Why won't an alternator on an electric vehicle work?

Question

I came across this very same question and I was actually surprised at the very rude and sarcastic responses so please think carefully before you post a response.

The thought process here is NOT to create something that is perpetual motion, but to assist the current usage within the electric vehicle which could then increase the car's efficiency and longevity.

What I'm asking here is would adding an alternator or generator to an electric vehicle increase it's range, ability to handle more load, more onboard electronics like air conditioning and so forth?

(and please don't lecture me on the conservation of energy theory. Because something is widely accepted does not make it perfect, infallible, and law. )

Answer 1

Yes, over the edge is correct. Whenever you slow a modern electric vehicle, some of the kinetic energy is converted to electricity which is,in turn converted into chemical potential energy in the battery. But you usually would not use an alternator to do that. The trick is that the very motors that drive the vehicle can be electronaically adapted, instant to instant, to generate electricity. It would be inefficient to have extra devices when you can get a double use out of the ones you already have, especailly since each new device adds weight.

But in principle, your idea is sound. Not that you would generate electricity when the vehicle was providing power - that would always be a losing game: - you would always have to spend more energy that you would get. (There are well proved laws of nature that make it impossible to have a 100% efficient conversion.) But you definitely want to generate electricity when it is time to reduce the kinetic energy of the vehicle - when you want to slow down.

By being able to recover some of the energy that would otherwise be lost in braking, either to slow down, on as in the case of a steep descent, to keep from speeding up, you would definitely increase the range of the vehicle.

Answer 2

The alternator /generator has to run off of the belts that are turned by the motor, thus consuming more power/gasoline for whatever you want to be powered by the extra alternator/generator.

EDIT--You meant an electric vehicle? That's even more absurd. Alternators /generators transform mechanical energy to electrical energy with a loss of energy along the way. If you already have an electric vehicle, WHY would you want to put in a mechanical device to produce electrical energy at a loss???

Answer 3

No one can answer this question without lecturing you on conservation of energy. Which is not a theory, it is a proven fact.

But I'll try. It won't work. Without getting into the math and physics which you won't understand, all I can say is it won't work.

Try it if you want. You will find that you just waste energy.

I'll give it one more try.

Alternators are perhaps 80% efficient. So to output 10kw, you need an input (mechanical work) of 12 kw. This mechanical work comes from the electric motor, which is about 90% efficient, so it takes 13kw.

So we have 13 kw used to produce 10 kw. You lost 3 kw. You did not gain any power, you lost power, which appears as heat, in the motor, the alternator, the wires, etc. Which can never be regained.

.

Answer 4

Most electric and hybrid-electric cars do through regenerative braking systems, and by using momentum when slowing down to generate electricity.

When you apply the brakes in an electric/hybrid-electric car, in addition to the traditional friction-based braking, the electric motor turns into a generator, creating electricity to recharge the battery. Also, any time you lift the accelerator, the car's momentum is converted to energy.

Note: Regenerative braking by itself is not enough to stop a car quickly; the car still needs a traditional friction-based braking system.