I love the idea of electric cars. I want one. Right now they are very hard to get in Canada (where I am) plus the price is a bit of an ouch but I can get over those two hurdles. The big draw back to me is the limited range. Most cars that I have seen listed as “on the market now” vehicles have a range of about 200km (130 miles) before you must recharge them. For those living in the city and STAYING in the city that’s fine, more than fine, but what about road trips? A person cannot be expected to stop after 3 hours of driving to recharge for 8-10 hours. That is just not reasonable.
I did not post this to complain. I posted because I have a few ideas on how to solve this problem, though I am no engineer. I was wondering any one on this forum has heard about any EV companies tackling this problem currently or even if it has already been solved by somebody.
My ideas go like this. Why not have the vehicle charging it’s own batteries while in motion? You could have air vents “a la ram air system” directing forced air to wind type turbines, or solar panels on the roof, or some kind of turbine system attached to the drive shaft even. None of these systems would necessarily "solve the electricity consumption problem but it would make the power last longer especially if used together in some way.
So does any one know if any EV companies are actually doing this, using the vehicles on motion to generate energy?
Welcome to the forums!
To answer your question:
The laws of physics to not permit you to harness the energy that you are putting into the system. It would be like convering electrical to mechanical to electrical. You would have to have a more than 100% efficiant driveline to get any electricity from this, which is impossible. However, there are other ways to get over the range thing. The EV that i am building will have a 200 Mile range which is good for almost everything, but i will want to take road trips with it as well. My solution is a diesel generator with a 30 kw generator attached to it. The unit will be enclosed in a metal container with a hitch reciever on it. I will then be able to attach this unit to the back of my car using the hitch. This diesel generator will run off of bio-diesel, regualr diesel and used cooking oil. The benifit of moutning it directly to the car is that i will be able to store it easier (remove it when i do not need it), as well as not having the woos of pulling a trailer: registration, back up, parking, stability at high speeds etc. I am only at the design phases of the generator system, but the numbers seem to work so it is just a matter of building it!
-Leif
Space
You might want to look up perpetual motion(which is impossible). It should have a good explanation of why what you purpose will not work.
Another simpler answer for road trips is a rental car. If you only take 3-4 road trips per year (a fair average I think) then this solution is still economical. There are a couple of advantages to this. Most of the EVs are going to be on the small size, which is fine for a commuter but for a 4-15hr trip I find them a little cramped. Renting a larger sedan/ wagon/ mini van can give you a lot more space and the price difference (between sizes) is usually minimal. Second it is just nice to drive something different once in a while. Compare the rental price of such a car to the purchase price of a generator and do the math. Even if you are fiscally at the break even point, there is also the hassle factor of dealing with and maintaining the generator.
Lazlow
Lazlow’s solution is the best, and here’s another reason why - if a thief breaks into the vehicle to get the head unit, it’s the renter’s problem not yours. You’re not going to be down for days trying to get a window replacement.
You know, one could integrate some porwer generation into the braking system of the car. If your gonna lose some energy (while braking), you might as well harness it. Some sort of two stage breaking system.
It is called regenerative braking. Fairly easy to do with AC motors but more difficult with DC motors.
Thanks for every bodies input on this topic. The simple solution of renting a car for trips is a wise one. So filled with common sense it escaped me.
But on a purely technical level I wanted to respond to the idea that I was suggesting a perpetual motion machine. I was not. I know that energy cannot be created or destroyed. What I was proposing was a way to augment the battery stores through means such as solar panels, small wind turbines and the breaking system(an idea I had heard a little about). The car would eventually run out of power but later than if one was only using previously stored energy. What I don’t know is can a battery in use store energy or would one require a dual battery system (one running the car and one storing energy which could later be switched)? Such a system would not necessarily be using the energy of the running car to create energy but instead the environment that a car in motion would be in, so to speak.
Is that still impossible?
perpetual motion is possible 
just depends on how its setup.
I’m doing something similar to what Lectrol is doing, but my generator will be under the hood. ~40hp diesel mounted crossways with a heavy belt driving a generator mounted behind it, where the firewall starts to angle towards the floorboards. The controller will either be mounted above the engine, or in the back by the battery packs, the motor will be mounted in what was the transmission tunnel, driving the factory driveshaft and rear axle through a toroidal drive (hopefully).
This system is known as a serial hybrid.
FWIW, wind turbines won’t do anything other than add to the drag. What little bit of power you get from them will be more than countered by the power needed to turn them, not to mention the wind resistance of the rigging and other etcetera that goes with wind power. Solar would help a little, but until the next generation panel become available, you will have a heavy and fragile car, again without a whole lot of gain.
You can get range out of straight electric with the newer LiIon batteries, if you’re made of money.
For the time being, though, the quick and dirty answers are on-board generator, or rental cars.
And FEUS- I think that he wants to stay within the confines of gravity and atmosphere, so there will need to be some sort of energy input to counter the resistance of motion from friction. 
The idea of spacemaurader is good but difficult to achieve, at least at this time.
Many EV manufacturers have already thought about his issue. That of course doesnt mean there is nothing more to do regarding the range, but we have to become realistic. The energy produced by a solar panel or by ram air is simply too little to extend the range. There have been trials with this method on a TWIKE but the increased weight of the vehicle (due to the solarpanel) reduced the range again. A very promising car comes from Switzerland. Its called ‘Solartaxi’. Its a prototype and is currently on a trip around the world. The car which is powered by a ZEBRA battery has an attached trailer with a solar panel. Not sure how much it actually does increase the range but I believe its up to 50%. The car and its trailer has reached road certification by the swiss authorities. The message of the project is to show ‘it’s possible’.
More about it can be found on http://www.solartaxi.com
A forum for the solartaxi and other eco-cars here: http://ecocarforum.com