[weelliott]

One thing you forgot Superchuck. The amount of energy needed isn't just the energy to move the car, but also the enrgy to spin the alternator. It is creating drag on the motor just like the Rolling Resistance and aero forces. Once you add that in, you will see that you are just then going to subtract it out to have no net gain. And once you factor in the inefficiencies involved in getting the electricity from the battery to the motor to the alternator to the battery, then you are actually wasting electricity.

It's like dangling a leg off the side of a canoe into the water. It changes how much work is needed to propel it. taking a figure in a book about how much energy it takes to move a canoe along is no longer valid once you do that.

Bill

[mattW]

You can't have watts per hour because watts is an instantaneous measurement of power. A 50W light globe uses 50W of power all the time, every instantaneous measure of time will show 50W. You can have a W or kW per mph since it takes a certain amount of power to maintain a particular speed, energy is actually power x time measured in Watts x hours or Wh. Do you get the distinction?

Lets try your example again using more accurate numbers, it takes about 18kW from the batteries to maintain constant 60mph in a normal car. If we have a 36kWh pack then we will be able to maintain that speed for two hours (time=energy/power). That will give us an efficiency of 300Wh/mile. Lets say we add an 10 12V alternators that puts out 150A to recharge our 120V battery pack. Those 10 alternators will deliver 18kW of power back to the batteries which should be enough to keep on rolling right?

Well the problem is those alternators are going to draw their power from the motor (either directly or indirectly via the road and wheels). Lets say you have some of the worlds best alternators that are amazingly 95% efficient at recovering energy. That means that in order to produce 18kW for the batteries these alternators are going to draw about 19kW from the motor. That is in addition to the 18kW that is used to power the car. So in total you have 18kW going into the batteries (from the alternators) and 27kW coming out of them. So it now takes 19kW to travel the same speed and the same battery pack will only last 1hr 53 minutes and only get 114 miles instead of 120. That is using statistics that are optimised for this to work (i.e. a near perfect alternator). So you lose 6 miles of range because of the world best alternators that I made up.

In a much more real situation. Typical alternators run at a much lower efficiency of 55% and if you run them off a motor/controller that is only 80% efficient then you can recover 44% of the power it takes to run them. So for the highway example above using more real-world measurements 10 alternators to make up for the 18kW of energy it takes to go down the highway would take 41kW of energy from the batteries meaning the 120 mile range you originally got without the alternators is now 53 miles with them. You threw away 67 miles of range. The efficiency of the system goes from 300Wh/mile to 683Wh per mile. If you use the Department of Energy's method of converting electrical efficiency into mpg you get 273.5mpg without the alternators and 120mpg with them. They do the opposite from what was intended.

AND THAT IS WHY FREE ENERGY DOESN'T WORK!!!!!!!!!!!!!

[Phyber Optik]

Poor guy. He at least deserves an A for effort with his alternator theory.

I have model RC flying wings which are elevon controlled (basically 1 aileron on each wing half). Each are moved by an independent servo, this enables elevator up/down (they move together as one) and moving opposite one another for roll.

Never fails that even some experienced pilots ask me why I didn't try to save weight and use just one servo with a dual arm linked to each elevon....then they think about it for a moment, and go OOoohh, yeah. (This setup would provide roll only)

[SuperChuck_A11]

But I have a 800 watt stereo, I can't recharge the batteries with it ???

[Dan53]

I remember when I was a kid I had that game, Daytona USA, a racing game if you don't know. I was very good at it. Once my sister said she wanted to play. I accepted her challenge, knowing full well that I'd give her a sore whopping. When the race started, I took off in the perfect form that I have trained myself to do, putting on a flawless display. My sister, on the other hand, took off in full acceleration, never easing and never using the brake. She hit the wall on every single turn. And by the end of the race, she had LAPPED me, and broken my record. Not having a clue how to play had enabled her to drive faster than I thought possible. The point is, I agree with what some of you are saying in that it seems that those of you that are really smart just throw up your hands and say "it can't be done" because you know better. But I knew damn well that I would beat my sister in that game, too. People also knew that the world was flat. I think that charging your batteries as you drive must be possible, and if it's not, that there's something that can be done to at least improve the current technology. An alternator attached to each of the four wheels that charges one set of batteries while you power the engine with another, and then flick a switch and the opposite happens, perhaps? Maybe this wouldn't work for whatever reason, but the idea is that it's not free energy, though it's just as good. And it's probably going to take creativity, not intelligence (though admittedly it would probably be a lot of both). Hell, how about some pedals in the car for the passengers to keep busy with powering a generator? hehe

Dan

[Manntis]

Originally Posted by Dan53

I remember when I was a kid I had that game, Daytona USA, a racing game if you don't know. I was very good at it. Once my sister said she wanted to play. I accepted her challenge, knowing full well that I'd give her a sore whopping. When the race started, I took off in the perfect form that I have trained myself to do, putting on a flawless display. My sister, on the other hand, took off in full acceleration, never easing and never using the brake. She hit the wall on every single turn. And by the end of the race, she had LAPPED me, and broken my record. Not having a clue how to play had enabled her to drive faster than I thought possible. The point is, I agree with what some of you are saying in that it seems that those of you that are really smart just throw up your hands and say "it can't be done" because you know better. But I knew damn well that I would beat my sister in that game, too. People also knew that the world was flat.
Dan

The difference being, with a video game if you just wing it and crash there's a reset button. Do the same with a real vehicle and you could have an electrical fire, a runaway, etc.

[sir]

I quite like the idea of over unity devices , I think if you use magnets stong enough to overcome the drag and bigger guage wire for les resistance with more poles to generate electricity at lower rpm and quick charging batteries or maybe capacitors it might just work if you have the coin to fund it . Who knows one day we wont need batteries , thats wishful thinking .

[Phyber Optik]

One day we may be able to manipulate Earth's gravity so that we're always coasting downhill. And levitating like a Land Speeder.

Then again, by the time science advances for that to happen, we'll probably already have teleportation.

Beam me over Scotty.

[Walkeer]

Originally Posted by Dan53

The point is, I agree with what some of you are saying in that it seems that those of you that are really smart just throw up your hands and say "it can't be done" because you know better. But I knew damn well that I would beat my sister in that game, too. People also knew that the world was flat. I think that charging your batteries as you drive must be possible, and if it's not, that there's something that can be done to at least improve the current technology. An alternator attached to each of the four wheels that charges one set of batteries while you power the engine with another, and then flick a switch and the opposite happens, perhaps? Maybe this wouldn't work for whatever reason, but the idea is that it's not free energy, though it's just as good. And it's probably going to take creativity, not intelligence (though admittedly it would probably be a lot of both). Hell, how about some pedals in the car for the passengers to keep busy with powering a generator? hehe

Dan

It makes me wonder how is it possible you dont see it. You want to attach alternator to weels to charge batteries. Ok, why not. I guess you know that if tou want to generate some power by alternator, you have to spin it by some force and the more power you want, the more force tou have to apply. Wind generator generates more power when winds blow faster and thus provide more force. Ok, back to EVs. So the force that you want to apply to alternator to produce energy for battery charge is taken....from weels, so it will slow down vehicle. Energy you get from slowing down the EV by alternator will always be smaller than energy you need to propel the EV unless you use super-conduite motors, invertors and aplternators...than it will be equal..with no energy left to actualy move the car...
Scientics beleive that the conservation of energy priciple is the most significant physical principle we know. And I guess everybody cal feel it is fair that it is this way...it would be odd to produce energy (=mass, E=mc2) from nothing, dont you think?

[SuperChuck_A11]

Originally Posted by Dan53

I think that charging your batteries as you drive must be possible, and if it's not,
Dan

DAn nobody says it is not POSSIBLE. It is very possible, in fact that is what a REGEN Braking System does.

1. Even with a Regen Braking though your not going to recover 100% or 110% of the Electric used to drive the car forward.
so sooner or later, your batteries are depleted.

2. We are also saying that using a Car-type Alternator to recharge while underway will not FULLY CHARGE you batteries either.

ergo no unlimited range.