Automakers Want To Cut The Cord On Electric Cars Plugging in an electric car — or parking it on a charging mat — may soon be a thing of the past. Robert Siegel talks to Rachel Kaufman of Scientific American about the new developments to boost car batteries on the go.
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Automakers Want To Cut The Cord On Electric Cars

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Automakers Want To Cut The Cord On Electric Cars

Automakers Want To Cut The Cord On Electric Cars

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From NPR News, this is ALL THINGS CONSIDERED. I'm Robert Siegel. And it's time now for All Tech Considered.


SIEGEL: Automakers are thinking about cutting the cord for electric cars. Developments are underway that could let drivers recharge their car batteries without ever plugging in or parking on a charging mat. Instead, you could recharge wirelessly with the help of magnetic fields.

Rachel Kaufman wrote about this in Scientific American, and she joins us now in the studio. Welcome to the program.


SIEGEL: Electric cars that you plug in have only recently entered the U.S. auto market, so why the move already toward wireless charging?

KAUFMAN: It's just more convenient. People forget to plug in their phones, people might forget to plug in their cars. If you've got a car that only runs on electricity, then if you forget to plug it in, you can't go to work the next day. If you've got one that also runs on gas, you're not getting any of the benefits, if you only use the gas motor.

SIEGEL: Well, you've outlined two kinds of wireless charging in your article. First, a stationary. Explain to us how that would work.

KAUFMAN: Well, just like the charging mats that you mentioned, where you would drive up to this mat and park, this is Charging Mat 2.0. Instead of using an indiscriminate field that sends energy in every directions, these guys at MIT have invented a magnetic coil that only transmits energy at a very specific frequency.

So if you imagine an opera singer who is able to sing a high note and shatter the proverbial wineglass, this way you can transfer energy to your car's charging device at higher frequencies without affecting anything else in your garage.

SIEGEL: And if you walk near this space with the, you know, the current normal array of electronic devices, they wouldn't be thrown off by being in this?

KAUFMAN: Nothing would be thrown off because they're not tuned to this specific frequency.

SIEGEL: Your keys wouldn't get magnetized or anything like that?


SIEGEL: No. It works.

KAUFMAN: It does work. It's developed. It's not in any car that you can buy yet, but it is developed and it works.

SIEGEL: The second method that you write about is dynamic wireless charging. How would that work?

KAUFMAN: Well, in theory, you'd have this receiver at the bottom of your car somewhere. And as you drive along the road, these chargers in the road that are embedded in the freeway will be shooting energy into your car, as you go along. There's obviously a number of issues that need to be worked out with this.

SIEGEL: Including getting them under the freeway.

KAUFMAN: Including getting them under the freeway.


KAUFMAN: Very expensive. And the current batteries that we have, they won't charge fast enough for you to be able to get any benefit from them by driving over them. But in theory, in the future, it is possible.

SIEGEL: How long does it take to actually fully charge a battery for, say, a Chevy Volt or a Nissan Leaf?

KAUFMAN: I believe it takes about eight hours. You plug it in overnight. When you're ready to go to work the next morning, you just pick it up and go. And if your employer has a charging station there, then you can plug it in while you're at work.

SIEGEL: Going back to the stationary method you described, sort of like the recharging mat - the charging mat that isn't actually a mat. It's a field there. Is that something that's anywhere near the market right now? Is it over the horizon? Or...

KAUFMAN: Well, the company that makes it, they have put it into a prototype car and they're driving it around Detroit right now. They've signed a number of deals with auto-making companies. Delphi Electronics, which makes a lot of auto parts, is working on putting this into cars. I'd say we can definitely see this within the next 10 years.

SIEGEL: I'm talking to Rachel Kaufman who wrote about wireless charging of electric cars in Scientific American. Rachel, thank you very much for talking with us.

KAUFMAN: Thank you very much.

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