“and claims a charging rate of up to 11 kW and with an efficiency of about 90% for easy overnight charging.”
That’s a some 9kW lost on a 80kW battery. I get the convenience, but I think the best use for those would be when standardized and installed in public parking spots, for a brief charge bump, not to charge fully at home, e.g overnight, which is what Porsche aims for.
The 90% efficiency of the wireless transmission would be on top of the efficiency of typical charging (which is mostly losses after the power reaches the vehicle).
Do we? Because if you're invoking scare quotes, I don't think you have a good grasp on what's actually happening here.
90% is pretty good efficiency at this level of power. One cannot give an exact figure because it depends heavily on environmental factors, primarily temperature. 90% is pretty much exactly what I'd expect to see in the real world under same conditions.
Porsche is famous for underpromising and overdelivering.
For instance they claim a 0-60 time of 2.4s for this car. Car & Driver independently tested it and achieved 2.1s. They also claim 298 miles of EPA range (mixed highway & city driving). Car & Driver worked out 300 miles at a constant 75 mph (which is harder on an EV than city driving.) On the base model, which claims 303 miles range, MotorTrend achieved 350 miles of pure highway driving.
Pick any Porsche and you'll see that they lie to make things sound worse than they really are.
Charging rate of 11 kW, with efficiency of about 90%, means that the charger sucks around 12.2 kW of power from the grid, of which 1.2 kW is continually lost*, and only 11 kW is effectively being stored in the battery at any point in time.
I don't understand the mention about battery capacity (80 kWh, which would translate to around 7½ hours of charging at 11 kW, if a battery could charge at a uniform rate) or where the "9 kW lost" figure comes from.
*Which is probably useful to melt snow above the device, when installed outdoors on cold climates.
Charging at home is already more convenient and quicker (in human time) than driving to a gas station, and now they're optimizing the 30 seconds it takes to plug the car in.
We’re talking about a particularly inconvenient 30 seconds coming out of an expensive machine built entirely for convenience. Some people will want it and pay for it. If I was in the market, I probably would.
I agree in so far that plug-in charging shouldn't be an issue for most people.
Yet I can see the advantages for someone with a disability.
And what a lot don't seem to understand: at 11kW we aren't talking about high charging efficiency anyway.
Meaning, you cannot assume close to 100% for cable based charging and talk about how much 90% loose on a full battery (like others here do).
Home charging us a reasonably thick cable. It’s not bad by any stretch but it’s more than an appliance cord.
Plus you just got home. You probably want to go inside and may be carrying packages or such, which you might have to juggle or put down to get the cable and plug in.
When it’s time to leave you have to unplug and then store the cable, leave it on the floor (trip hazard for others), or have installed an overhead cable system.
With wireless it’s all gone. Pull into you’re garage? You’re done. You were doing that anyway, so it’s no different. Ready to leave? Just back out. Again, same thing. Nothing extra.
Yeah it’s convenience. But it’s not a small win, it’s big. And it’s every time you use your car. Twice.
Your car can always charge. It can always precondition. You used to have to go to gas stations, now you don’t even have to plug in. It’s fully automatic and taken care of for you.
“You don’t need a remote. You can just get up to change the volume”. How well did that argument go over? Every TV has remotes. Buttons are hidden and effectively dead.
It's not just that; there's a new capability unlocked. You can now have self driving cars charge at remote places and come back without human interaction. Imagine you live in a place with no grid power
I have a robot vacuum that manages to do automated direct contact charging just fine. I don’t understand why wireless would be any easier. It seems more complex and less safe than a direct wired connection.
I also have a lot of trouble believing in the scenario of a neighborhood that has an automated charging station for EVs but no grid. That seems like very misplaced priorities.
Robo vacuum charging is almost inherently safe. They probably charge at something like 12V/2A. Voltage too low to penetrate skin, wattage too low to cause serious injury unless you’re really trying.
You can kind of just leave them exposed and live.
None of that applies to a 220V, 50A (or whatever amperage) charging. That can absolutely kill somebody; jet fuel may not melt steel beams, but 11,000W sure will.
You’d end up needing some kind of recess probably, and then getting cars to connect to it like planes refueling mid-flight is a nightmare. You could try some sort of USB-C like signaling before power is sent, but people are never going to enjoy “exposed 220V contacts that may or may not be live depending on if things malfunctioned”.
The point wasn’t that my robot vacuum is handling large current but that “moving device connects to power” is a solved problem. A car capable of driving itself onto this pad could as easily drive itself to a spot to plug in. Extendo-arm from the car could easily slot into an outlet in the floor. Or vice versa. Or a wall or pole.
Planes refueling mid flight is hardly an apt metaphor given the charging station isn’t moving at all and the car can move as slowly as needed.
This seems like one of those “reality has a surprising amount of detail” situations.
Surely getting something to autonomously without fail extend an arm and plug in for the lifespan of these vehicles vs just park in this allocated spot you would park in anyway is an obvious tradeoff.
It’s definitely a trade off but both options have a lot of real world concerns. If safeguards on the wireless pad fail you could easily cook an animal or start a fire. The bottom of the car now needs to be metal free to allow this to work. Distance matters which means if it charges your Porsche it might not be able to charge a Rivian and certainly not with the same efficiency.
I also frankly do not believe the 90% efficiency claim because it seems so much higher than any other wireless charging I’ve heard of.
This seems like one of those things that seems cool but is not generally practical. As a convenience for wealthy Porsche EV owners, sure. As a general purpose charging solution? I doubt it.
> A car capable of driving itself onto this pad could as easily drive itself to a spot to plug in. Extendo-arm from the car could easily slot into an outlet in the floor.
Those two things really aren't comparably difficult. Eg in the dumbest case for pads, you could make the pads slightly smaller than axle diameter (to prevent dead shorts) and have the car randomly jostle around the space until it detects current flow. I've seen some amateur systems that work vaguely like this. Some signal that charging is nearby, and then a semi-random search to find exposed contacts.
That's not going to cut it on a recessed outlet. Your odds of hitting it randomly are tiny, and it will probably the damage the port with enough repetitions of ramming it into the floor.
> Planes refueling mid flight is hardly an apt metaphor given the charging station isn’t moving at all and the car can move as slowly as needed.
Change your reference point to the plane carrying the fuel and they get an awful lot closer. The planes are moving a lot relative to the ground, they're moving very little relative to each other. I'm not sure if you've watched them doing it, but relative to each other it's actually a very slow process.
> Your odds of hitting it randomly are tiny, and it will probably the damage the port with enough repetitions of ramming it into the floor.
Why would it be random? The scenario here is self driving cars. Suddenly we are talking about random jostling instead of actually targeting.
> Change your reference point to the plane carrying the fuel and they get an awful lot closer. The planes are moving a lot relative to the ground, they're moving very little relative to each other. I'm not sure if you've watched them doing it, but relative to each other it's actually a very slow process.
What is your point here? I’m totally lost. You seem to be trying to hand-wave away the difficulty of refueling mid flight. The specific difficulty there is the fact that it’s happening at high velocity, not the difficulty of plugging a hose into a port. (Traditional mid air refueling is manually directed anyway.)
You are probably fully capable of fueling your car at a self serve gas station. Try doing the same at highway speed. Just reach out the window of the vehicle you are in and fill up your friend’s car from a gas can. Should be easy since the cars are “moving very little relative to each other”, right?
I guess if you see the video on the linked post, you'll see what the usecase is unlocked. A neighboor city with a wireless charger station or a road wireless charger station can receive a self driving car above it, charge the car and with some kind of NFC do the payment and goes back.
The 3D rendered video of a car driving over the pad doesn’t really show anything unlocked. There are a lot of possible ways to build automated charging stations. This is not necessary tech for that scenario.
And the funny thing is China's already picked up the dropped torches elsewhere; Xiaomi's going to be launching a robotic arm for your garage by the end of this year to plug in for you. Tesla gave up on their charging tentacle, but, wellp.
I don’t know. I’ve stopped using my wireless phone charger because it’s spotty. Sometimes it charges. Sometimes it doesn’t (or barely charges). Sometimes it wakes me up at night because it’s glitching in between charging and noncharging states and my phone feels the need to beep and wake me up.
I’ve seen similar issues with multiple watch chargers. “Oh, it didn’t charge overnight again.”
I’m not as sold on wireless charging as I once was.
the imaculate lifestyle aproaches, but then in the way of reality, will then prove to be just out of reach, with some new more minor and tedious 'inconvienience' taking on the roll of 'proof' in bieng a victim.
“and claims a charging rate of up to 11 kW and with an efficiency of about 90% for easy overnight charging.”
That’s a some 9kW lost on a 80kW battery. I get the convenience, but I think the best use for those would be when standardized and installed in public parking spots, for a brief charge bump, not to charge fully at home, e.g overnight, which is what Porsche aims for.
> That’s a some 9kW lost on a 80kW battery
It's about the same as wired AC charging. There are always charging losses:
https://insideevs.com/features/711659/ev-charger-efficiency-...
The 90% efficiency of the wireless transmission would be on top of the efficiency of typical charging (which is mostly losses after the power reaches the vehicle).
It's 90% from grid to battery.
It is not.
It is "up to 90%"
We all know what this means in reality.
Do we? Because if you're invoking scare quotes, I don't think you have a good grasp on what's actually happening here.
90% is pretty good efficiency at this level of power. One cannot give an exact figure because it depends heavily on environmental factors, primarily temperature. 90% is pretty much exactly what I'd expect to see in the real world under same conditions.
Porsche is famous for underpromising and overdelivering.
For instance they claim a 0-60 time of 2.4s for this car. Car & Driver independently tested it and achieved 2.1s. They also claim 298 miles of EPA range (mixed highway & city driving). Car & Driver worked out 300 miles at a constant 75 mph (which is harder on an EV than city driving.) On the base model, which claims 303 miles range, MotorTrend achieved 350 miles of pure highway driving.
Pick any Porsche and you'll see that they lie to make things sound worse than they really are.
> That’s a some 9kW lost on a 80kW battery.
*kWh
Using the right units is important.
"This may sound like one of those overly pedantic fixations... but it's not. Power and energy are very different concepts." -Technology Connections
https://www.youtube.com/watch?v=OOK5xkFijPc
Charging rate of 11 kW, with efficiency of about 90%, means that the charger sucks around 12.2 kW of power from the grid, of which 1.2 kW is continually lost*, and only 11 kW is effectively being stored in the battery at any point in time.
I don't understand the mention about battery capacity (80 kWh, which would translate to around 7½ hours of charging at 11 kW, if a battery could charge at a uniform rate) or where the "9 kW lost" figure comes from.
*Which is probably useful to melt snow above the device, when installed outdoors on cold climates.
It will still be 90% efficient regardless of who uses it. In fact if it is used more, the total losses will be higher.
(Some of this becomes clearer when you have a feeling for the units: kW is a measurement of power, not energy)
> not to charge fully at home, e.g overnight, which is what Porsche aims for.
Wouldn't an overnight (usually cheaper) 10+ hour charge be a great use for (slow) 11 kW charging?
[dead]
Charging at home is already more convenient and quicker (in human time) than driving to a gas station, and now they're optimizing the 30 seconds it takes to plug the car in.
We’re talking about a particularly inconvenient 30 seconds coming out of an expensive machine built entirely for convenience. Some people will want it and pay for it. If I was in the market, I probably would.
I agree in so far that plug-in charging shouldn't be an issue for most people.
Yet I can see the advantages for someone with a disability.
And what a lot don't seem to understand: at 11kW we aren't talking about high charging efficiency anyway. Meaning, you cannot assume close to 100% for cable based charging and talk about how much 90% loose on a full battery (like others here do).
Home charging us a reasonably thick cable. It’s not bad by any stretch but it’s more than an appliance cord.
Plus you just got home. You probably want to go inside and may be carrying packages or such, which you might have to juggle or put down to get the cable and plug in.
When it’s time to leave you have to unplug and then store the cable, leave it on the floor (trip hazard for others), or have installed an overhead cable system.
With wireless it’s all gone. Pull into you’re garage? You’re done. You were doing that anyway, so it’s no different. Ready to leave? Just back out. Again, same thing. Nothing extra.
Yeah it’s convenience. But it’s not a small win, it’s big. And it’s every time you use your car. Twice.
Your car can always charge. It can always precondition. You used to have to go to gas stations, now you don’t even have to plug in. It’s fully automatic and taken care of for you.
“You don’t need a remote. You can just get up to change the volume”. How well did that argument go over? Every TV has remotes. Buttons are hidden and effectively dead.
They're optimizing the cable you can trip over/have to walk around/remember both at home and at, eventually, parking lots.
guys, guys. They're optimizing: people with a lot of money being nagged.
Welcome to capitalism.
It's not just that; there's a new capability unlocked. You can now have self driving cars charge at remote places and come back without human interaction. Imagine you live in a place with no grid power
I have a robot vacuum that manages to do automated direct contact charging just fine. I don’t understand why wireless would be any easier. It seems more complex and less safe than a direct wired connection.
I also have a lot of trouble believing in the scenario of a neighborhood that has an automated charging station for EVs but no grid. That seems like very misplaced priorities.
Robo vacuum charging is almost inherently safe. They probably charge at something like 12V/2A. Voltage too low to penetrate skin, wattage too low to cause serious injury unless you’re really trying.
You can kind of just leave them exposed and live.
None of that applies to a 220V, 50A (or whatever amperage) charging. That can absolutely kill somebody; jet fuel may not melt steel beams, but 11,000W sure will.
You’d end up needing some kind of recess probably, and then getting cars to connect to it like planes refueling mid-flight is a nightmare. You could try some sort of USB-C like signaling before power is sent, but people are never going to enjoy “exposed 220V contacts that may or may not be live depending on if things malfunctioned”.
The point wasn’t that my robot vacuum is handling large current but that “moving device connects to power” is a solved problem. A car capable of driving itself onto this pad could as easily drive itself to a spot to plug in. Extendo-arm from the car could easily slot into an outlet in the floor. Or vice versa. Or a wall or pole.
Planes refueling mid flight is hardly an apt metaphor given the charging station isn’t moving at all and the car can move as slowly as needed.
This seems like one of those “reality has a surprising amount of detail” situations.
Surely getting something to autonomously without fail extend an arm and plug in for the lifespan of these vehicles vs just park in this allocated spot you would park in anyway is an obvious tradeoff.
It’s definitely a trade off but both options have a lot of real world concerns. If safeguards on the wireless pad fail you could easily cook an animal or start a fire. The bottom of the car now needs to be metal free to allow this to work. Distance matters which means if it charges your Porsche it might not be able to charge a Rivian and certainly not with the same efficiency.
I also frankly do not believe the 90% efficiency claim because it seems so much higher than any other wireless charging I’ve heard of.
This seems like one of those things that seems cool but is not generally practical. As a convenience for wealthy Porsche EV owners, sure. As a general purpose charging solution? I doubt it.
> A car capable of driving itself onto this pad could as easily drive itself to a spot to plug in. Extendo-arm from the car could easily slot into an outlet in the floor.
Those two things really aren't comparably difficult. Eg in the dumbest case for pads, you could make the pads slightly smaller than axle diameter (to prevent dead shorts) and have the car randomly jostle around the space until it detects current flow. I've seen some amateur systems that work vaguely like this. Some signal that charging is nearby, and then a semi-random search to find exposed contacts.
That's not going to cut it on a recessed outlet. Your odds of hitting it randomly are tiny, and it will probably the damage the port with enough repetitions of ramming it into the floor.
> Planes refueling mid flight is hardly an apt metaphor given the charging station isn’t moving at all and the car can move as slowly as needed.
Change your reference point to the plane carrying the fuel and they get an awful lot closer. The planes are moving a lot relative to the ground, they're moving very little relative to each other. I'm not sure if you've watched them doing it, but relative to each other it's actually a very slow process.
> Your odds of hitting it randomly are tiny, and it will probably the damage the port with enough repetitions of ramming it into the floor.
Why would it be random? The scenario here is self driving cars. Suddenly we are talking about random jostling instead of actually targeting.
> Change your reference point to the plane carrying the fuel and they get an awful lot closer. The planes are moving a lot relative to the ground, they're moving very little relative to each other. I'm not sure if you've watched them doing it, but relative to each other it's actually a very slow process.
What is your point here? I’m totally lost. You seem to be trying to hand-wave away the difficulty of refueling mid flight. The specific difficulty there is the fact that it’s happening at high velocity, not the difficulty of plugging a hose into a port. (Traditional mid air refueling is manually directed anyway.)
You are probably fully capable of fueling your car at a self serve gas station. Try doing the same at highway speed. Just reach out the window of the vehicle you are in and fill up your friend’s car from a gas can. Should be easy since the cars are “moving very little relative to each other”, right?
How does wireless charging unlock this usecase? Robot arms exist?
I guess if you see the video on the linked post, you'll see what the usecase is unlocked. A neighboor city with a wireless charger station or a road wireless charger station can receive a self driving car above it, charge the car and with some kind of NFC do the payment and goes back.
> the video on the linked post
The 3D rendered video of a car driving over the pad doesn’t really show anything unlocked. There are a lot of possible ways to build automated charging stations. This is not necessary tech for that scenario.
This is a lot better maintainable than a robot arm.
And the funny thing is China's already picked up the dropped torches elsewhere; Xiaomi's going to be launching a robotic arm for your garage by the end of this year to plug in for you. Tesla gave up on their charging tentacle, but, wellp.
https://carnewschina.com/2026/06/13/xiaomi-unveils-home-char...
Porsche’s induction charging strategy seems a lot smarter and much more reliable than a robot arm.
I don’t know. I’ve stopped using my wireless phone charger because it’s spotty. Sometimes it charges. Sometimes it doesn’t (or barely charges). Sometimes it wakes me up at night because it’s glitching in between charging and noncharging states and my phone feels the need to beep and wake me up.
I’ve seen similar issues with multiple watch chargers. “Oh, it didn’t charge overnight again.”
I’m not as sold on wireless charging as I once was.
Wall-E future here we come. Soon the people loader that lifts you from your sofa and plops you into the seat!
I think of this / feel this way when I ride my onewheel instead of walking
I want to know what mechanisms the car provides to ensure you're lined up to the mat correctly. Seems like a small target to hit.
Plenty of modern cars have all-round cameras that track what you've driven over. Probably pretty easy if it has that.
We already have several, see the Xiaomi SU7 lineup
This is something that isn't going to work for two practical reasons:
1. Losses remain very high for daily use.
2. Nobody is going to spend to install these propriety chargers except for millionaires that don't care about the costs.
This isn't a luxury charger; it is an exotic charger.
> Losses remain very high for daily use.
It's about the same as wired AC charging:
https://insideevs.com/features/711659/ev-charger-efficiency-...
the imaculate lifestyle aproaches, but then in the way of reality, will then prove to be just out of reach, with some new more minor and tedious 'inconvienience' taking on the roll of 'proof' in bieng a victim.