Can EVs be wirelessly charged?

[AZjeff]

I'm electronically challenged and can't comprehend how electricity is transmitted through air but am guessing it's a technical problem with so many batteries? Would there be a danger as well like if the cat crawled under the car while it's charging?

 

[wings&wheels]

Being done:

Porsche Wireless Charging

I'm no EE, but I'd guess that the pads will have sensors for a lot of possible scenarios. If it is TUV certified, I'd say its probably safe.

 

[AZjeff]

Thanks. That article is almost a year old, has it gone public yet?

 

[SC Maintenance]

Its called an inductive coupling, and yes its possible. Its also not very efficient so I doubt you see them large scale.

A simple transformer is usually 2 coils inducing power into a iron or similar core.

An inductive coupling is a coil on one side with usually AC power, whose field induces power into a coil on the other side. So the iron core has been deleted. However it takes a lot more energy on the inducing side than you get out on the powered side.

It works on a cell phone because the gap is very small and the power requirements pretty small as well. I don't see it being use broadly for EV charging due to efficiency and cost. But who knows.

 

[Rand]

My 2 cents.
It has some challenges as mentioned..
mainly distance(gap) and inefficiency.

The phone wireless charger is a good analogy.. of course with that the gap is a small fraction of an inch.. and even a thick case will stop it from working.

I could see it maybe working for parking in a garage and the charger lifting from the ground to a specific spot on the chassis... AI camera used for positioning all that tech is here.

One that works driving on the highway is a ways off.

They would need very high efficiency or you are going to have a space heater from the waste heat.. and lost electricity $$

 

[mk378]

It uses AC magnetism at tens to hundreds of kiloHertz. An inductive stove works the same way except at the output side no attempt is made to recover the energy as electricity, as the desired effect is to heat the pan.

The Porsche system lowers the car after it is parked so it is almost touching the charger. A similar thing has been done with buses where the receiver on the bus lowers to the road at bus stops.

 

[y_p_w]

There have been pilot projects.

https://www.michigan.gov/mdot/travel/mobility/initiatives/wireless-charging-roadway

 

[demarpaint]

Any health hazards?

 

[AZjeff]

Aren't EV battery packs hundreds or thousands of small batteries? Would they all get the same state of charge?

 

[alarmguy]

I don't see it ever becoming mainstream, wildly inefficient. It will be a non starter except for possibly boutique products.

 

[alarmguy]

Any health hazards?

That does not matter! If they can sell it, that can will be pushed down the road a few decades! There is still debate on induction cooking and power lines in general. Dont let a massive amount of energy around your vehicle humming through your body bother you!

I do think (too much) but the biggest health hazard in the human race is the food we choose to eat. At least three full isles in supermarkets are filled with 100% poison.

 

[demarpaint]

That does not matter! If they can sell it, that can will be pushed down the road a few decades! There is still debate on induction cooking and power lines in general. Dont let a massive amount of energy around your vehicle humming through your body bother you!

I do think (too much) but the biggest health hazard in the human race is the food we choose to eat. At least three full isles in supermarkets are filled with poison.

I agree, and I know that type of charging is a hazard, I was testing the waters here. I wouldn't live near a train track, high intensity power lines, or a substation, to name a few. I'd want no part of that type of charging either.

 

[alarmguy]

I agree, and I know that type of charging is a hazard, I was testing the waters here. I wouldn't live near a train track, high intensity power lines, or a substation, to name a few. I'd want no part of that type of charging either.

No substations for me nor large power lines towers. We used to watch for them in communities where we used to live. We always love looking at homes and many communities are almost split in half because of the giant high tension towers *LOL*
By all means not all. But we used to live near Lake Murray SC ... with the Nuclear Plant about 15 straight line miles from us, not road miles. Anyway ... the lines would run, not by us, but across to the eastern part of the state and many new community were built around them.

Then they started 2 new nuclear plants next to the existing one, turned into a disaster and construction stopped (most likely will be restarted someday> However that actually already installed the new towers, next to the old towers to carry the current from the plants not completed and they run right along the right of way of the older lines, right across the state. SO one day these communities will have the current of not one plant but three.

 

[demarpaint]

No substations for me nor large power lines towers. We used to watch for them in communities where we used to live. We always love looking at homes and many communities are almost split in half because of the giant high tension towers *LOL*
By all means not all. But we used to live near Lake Murray SC ... with the Nuclear Plant about 15 straight line miles from us, not road miles. Anyway ... the lines would run, not by us, but across to the eastern part of the state and many new community were built around them.

Then they started 2 new nuclear plants next to the existing one, turned into a disaster and construction stopped (most likely will be restarted someday> However that actually already installed the new towers, next to the old towers to carry the current from the plants not completed and they run right along the right of way of the older lines, right across the state. SO one day these communities will have the current of not one plant but three.

Agreed. Shoreham is about 40 miles from us. I can't imagine a nuke plant being any less than 20 miles from here, which will be many years from now if it happens. No high intensity power lines, and the Malverne train station is about 1/2 mile away. We're pretty save as far as electric goes for now.

 

[Volvo_Expert_Tech]

As a former BEV leaser, BEV technician that tore apart the 400v batteries, and now studying electrical engineering; wireless charging for a car would be extremely slow compared to the already super slow 110v/level 1 charger with current technology. Not to mention the amount of current flowing in the air would be frightening. People are already burning down their houses out of stupidity by using extension cords, I cant imagine wireless charging. The fastest possible charging is DC/DC but Volvo says you should only do it once a month as it shocks the battery too hard. EV technology is just not there yet and I will never lease or own another.

 

[SC Maintenance]

As a former BEV leaser, BEV technician that tore apart the 400v batteries, and now studying electrical engineering; wireless charging for a car would be extremely slow compared to the already super slow 110v/level 1 charger with current technology. Not to mention the amount of current flowing in the air would be frightening. People are already burning down their houses out of stupidity by using extension cords, I cant imagine wireless charging. The fastest possible charging is DC/DC but Volvo says you should only do it once a month as it shocks the battery too hard. EV technology is just not there yet and I will never lease or own another.

There is no electricity going through the air. Its simply an inductive wave - like an inductive cooktop, or inductive prox switch - only stronger. Inductive is a type of magnetic wave, and it induces the charge in the far side coil. There is no danger.

It could be an issue for someone with a pacemaker, etc - I don't know. Just from the energy wave. You would need to ask the designers of the pacemaker? Still, inductive fields dissipate pretty quickly with range - like a magnet. I have seen inductive couplings in industrial, they carry a fair bit of power and they still only have a range of a few mm.

 

[Volvo_Expert_Tech]

There is no electricity going through the air. Its simply an inductive wave - like an inductive cooktop, or inductive prox switch - only stronger. Inductive is a type of magnetic wave, and it induces the charge in the far side coil. There is no danger.

It could be an issue for someone with a pacemaker, etc - I don't know. Just from the energy wave. You would need to ask the designers of the pacemaker?

I have not researched wireless charging a vehicle but I am thinking that in phones it is slower than wired charging and produces more waste heat and affect battery longevity.

I deal with some powerful EMF radars in my line of work and we have to ensure nobody is within 100ft during initial start up bursts, I wonder if the vehicle wireless charging would be the same burst.

 

[SC Maintenance]

I have not researched wireless charging a vehicle but I am thinking that in phones it is slower than wired charging and produces more waste heat and affect battery longevity.

I deal with some powerful EMF radars in my line of work and we have to ensure nobody is within 100ft during initial start up bursts, I wonder if the vehicle wireless charging would be the same burst.

It will definitely waste a lot of energy vs a connector.

I am not that familiar with EMF / radar - but I can receive radio signals on my cheapy shortwave radio from around the world if the ionosphere is working

The largest inductive coupling I have seen in a factory was 10A, and it had about 1/4 inch of range. Its similar in tech to a RFID tag, but the passive tag only has to produce an absolutely tiny amount of power.

But the wave exists - so in theory it can interfere with communications and possibly things like pacemakers, etc? I am not a physicist so don't know.

 

[rijndael]

Christian Holler, Porsche’s head of charging systems, says the system conforms to International Commission on Non-Ionizing Radiation Protection standards for electromagnetic radiation. The field remains below 15 microteslas, so it’s safe for people with pacemakers, Porsche insists. And the aforementioned cat wouldn’t be harmed even if it strayed into the magnetic field, though “its metal collar might get warm,” Schulze says.

Last year, Oak Ridge National Laboratory transferred an impressive 270 kilowatts to a Porsche Taycan with 95 percent efficiency.

In most EVs, plug-in (conductive) AC charging tops out at around 95 percent efficiency. Porsche says its wireless system delivers 90 percent efficiency, despite an air gap of roughly 12 to 18 cm between the pad and vehicle.

https://spectrum.ieee.org/porsche-wireless-ev-charging

 

[SubieRubyRoo]

If Battery EVs were ever to become really useful, it’s going to be once we’ve mastered the art of mega-capacitance. That is, not only huge storage potentials in no bigger than an EV-battery size package.

Why do I think this? Capacitors can discharge more current than any reasonably-sized battery, making the Plaid S Ludicrous mode seem tame for current and torque. They can charge extremely quickly also (think parking over a Qi charging pad) and as long as they’re made properly, either fully charging nor fully discharging affects anything as far as capacity or lifespan. Capacitor charge/discharge cycle ability dwarfs even the very best battery technology around.

Biggest problem I see: if there’s a short-circuit, there’s no Class D fire to contend with. There was likely an insanely bright bluish flash, a thunderclap from the spark gap ionization, and a pile of cinders to sweep up from where the vehicle used to be.