Self Charging Electric Car?

An alternator doesn’t care how it spins in order to produce electricity. Why should we?

For a year I have thought about using the wind resistance while driving to turn, like fan blades which would turn an alternator. At best it could produce enough apms to extend the milage range of the batteries for city driving. Open road/highway driving could not only power the car but help charge it’s batteries. This is a quick and easy solution but there may be several problems with noise, rain and snow.

A better way is to take the rotation of the rear wheels/axle to turn an alternator. The enviromental impact alone would make testing this idea out worth it.

Mike the Electronic Technician

What you are contemplating is a perpetual motion machine. Please see for an explanation. If you can make one that works, you will become extremely rich.

Whenever you add an alternator/generator that runs off the car’s momentum, whether it be wind based or on the axle, it will cost more in resistance than it gives you in electrical power.

It doesn’t matter whether you are using the engine or the wheels/axles to turn the alternator. The energy is coming from the engine. Ride a bicycle that is equipped with a generator to power the headlight. As soon as you put the generator against the wheel you can feel the resistance. Railroad passenger cars used to have a 32 volt electrical system where the batteries were charged by a generator driven by a belt from the axles. The railroad found it wss more efficient to generate the electrical power in the engine.

When you put the blades on your car to generate energy, you are putting a drag on the car and you will lose engergy rather than gain energy. Unfortunately, you don’t get something for nothing.

I fully agree…
I bike and sail and I can tell you there are NO free lunches when it comes to using wind power generated from your own motion. The loss of energy in conversion from one source to another is not worth the effort. Now using wind power from a static position is a different story.

The only ‘free energy’ available on cars is the energy lost when you put on the brakes. All hybrids and EVs capture that by switching the electric motors into generators and recharging the batteries when you press the brake pedal. If you need more stopping power, the regular brakes are applied.

another source of “free” energy is turbo charging. a supercharger or procharger runs off the engine directly, but a turbo runs off of exhaust velocity. though not electricity, its used to make more power and increase MPG’s slightly.

Doesn’t a turbo charger create resistance a motor must overcome? Doesn’t it keep the exhaust from flowing freely and make the engine work harder?

I think if you are looking for “free energy,” regenerative braking and solar energy are your best choices. Just about anything else creates resistance the motor must overcome.

As others have said this idea can’t really go anywhere, but I have often thought that one might line all interstates with miniature guardrail wind turbines that would be activated by the air movement created by passing vehicles. That wouldn’t do your own vehicle any good but it would re-capture some of that energy. I’m also sure, however, that it wouldn’t be even close to cost effective.

Wouldn’t that create ever so slightly more wind resistance for the cars to overcome? You wouldn’t create energy, you’d just move it around.

I have no idea. I just spend a lot of time on interstates and think about anything from the meaning of life to whether or not I remembered to put any beer in the fridge for when I got home.

I do believe, however, that contemporary turbine blades work not by having the air “push” them, but by being designed like airplane wings. The air flows past them with a higher pressure on one side - at least that is how I have been led to understand it. So I can’t imagine a whole lot of back pressure being created.

A turbocharger doesn’t “make” any energy (other than however much energy the blowing air has),it just uses a little bit of the engine’s power to create conditions which allow the engine to run more efficiently. The extra power you’re getting is coming not from the turbocharger physically making the engine go faster, but from the engine running at 25% efficiency with boost instead of 22% (or whatever the true figures may be) without.

This is also why people who shout “perpetual motion!” at the HHO device hucksters aren’t exactly correct, because the usual claim isn’t that the device generates more power, but that it makes the regular engine more efficient, which in general terms is no different than a turbocharger. The energy used versus increase in efficiency numbers just happen to work with a turbocharger and not with an HHO device.

Wouldn’t that create ever so slightly more wind resistance for the cars to overcome?

To answer your question, Tardis, ask yourself if the leaves on the ground that get blown by passing cars create extra resistance for the cars. I don’t think they do, especially since they usually don’t blow around until the car is already past the spot. If you run past a balloon sitting on the floor, it will move after you pass it, but it won’t actually create any resistance for you. The resistance is caused by the air moving around you, or your car. The turbulence you leave in your wake doesn’t create any resistance.