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Charging batteries in electric cars

I have read many discussions that the electric car will never be financially viable. What if someone devices the means of charging the battery while driving. How many kwh’s would it take to continually charge the battery that will provide the energy to drive a 55kwh motor ? >OR< at least double the 100 mile range of the Nissan Leaf ?

This would be the same as a ‘perpetual motion machine’. You can’t charge the batteries while using the same batteries to run the car, you lose energy at every step. Electric cars (and hybrids) already do some battery charging while braking, but it’s always less than the amount of electricity needed to get moving. Has to be.

The electric vehicle will be viable when the weight of the battery goes down and the battery life goes up. Super conductive electric motors will also help the process along. I don’t see it happening for the foreseeable future. Coming up with a way to match the battery consumption and battery charging is wanting your cake and eating it too. Nuclear fission would work but that opens up a whole new can of very dangerous worms.

They are viable…but only for a very small select group of drivers. You need a certain number of driving miles and the right commute in order for it to be viable. But if you have that commute and drive a certain miles per year…then they are very viable.

Never say “never”. Electric venicles may very well be economically viable with one or two technology breakthroughs. Nobldy prior to the 20th century ever thought that cars would displace horses as the primary means of transportation.

The only way car would be able to charge at the same time they were driving would be if someone were to come up with a super-duper efficient solar cell, and to cover the roof, hood, and trunk. Hey, it could happen. Any mechanical system to generate a charge would only contribute a net loss. No system can ever create more energy than it uses. There’s always a loss.

The only thing I can picture here is an induction charging system like the ones that have come out for cell phones recently. That would have to be tremendously expensive to set up. There could also be health issues and even issues for magnetic storage equipment like computer hard drives.

Thanks for all the comments. Now please humor me. What if i mounted a windmill on top of my car, how many kwh would I have to produce to charge the battery anough to double it’s milage range ?

All series hybrids do essentially that, charge while driving. It’s just a mater of coming up with a charger that does it fast and efficiently enough to make it worthwhile. That’s what the Volt does now, inefficiently. The Leaf actually has a small solar panel that trickle charges somewhat all the time. Now, if some day, solar chargers become efficient enough so that in the sun belt it would make a significant increase in range and decrease charging time, you’d have something.

Maybe a small reactor that could power a steam turbine and charge it for one fueling for the life of a car…a windmill ? I would be inclined to think the added wind resistance would use up what ever energy you tried to generate…

Yep, anything that is powered by the electric motors moving the car (a generator powered by the wheels or by a windmill) is an instant loser, energy is lost in all the conversions. Only through an additional energy source (an IC engine in a hybrid, or an amazingly efficient solar panel) can the charge be maintained.

konne wrote:
What if i mounted a windmill on top of my car, how many kwh would I have to produce to charge the battery anough to double it’s milage range ?

If you add a windmill, you’ll reduce the range, not increase it.

It will require more energy to overcome the drag and friction of the windmill than the windmill produces…

GM solved the problem with the Chevy Volt…

There are a few 100% electrics with unlimited (daytime) range, special vehicles covered with solar panels that can go 30-40 MPH as long as the sun shines on them. They are not practical cars…

I’ve always wondered this. If battery storage is the big hold-up re: electric cars, and people like them particularly for zero tailpipe emissions in urban areas…

…why not just put the trollycar electric system back up? Proven technology, saves weight, cost, etc.

Figuring out how to charge for the electricity would be a problem, but hardly insurmountable. You could have a small battery or auxiliary engine for rural sojourns.

P.S. to the OP: the reason the windmill won’t work is that the aerodynamic drag of the windmill–by law of physics–would exceed the electrical energy produced.

A windmill on the roof would produce a lot of aerodynamic drag. With energy losses due to inefficency you would end up losing overall. Your car’s battery would run down faster from the drag than the energy produced by the windmill could replace.

Now a car with very efficient solar panels on the roof, hood, and trunk lid could produce a lot of power. That would extend the range of the electric car and can recharge the batteries when parked. This technology is available now, but the panels need to be lighter, more robust, more efficient, and better looking before they make it into a production car.

And cheaper, Uncle T.

Konnie, a windmill takes energy to make it turn and to generate electricity. The energy you’d be using by mounting it on the vehicle would be coming from the gasoline. You’d lose.

Hybrids recover some of the energy, but they do not charge anything. The energy they recover, be it from inertial energy or energy from a motor/generator arrangement, originates in the gas. Normally, the inertial energy is 100% comverted into heat energy by the brakes (and some by the tires too). In a regenerative braking system, some of it is converted to electrical energy. But it can never generate more energy than was created originally by the gasoline.

The same would happen with a generator. It would take more energy to operate it than it would return. You can never get more energy out of any system than you put into it. That’s the basics. And in any system there’ll always be losses.

Hybrids are good,helping to recover some the energy that would be wasted as heat and helping the petrol engine to operate close to peak efficiency,but while solar cells could help somewhat,strong sunlight on the earths surface can only generate around a HP per sq meter-still a lot of power over time,you have to accumulate it-Kevin

@kmccune - exactly. Folks need to realize it’ll take square MILES of solar cells to generate substantial power compared to what we use. The solar cells on the sunroofs of hybrids are to run circulating fans, that kind of thing. They don’t charge the batteries, typically.

The only way car would be able to charge at the same time they were driving would be if someone were to come up with a super-duper efficient solar cell,

Wellll, not quite. There’s already research being done on inductive coils embedded in the roadway, which would charge the car as it drove over. So far, it wouldn’t be enough to completely charge it, but it would extend the range quite significantly.

You could always mount a 8500 watt construction generator on the trunk lid, or just remove the trunk lid and place the generator inside that space…Then just plug the car into that…

I never meant to imply that covering the car with solar cells would be able to keep the battery fully charged in an EV, only that it was the only way I knew that a system could generate power while the car was running without it originating in the gasoline. It’s the only way to get energy not from the gasoline on a non-plugin car, albiet a small amount of energy relative to what a car needs.

Shadow, you’re right. I’ve read about this technology. Time will tell. Frankly, I’d be happy of they’d just fix the potholes!

I’m holding out on buying an electric until they come out with the “Mr. Fusion home energy reactor” (think Back to the Future movies…)