Wireless Charging

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Wireless charging feels like a total waste of energy in it's current state for phones, so I hope it's better for cars since it's much slower and creates more heat on phones.

Induction chargers lose 20 to 30 percent of energy in the form of heat vs 5 percent for conventional charging. That's manageable for a battery that's 15 Wh. I imagine it might get pretty hot for a battery 3000x bigger.

If you don’t have a human to plug it in, not much of a choice, especially if the alternative (mechanical arm) is more expensive than wireless charging (even accounting for energy loss)

The leading tech for car pads is stated around 90-92% efficiency last i checked. It's not nothing, but it better.

This. Wireless charging is for functionality, not for efficiency. If a fleet of this is running, AI can just drive over an inductive charging pad and that's it. Efficient enough to get charging. As for the waste of power, it's a sacrifice over other alternatives that costs more to make and maintain.

Batteries in Tesla cars are temperature regulated.

Double it as house or water heating and boom you’re good

German company Wiferion says its chargers can offer 93% efficiency. Telsa bought Wiferion

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Unless they're laying down in the pad the field dropoff would completely remove the energy transfer

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You realize the field emitter device is not in the car right?

I used to think this also (the 20-30 percent thing) but I keep reading [various articles](https://witricity.com/media/blog/what-is-efficiency-how-do-you-measure-it-and-why-should-you-care#:~:text=Wireless%20charging%20operates%20within%20a%20narrow%20band%20of,to%20spend%20time%20plugging%20and%20unplugging%20the%20vehicle.) about how it's now in the high 80's-90+% efficient range.

The efficiency of wireless EV charging is on par with that of Level 2 plug-in charging. https://witricity.com/media/blog/what-is-efficiency-how-do-you-measure-it-and-why-should-you-care

"The robotaxi has no plug" Got wall chargers installed at home? Can't use them. That supercharger network? Can't use it. 3rd party charging, nope, can't use that either. Just seems like an unnecessary handicap for the vehicle.

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For a corporate fleet it wouldn't be hard to have a human on the charging spots connecting the charger cable. You probably still need someone to make sure the car and interior is clean once or twice per day. Since wireless charging is slower that would result in fewer hours per day the car can be out on the roads generating revenue, right?

It won’t be parked in your driveway at home. It won’t be doing cross country trips to need a supercharger

That's pretty interesting, big if true/applicable to teslas. I was thinking they could do something like robo vacuums with a contact pad/dock and it just reverses into it until it clicks and starts charging.

Interesting. I thought they had given up on this.

This is nothing new…it’s induction

You know that wireless charging is slower? Source?

Obviously a big extreme but what if you need a long trip robotaxi? Or there's one nearby that's low on battery and the next closest is 20 minutes. Id love a swing by a super charger I'll plug it in for 5 min option.

Would you love it if your uber driver pulled into a gas station to fill up?

If it saved me 10 minutes? Sure. Edit: my main point is the added cost of a port and 10 ft of high voltage cable is negligible just add it. Could also staff someone at the super charger to plug in during peak times in major cities

Take a Robo3 or a RoboY.

“If everyone starts riding CyberCabs, global warming from ICE vehicle emissions will no longer be a thing. We need to fix that.”   — Elon Musk, probably

They actually showed something exactly like that

There’s a lot more than that involved in adding a charge port, even if you only want it to be capable of DC fast charging

Not really, there's already a charge converter for the inductive charger. Id rather have 50 on the road that have the ability to super charge during peak hours than 100 that are only inductive. It's also going to drastically reduce the rollout. Every city they can convince to give approval to now they have to build a station or at least lot with 20? 30? Inductive charging spots, and that's assuming you only put power to some of the spots. Just a lot of cost.

Supercharger stations cost a lot more, and have very serious infrastructure requirements (8 250 kW stalls is 2 MW, or a little over 4000 A at 480 V) And I’m pretty sure the plan is to have not that many inductive chargers, because if it’s even close to the 11 kW we get from L2 charging, and the battery is say, 15 kWh LFP, there’s a good few hours of low demand in the early morning hours where each charger could get 3-4 cars to 100% charge. You won’t need 20 charge pads until your fleet is insanely large

I was basing it off of the more standard public lvl 2 at like 6.6 kw. Honestly the real move would be to buy parking spaces from existing companies. Have like 2 spaces per lot and have them strategically places. That said time will tell.

That idea would be good but you’d have to somehow make it difficult for regular cars to park in those spots

This is the fastest wireless charging I’ve read about. https://newatlas.com/automotive/100-kw-fastest-wireless-ev-charging/ 100 kW is not too bad, but Tesla Supercharges gives you 250 kW so still a big difference.

How much energy it gonna lose by make it induction charging

Why would that result in them lying chest down in the ground?

Then you take a S/3/X/Y/CT instead.

>Induction chargers lose 20 to 30 percent of energy Not anymore. https://www.inductev.com/blog/why-wireless-ev-charging-is-superior-to-plugged-ev-charging-rmf44#:~:text=Wireless%20EV%20charging%20is%20not,the%20same%20efficiency%20of%2090%25.

What about magnetic pin charging as seen in smart watches and MacBook.

Your telling me a robot that was serving drinks, cannot plug in a cable?

I want that auto vacuum setup for my 3

Correct - it will never exist

It requires a machine or human to connect/disconnect

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$30,000 robot to plug in a cable? It's not a matter of something being possible, but a matter of cost effectiveness.

did you see the auto vacuum, the screen polishing arm.. These things will go to a depo to charge which should be able to some up with a solution.

I wish my Tesla charged like my Roomba. Auto park onto some contacts on the ground.

I keep having problems with the charging ports on a variety of phones. Wireless charging doesn't have a connecter that can wear, which is a significant advantage, or a cable that can get in the way. I think the combination of both would be ideal both for cars and phones.

Exactly. Magnetic pins are simple contact based and doesn't require any intervention from humans and also very efficient and faster way of charging.

They are making a very big claim, with very little data. What they are trying to claim is their (special sauce) resonators are as efficient as a wired connection, but this simply can not be true according to our knowledge of physics. Wired transfer will always be more efficient due to the a logarithmic decay as distance is added between the transmitter and the receiver. Their numbers may be true in a perfect lab environment, where there is 0 distance in their setup, but incorporating it into a consumer product means increasing that distance. For their statement to be true you would need to see lab values at a 0 distance better than a direct wired connection. Edit: For reference I’m an engineer who has done a **lot** of work in the fields of thermal, wireless, and battery consumer product design.

Did you also claim that Cybertruck would never exist?

$30,000 to plug in a fleet of cables doesn’t sound expensive. They don’t need 1 robot per car.

Automotive wireless charging is comparably efficient to wired charging, HEVO's solution for example is 90-95% grid-to-pack.

SAE J2954 WPT (wireless power transfer) standard has strict safety requirements.

Products like HEVO has metallic and live foreign object detection to safely prevent or discontinue charging should this occur.

I don't see why hiring a minimum wage worker to plug in cables would be less ideal than losing like 50% of the energy you put into the car for every car lol. The physical limitations of this just screams over optimism from teslas side.

There is a couple orders of magnitude difference between pitching an ugly car and pitching a self driving car…

Apparently Tesla bought Wiferion, kept the engineering team, and sold the operations and manufacturing to Puls.

Interesting! Given your background what is the state of the art grid to pack efficiency for automotive wireless tech today? How near to the physics based limit on efficiency are we today? In other words, whats the real world implications of decay over distance?

There would be another robotaxi that meets you for another leg. You swap cars and carry on while the first one heads to a charger.

SAE International produced the WPT (wireless power transfer) J2954 standard, independently verifying grid-to-pack efficiencies up to 94% with a 10" airgap (edit: [SAE website, Oct 2020](https://www.sae.org/news/2020/10/new-sae-wireless-charging-standard-is-ev-game-changer)) ([related article](https://www.canarymedia.com/articles/ev-charging/tesla-bets-76m-on-wireless-ev-charging-can-the-tech-go-mainstream)) HEVO's has stated average coil-to-coil efficiency is 97.5% at varying z air gap and xy misalignment following SAE requirements, delivering a 91-95% grid-to-pack efficiency for their 50 kW solution. InductEV makes similar claims for their 75kW modular solution, which is in use today to deliver 75kW to taxis and 300kW for transit busses \[supporting up to 450 kW for heavy vehicles\]. IIRC they support something like a 7-12" airgap, this technology is in use outside the lab.

Or you could just pay a guy minimum wage to plug in a few thousand cars a day

SAE International verified grid-to-pack WPT efficiencies up to 94% with a 10" airgap \[[Oct 2020](https://www.sae.org/news/2020/10/new-sae-wireless-charging-standard-is-ev-game-changer)\], comparable efficiency to wired. IIRC the company Tesla acquired had similar best-in-class efficiency. The link references an 11kW L2 level solution, HEVO has a 50 kW product, InductEV 75kW modules; it will be interesting to see what power level Tesla delivers.

Past investor day slides hinted at a home wireless charging solution, the cybertruck also has a stub out for an optional WPT pad; I'd be surprised if they don't offer a home wireless charging option for all vehicles \[eventually\].

HEVO claims 91-95%.

Wireless charging is comparably efficient to wired charging.

The same ONRL group also demonstrated 270 kW charging to a light-duty vehicle \[[article](https://www.ornl.gov/news/polyphase-wireless-power-transfer-system-achieves-270-kilowatt-charge-sets-another-world)\] *over a 4.75-inch gap*. cc: u/feurie u/alexeiw123. *\[InductEV can deliver up to 450kW today to heavy vehicles by using multiple 75kW receiver modules, an approach not really suitable for light-duty vehicles\]*

Should be worth noting the SAE standard is for “low duty” vehicles and maxes out at 11kw.

That’s some impressive tech, thanks sharing that.

Sure, that specific standard was targeted at L2 charging \[fine enough for off-hours recharging of the fleet\] or home charging. Purportedly current industry standards cover power levels up to 20 kW \[same source below\] As stated other vendors offer 50kw and 75kw solutions of similar efficiencies, suitable for opportunistic urban charging of light-duty vehicles. ONRL has also demonstrated (in the lab) 100 kW and 270 kW polyphasic solutions with 95% efficiency for light duty vehicles \[[june 2024](https://www.ornl.gov/news/polyphase-wireless-power-transfer-system-achieves-270-kilowatt-charge-sets-another-world)\]. No idea when that might be ready, but good to know a supercharger-level solution is feasible.

Right, you just mentioned examples of things that don’t have a cheaper autonomous alternative.  Charging does have a cheaper alternative, it’s called wireless charging.

You know what’s even cheaper? Wireless charging.

Whatever dude, your telling me you can vac a car but not plug in a charger you could use the same machine.. Routine 1.. plug in car, step 2 vac... and wait.. Induction is cool, but has losses and seems generally dumb when you think about the robots capabilities.

No, I actually put down a day 1 deposit. I got a refund a few months later when the novelty wore off. This is orders of magnitude more difficult and was promised back then too.

Stop repeating this absolute bullshit. It's absolutely insane to think that making a direct copper connection is comparable to going through two rectifies, an inverter, and copper coils. Like, perhaps you can go with "It's not a huge energy loss, it'll be fine" but saying it's comparable is just dumb.

Well on the factory floor, they're bolted down. And presumably, these working vehicles would be on wheels. Indexing is a major problem. See: the model 3 ramp. They had huge problems with misaligned panels because of it, and as I said, they were literally bolted down then lol. There's a lot better tech today, so I'm not saying it's impossible. But it certainly is a hard problem to solve. They showed that automatic cleaning service which seemed really smooth and easy but I cringe thinking a robot arm would delicately dust off the screen without damaging it.

EV adoption is still at an early stage. Most charging stations have not been built yet.

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Whatever dude, I’m an engineer trying to explain to you why certain solutions make sense from a cost standpoint, but feel free to ignore it and move on with your life.

The event last night showed a robot arm cleaning the interior. So they thought of that, not to say they can make that solution work at scale.

You're exactly right.

No,when talking high power charging you can have robotic charging at a (way) cheaper price than induction.

Not at high power, these claims have not yet been proved in a real life environment yet, except for some very expensive trials.

If you want to charge 75+ kW with induction you need a separate insane cooling hardware to be installed on the vehicle, because of all the energy loss. These solutions are nice and easy on paper but have not been proven yet as scale.

No choice, robot snake or Optimus is expensive and people will break them

Nikola Tesla provide it was possible over 100 years ago. I'm sure Tesla can figure it out and make it work.

Skeptical about this, there are no independent studies nor real world tests of this. To get over 90% efficiency, beating wired efficiency screams to me that these claims are Cherry picked. No data sets were offered nor methodology.

Even if hypothetically it didn't break 90%, that's still nowhere near 50%. And WPT is seeing real world value and use, for example (yes, [a press release](https://www.inductev.com/press-releases/sound-transit-to-go-wireless-in-seattle) because it's quick) Washington State now has 7 transit agencies using InductEV 's solution for opportunistic 300kW charging of transit busses at bus stops \[amongst other users\].

If rhey can get L2 10Kwh wireless charging going, it's a win!

It’s to make it waterproof