an 800 mile cruiser--or more. Might be a big expensive though when you can buy an entire car for that much so if you need long range just buy a Nissan Leaf for around town and a Honda Fit for long range. Cost the same as using this trailer. Of course, you can't bring as much along on your trip!

Okay, I'm still trying to wrap my head around that first comment, "Is it really *that* hard to build a perpetual motion machine?" I hope sincerely that that was a joke.

In any case, I love this concept. It's exactly like having my netbook and the optical drive, external storage, speakers, etc. I can plug in when I actually need them. I want a netcar, and this just takes that a bit closer to being the way things work. Modular, sensible, flexible.

The Leaf, combined with the trailer yield the range that's built into every GM Volt -- except that the Volt manages that with less cost, and without the encumberance of a trailer.

Also, why have batteries on board the trailer, if it also has a diesel generator? Why not just a generator trailer, with the output linked to the batteries, which are built into the Leaf? That would mean a substantial reduction in dead weight, plus a savings on batteries.

My undergrad was in physics and now I'm grad school studying electrical engineering. While I don't really see anything wrong with brian114's physics, he's not understanding how the product works. This trailer basically converts your electric vehicle to a "range extended electric vehicle", like the Chevy Volt. It has a small diesel engine to charge the batteries which then can charge your electric car battery. The energy isn't magically created, it comes from the diesel fuel. Also, the trailer actually powers its own wheels so it doesn't cause any extra drag on the car.

@Siromar Did I say that? Maybe the 10% of reduction in brain size over the past 5000 years does mean we've lost the ability to read. Now stop flaming and give some real input.

@tundrasea They probably are trying to keep to the demo of environmentalists who would prefer the use of electricity over fossil fuels. Who knows though that's a good question.

Let's not overlook one important facet of this debate: battery technology is just not at the level of affordability and durability that fossil fuels offer today. While technology is certainly advancing, I fear we may see the cost of high tech batteries on an industrial scale rise due to the limited supply of rare earth metals essential for their manufacture.

http://secinomics.wordpress.com/2010/11/01/rare-earth-rare-opportunity-or-another-bubble/ gives an overview of what factors are causing this constraint (hint: think East)

I had actually conceived of this idea while cooling my heels in the big house. I think the idea of the trailer being self propelled is a little overly complicated but other than that it's cool.

As far as the cost goes perhaps you could rent one to these at your local hertz or your local Chrysler-Fiat Dealer. It's a great way to make an pure electric your only car. I would only need one of these for about 2 days a year. Take the redbox approach, make them ubiquitous, sealed and GPS'd. I think it'd work.

Oh, I really did think of this, no kidding about 4 years ago. What I really want though is the equivalent for my bike. Work is just a little too far otherwise.

Dale

That is a good idea for long trips, but it is way behind the times since we have liquid salt batteries that can hold a super charge, a liquid metal battery that can hold a super charge, and a super charge station that the Japanese developed that is about the size of a backpack and can be placed in your trunk or along side the roadway like gas stations are now. With a super charge battery like the liquid salt or liquid metal and the super charge charging station that can be recharged with solar panels, your electric can go, probably 40 to 50 thousands of miles before you have to replace the battery and a liquid salt or liquid metal battery will cost less than the acid lead battery we have now.

I don't know why most of these science magazines want people to believe that our scientists and engineers are so dumb that they don't know how to build a battery that can barely get you past your neighbors driveway. We have the most advanced battery technology in the world and Japan has the most advanced affordable electric cars in the world. We can couple the two together and have the longest range electric cars in the world.

I agree with brain that is something you learn in middle school and high school seeing as i am still in high school and i knew that. It is more of a common sense thing though.

Also, why not put solar panels in the top of the trailer so they can charge the batteries as you drive but more importantly charge them when you are not in the car. Say you take the car to the mall and then while you are shopping your batteries are being recharged for free (granted you have to pay more initially for the solar panels). Im not really a mall kinda get, just an example.

brian144 offered a fine explanation to always confused. It would have been much better, however, without the disdainful comment added at the end regarding enrolling in a middle- or high-school class. Drop the attitude, please. I'm guessing there are subjects you're not up to speed with, too, brian144.

brian144
If a magnet were part of the driveshaft/axle, then there would be no energy "lost", because the magnet is part of it, and never wasn't there. If you then place a copper wire coil around said driveshaft, electricity would be generated, with very little loss of power to the wheels, and the motor wouldn't use substantially more energy. It's NET energy that is gained, and inefficiency isn't nearly as much as what you make it out to be.

And hybrids/EVs need KERS. It adds about 20kg to the weight of the car, but it stores energy that would have been lost in the battery or flywheel, and since EVs already have a battery, why not. There is no energy used, only useful energy saved from being lost.

I think they should aim for the luxury car market, not the low budget one... 15k over a car worth 100k is not much compared to 15k compared to a car worth 15k...
anyway, just saying...

A practical suggestion is that Nissan have two of these things at every dealer for you to "check out" for that one or two times per year that you really might do it. A more capatilist solution would be for Enterprise to have some to rent out. Maybe the next logical step is for somebody with a little bit of capital to help the envirionment out by having "pru-share" stations around the country, you know" pick it up here, drop it off there"

I think having a small diesel generator mounted on a small trailer would be a far better approach. The generator would kick in only when the state of charge of the battery reached a certain level. It essentially converts the vehicle to a hybrid.

The generator, and fuel tank, could be contained in a very small package that attaches to the vehicle with a straight coupling into a hitch receiver on the vehicle's end. The trailer would have a single swivel wheel under it to allow for turns. This setup would eliminate the headaches one would have backing up a small trailer with a car.

This... Is... Brilliant!!!!! It would be perfect for any person who wanted to save time spent going to the gas station to refill their gas tank, and use that time to play "WOW" that extra 30 minutes of their life that they can't live without, while watching star trek and star wars at the same time while saying, "Luke, I am your father..." into a fan while wearing a replica space suit and Darth Vader helmet!!! But really it is an ingenious idea for anyone who is a bigger traveler. Brilliant! I like.

The laws of thermodynamics basically say that in a closed system:
1) You cannot win - the net energy, potential(stored) and kinetic(movement) of a system can NEVER be more than you started with
2) You cannot break even - you cannot create a 100% thermally efficient system
3) You cannot get out of the game - for man-made systems you can never reach absolute zero entropy.

Thermodynamics say that despite whatever you do to prevent it you WILL run out of gas. The trailer is just giving you a bigger tank, which is what EVs desperately need to be practical.

Wow, this is pretty cool. It would save a lot of money on gas, and electric cars would be able to travel further than ever before. It would be a huge plus for the environment. Cars go Green!!

HAHA well I was going to answer always confused but Brian already beat me to it, and did a great job.

We need more people to start thinking outside the box and demanding that our government let us import some of these cool technologies. What's funny though, is they make diesel engines that get over 100mpg and at 6 gallons of diesel, you can go at least 600 miles. So they're able to power the vehicle as far as the extended trailer in the article, but straight up, without having to convert it to electricity and store it in lead/lithium based batteries. The dirty little secret is our government just doesn't want us driving these cars. With that range, you don't require all the lithium and lead for the batteries. Power the diesel engine on waste vegetable oil or algae oil and you further decrease the carbon footprint. I think compressed air is a much cleaner medium to store energy than batteries. They're making compressed air cars over seas, but do you think we'll ever see them over here in our lifetime? Probably not, God forbid we drive clean vehicles haha.

Think about it, solar, wind or geothermal sources could crank out clean electricity and we can convert it into compressed air and we can drive around with ZERO emissions and no lead or lithium batteries to store the energy.

Until they come up with super efficient capacitors to store electricity, batteries still aren't a very good solution. We're already wondering where we're going to come up with enough lithium for all the batteries we'll need. It's sad that we bail out our auto industries and it's pretty much business as usual, no real innovation. And look at gas prices, they raise them slow enough and people are just like the frog in the pot of hot water. After Katrina, when gas rose to $3/gallon over night, people were freaking out. All summer gas has slowly risen and here we are at $3/gallon but no one cares. The oil and car industries are laughing out our complacency and how quickly we forget.

I don't know that we can get compressed air to a good enough range, though it is very efficient.

I think fuel cells (much like those Bloom has developed) are probably a better option short term. We can run the vehicles on electricity and get much greater efficiency. We can use natural gas and biofuels to power them to reduce carbon emissions and even more conventional fuels which would still benefit from reduced emissions.

1) The extra battery looks ugly. It's all about how the car looks.

2) Wouldn't the extra battery cause more drag and therefore reduce the efficency?

3) You would have to charge the car AND the extra battery at some point and charging both of them would take ALOT LONGER than filling your normal car with gas.

Sorry to rain on your parade guys but the car in the picture is NOT a Nissan Leaf but in fact a Fiat 500 that is available(in EUROPE) with a 1.2L diesel engine that gets 78MPG without a trailer full of batteries thus eliminating a need for them. Now if only Chrysler could get their act together an give us this car with the diesel engine it the US.

I think it's a great idea that this would be available for rent. For most everyday use, you don't need the range. Your electric car is being "filled up" every night. But if you want to take a cross country trip, then this would be great to use. Electric car manufacturers should standardize the connection for such a trailer, so on trailer will work with any electric car. You don't need it every day, so why own it? But having it available for rental would handy for the occasional long trip.

What about using the "powered trailer" idea for other trailers, ie. campers. I am not talking about using batteries, but a generator and driven wheels on the trailer to allow a smaller motor (in the Truck) to pull a trailer. I don't know if it would save money/gas when someone pulls a camper BUT it would save gas when they do not pull a trailer because they would not need as large of a truck to pull a trailer.

why bother with the battery in a trailer. To extend the range of a pure electric vehicle, just put a small diesel or gasoline engine in the trailer with a generator. This would convert the pure electric vehicle into a hybrid.

I love this idea, renting the trailer. I can imagine the EV's of the future stopping at a gas station adjacent to an Interstate and renting one of these FROM THE GAS COMPANY! It would provide a way for the gas companies to continue selling gas as both supply and demand for gas diminishes. It would be expensive gas, but more realistic than paying an extra $15,000 for the trailers when for the vast majority of users never exceed 100 miles in a day.

I begged GM to just use a portable generator in the Volt instead of a permanent engine to drag around all over town. Did they listen? No.

I would think the two easiest attainable sources of renewable energy would be solar panels and wind turbines. at high speed a wind turbine would probably produce more than half the energy you were using.