Wirless car charging

[zhackwyatt]

I'd like to see data on:
- The noise this thing makes, i.e. transformer hum
- The magnetic field strength at a few feet away

Based on anticipated field strength alone, I'm a hard pass.

I'd like to know if it comes with tin-foil underwear for protection.

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[GoGoGadgetMachE]

I'd like to know if it comes with tin-foil underwear for protection.

underwear and hat set.

 

[sockmeister]

I'd like to see data on:
- The noise this thing makes, i.e. transformer hum
- The magnetic field strength at a few feet away

Based on anticipated field strength alone, I'm a hard pass.

This made me want to go look up research!

A study was recently performed on just this, at an engineering university in Italy. You can read the full paper online.

As little as 40cm to the left and right of the CENTER of the coils, the magnetic flux density drops to levels well below the ICNIRP guidelines for non-ionizing radiation exposure. They even took into account

1) being inside the car while charging,
2) parking misalignment with the coils,
3) varying car size, shape, and height

And found that exposure levels are below the ICNIRP levels.
However, they did note that on very narrow car configurations, when standing directly to the side of the coil when the vehicle was offset, or if it is too tall (beyond 250mm), some amount of EMF energy above the ICNIRP limits are present if you were to stand right up against the front sides of the car.

But .... EMF is non-ionizing radiation. There's zero evidence that it affects us in any way, other than to make you slightly warm, and that's after almost 3 decades of scientific study. The guidelines were established to calm people who are worried about it anyway.

Non-ionizing radiation is the same as light from a lamp or wifi radio waves. It doesn't have the energy to displace electrons and damage tissue or cause cancer.

So in short, there's nothing to worry about here.

Link to the article: https://www.mdpi.com/1996-1073/12/9...FjABegQIAhAB&usg=AOvVaw3MjOkA1s7wtssWjYZFSDgs

 

[RonTCat]

This made me want to go look up research!

A study was recently performed on just this, at an engineering university in Italy. You can read the full paper online.

As little as 40cm to the left and right of the CENTER of the coils, the magnetic flux density drops to levels well below the ICNIRP guidelines for non-ionizing radiation exposure. They even took into account

1) being inside the car while charging,
2) parking misalignment with the coils,
3) varying car size, shape, and height

And found that exposure levels are below the ICNIRP levels.
However, they did note that on very narrow car configurations, when standing directly to the side of the coil when the vehicle was offset, or if it is too tall (beyond 250mm), some amount of EMF energy above the ICNIRP limits are present if you were to stand right up against the front sides of the car.

But .... EMF is non-ionizing radiation. There's zero evidence that it affects us in any way, other than to make you slightly warm, and that's after almost 3 decades of scientific study. The guidelines were established to calm people who are worried about it anyway.

Non-ionizing radiation is the same as light from a lamp or wifi radio waves. It doesn't have the energy to displace electrons and damage tissue or cause cancer.

So in short, there's nothing to worry about here.

Link to the article: https://www.mdpi.com/1996-1073/12/9...FjABegQIAhAB&usg=AOvVaw3MjOkA1s7wtssWjYZFSDgs

I agree under ideal charging conditions, field strength can be kept to safe levels. My concern would be:
- The maturity of all the safety systems... like the ones that assure your microwave oven doesn't continue to operate if you open the door while it is in use.
- The effects on other electronics... my GPS/phone, etc. doesn't work in proximity to a charger.
- The effects on wildlife... migrating birds are disrupted because they can no longer sense the earth's magnetic field near chargers.

We have high energy transformers now, but we would increase that total by a 1000 times. I see the reward as very small, and the risk as high.

 

[sockmeister]

I agree under ideal charging conditions, field strength can be kept to safe levels. My concern would be:
- The maturity of all the safety systems... like the ones that assure your microwave oven doesn't continue to operate if you open the door while it is in use.
- The effects on other electronics... my GPS/phone, etc. doesn't work in proximity to a charger.
- The effects on wildlife... migrating birds are disrupted because they can no longer sense the earth's magnetic field near chargers.

We have high energy transformers now, but we would increase that total by a 1000 times. I see the reward as very small, and the risk as high.

I respect your healthy skepticism. But I don't see any reason to be concerned in this case.
I'm not sure what risk there is. It's a small magnetic field and radio waves.

Even under non-ideal conditions, a magnetic field like the one generated by charging coils like this won't affect anything. It's got a very short (less than 50 cm) range, and... also, what's it going to affect? You're probably better off wondering if MRI machines, which have a magnetic field orders of magnitude higher, are affecting any life anywhere.

EMF radiation in the form of radio waves will be produced, but that'll be as harmless as your wifi radio waves. And it'll be at a different frequency.

As for your phone and other electronics' functions, I imagine if they were placed next to or on the coils while it was charging, they would have compass issues. Signal won't be a problem; the chargers operate at a different frequency than wifi / cell radio waves. I don't think this would be a good idea though; rogue induced currents in the phone's circuits could cause software glitches.

Migrating birds would have to be underneath your car or sitting next to the front wheels while charging to be affected. Once they took off, they'd no longer be confused. But I am not basing this off of any research; that's an assumption based on the physics of it.

 

[JamieGeek]

I respect your healthy skepticism. But I don't see any reason to be concerned in this case.
I'm not sure what risk there is. It's a small magnetic field and radio waves.

Even under non-ideal conditions, a magnetic field like the one generated by charging coils like this won't affect anything. It's got a very short (less than 50 cm) range, and... also, what's it going to affect? You're probably better off wondering if MRI machines, which have a magnetic field orders of magnitude higher, are affecting any life anywhere.

EMF radiation in the form of radio waves will be produced, but that'll be as harmless as your wifi radio waves. And it'll be at a different frequency.

As for your phone and other electronics' functions, I imagine if they were placed next to or on the coils while it was charging, they would have compass issues. Signal won't be a problem; the chargers operate at a different frequency than wifi / cell radio waves. I don't think this would be a good idea though; rogue induced currents in the phone's circuits could cause software glitches.

Migrating birds would have to be underneath your car or sitting next to the front wheels while charging to be affected. Once they took off, they'd no longer be confused. But I am not basing this off of any research; that's an assumption based on the physics of it.

Not mentioned is that there would be a proximity sensor so that if the car wasn't present the charging coils will be off and thus no field.

 

[mkhuffman]

Sure it's "convenient" not to have to plug in, but there clearly will be a significant loss of efficiency. I'd rather have to take the 15 seconds to plug and unplug than pay for say 30% extra electricity for the "convenience" of saving those 15-30 seconds. I already envision using 500 kwh a month, I'd rather not draw another 150kwh because I'm lazy.

Not everyone would find the convenience of a wireless charger to be worth the cost, and your use case sounds like one that might not be worth it. However, in our COVID world, my car is parked in my garage 99% of the week. I am sure that will change, but while it sits there, it can charge. Surely wireless charging will be much slower than plugged charging, but since it sits there for so long, it won't matter. Once I am back back to driving long commutes (by the summer hopefully), having wireless at home would not be a big benefit for me. Where I would see a benefit is when businesses install them in parking spaces so that everywhere I park, I get a few miles of charge per hour. It will reduce my need to plug in, but probably not eliminate it.

My wife, on the other hand, would LOVE this. Her use case is very unlikely to change post COVID. She rarely drives more than 20 miles at a time. Her car may sit in the garage for a day or two before she drives again. And she will find it annoying to have to remember to plug in when the battery gets low. For her, it will change her driving life to have a wireless charger. In fact, I think for a huge percentage of the public, wireless charging will be the factor that gets them to buy an EV. My wife will never need to plug in, ever, especially if she gets charges while parked at a business. How awesome is that?

 

[dbsb3233]

Charging efficiency is up to 94%, comparable to wired connections.

Only 6% loss vs charging with a cable?!? That sounds awfully optimistic.

 

[ChasingCoral]

underwear and hat set.

But wait, you can also use it to erase your hard drives!

 

[ChasingCoral]

That’s like saying you can’t havepublic L3 chargers if all cars accept L2 and only some accept L3. The good part is standards are being set so that it will encourage wider adoption to avoid the Tesla/CCS/CHAdeMO incompatibility issued.

 

[engnrng]

In the real world, most of the installs of wireless charging have been for fleets, not individuals. Your conclusion or supposition "it's exclusively for home charging" is your opinion, not a statement of fact. And, it is not called an "adapter" since there is nothing physical to adapt. The part mounted on the bottom of the vehicle is called a "receiver".

 

[JamieGeek]

There is a standard, that's the whole point of the article: There is now a SAE standard for wireless EV charging.

Now OEMs can build that in.

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