Electric car question?

Question

Ok why can't they make some sort of generator that charges the batteries of an electric car while the wheels spin? I have seen a simple generator made from a stationary exercise bike that easily powered multiple light bulbs, now think of the RPMs of the tires of a moving vehicle. Wouldnt you think they could easily make some sort of generator that would be run from the 2 wheels that just roll not the drive wheels? I think they would sell alot more electric cars, I would buy one if I didnt have to charge it after about 250 miles, I could actually drive it on long trips and save alot of money.

Answer 1

It takes energy to spin a generator. That energy comes from the motion of the car. So spinning the generator will cause the car to slow down. The more energy the generator takes, the slower the car goes.

It doesn't matter that the wheels connected to the generator are not the drive wheels. The car slows down anyway, just like it would if you dragged your feet on the ground.

The generator on the exercise bike makes the bike harder to pedal. If a really large generator was attached, you would definitely notice the extra effort it was taking you.

There are laws of physics involved which predict that no matter how cleverly you set this up, the generators will always take more energy than they give back. Sad but true.

Answer 2

The problem is, due to friction, it takes more power to spin the wheels than any power you can make off of it.

Besides, most modern electric cars already have regenerative braking: instead of mechanical brakes, which just converts motion to heat, regen braking turns motor into generator and taps the energy of the wheel to get a little more recharge.

Answer 3

You are talking about a perpetual motion machine. They do not exist. All commercially available electric cars and Hybrids have what is called regenerative braking. They use the energy to decelerate to recharge the batteries. By the way, 250 miles between charges is excellent! Alot of mid size cars and SUV's are lucky to go that far between gasoline stops! And definitely not for 1 cent a mile like electric cars do!

http://phoenixmotorcars.com/faq/index.html#8

http://www.teslamotors.com/index.php?js_enabled=1

Answer 4

You would not gain anything, because all the energy gained would have been spent in gaining it. Read it again, it does make sense.

What you are looking for is a perpetual motion machine. These break the 1st law of thermodynamics, which basically states that you can't cook a potato by putting it in the fridge, nor can you freeze icecream in the oven.

Answer 5

Well, if the generators would be on the wheels and there was no battery used to power it, it would make no difference since the power you gain is exactly proportional to the power you use. You need to move to gain power and that wouldn't be enough for practical use.

Answer 6

electric powered automobiles are plenty purifier for numerous motives. right this is why coal would not count: * electrical energy isn't made frequently from coal, no count what number situations you will possibly desire to examine this. in basic terms a pair of 0.33 of electrical energy remains created from coal interior the U. S. (see materials under.) the share has been gradually lowering for years. the the remainder of the electrical powered ability comes from organic gasoline, hydro, wind, photograph voltaic, nuclear etc (oil isn't used anymore to make electrical energy, that's too costly.) All of those different materials are plenty, plenty purifier than petroleum. * Coal potential is "baseload". Coal electrical energy flora won't be able to modify immediately adequate to hint changing lots, so as that they are designed to run at one hundred% output all of the time. As electric powered call for adjustments in the process the day, different varieties of flora initiate and supply up - the coal electrical energy maintains to be stable. So plugging in electric powered automobiles would not exchange the quantity of coal pollutants - for the reason which you may no longer run a plant extra durable than one hundred%. * gasoline desires electrical energy, too. extensive quantities of electrical energy, and different fossil gasoline, is used in the process the very potential-in intensity refining technique that turns oil into gasoline. It takes extra potential purely to MAKE gasoline, mile for mile, than electric powered automobiles use. electric powered automobiles purely % electrical energy - gasoline automobiles % the two electrical energy and petroleum.