There’s a queue coming for Tesla charging | Hacker News Reader

There’s a queue coming for Tesla charging

spectrum.ieee.org

20 pointssamizdis74 comments

I don't care that I'll be competing for more cars at Superchargers. What I care about is their charging speeds. I'd be perfectly fine waiting for a Porsche Taycan to charge at 270kW, but I'd be really really annoyed waiting for a Chevy Bolt to charge at 50kW.

Here's a Taycan charging at 134 kW on a Tesla charger:

https://www.youtube.com/watch?v=L0F42jY3dD8

The charger claims to be rated for 1000 volts but either the Taycan isn't requesting enough volts or the charger isn't delivering them.

The focus on profitability seems strange given that gas stations aren't profitable from gas sales either. Gas stations make their money off of their convenience items.

You buy a franchise not to sell gas, but to lure customers to your convenience store.

Until charging times come down significantly, cafes and restaurants seem like natural partners for charging parks.

> ...cafes and restaurants seem like natural partners for charging parks.

$30 Avocado toast and $15 lattes.

Is that really true? The gas stations around me (in the middle of a city) are generally pretty empty inside, but full of cars filling up. They also sell gas for a few cents higher. It seems like it's a mix of the two strategies.

That's my understanding, yes. The profit margins on the convenience items are just so much higher. 20oz bottle of soda? $2. Wholesale price, probably under $0.50.

On average it isn't true. The average profit margin is 1.4% for gas stations in the US. Clearly the majority are not making much money on gas. Presumably that low average could mean for many gas is a loss leader.

Which is greater than zero, contra the top-level comment.

not actually contra. Those extra cents selling at retail prices need a lot of volume to break even given employees, property taxes, maintenance. That's why there is always something on the property to sell- convenience store, car mechanic garage, car wash, even whole restaurants sometimes.

It will be even more true for EVs because the charging times are longer. You won't stop in the convenience store while you're charging your car, you'll want to charge your car while you're at a store or out to eat because it takes longer to charge than to get gas.

IMHO the charger networks are a short-term solution and will ultimately go away. It's not that they are all making money by marking up electrons, it's that they're inconvenient.

I know people that have "all the apps" installed on their phone because they want to use whatever charger is nearby, not necessarily one on a particular network. As these things become more ubiquitous, people are going to want to pay via cash or credit in addition to using their phone. Your local restaurant doesn't need their chargers to be on a national network, they need them to be run by a local guy who also handles maintenance - like arcade game operators in the 80's or your local vending machine company today.

Cafes and restaurants have pretty low margins, so I wouldn’t expect them to have capital available to retrofit chargers.

The capital can come from elsewhere. If the location of the cafe/restaurant is good enough, it is likely cheaper to add a charger + small convenience store to an existing cafe/restaurant, than to build a new restaurant when building a new charger.

Even in a hypothetical world where there are as many electric stations as gas stations, the wait seems like a real pain point. I won’t buy an EV until I live somewhere I can charge it at home, and even then I’d rather take a gas car on road trips.

What’s that telephone operator math problem about how adding just a few more incoming to the queue increases average wait times astronomically or something?

The key issue is chargers are too expensive.

A home charger usually consists of a $5 relay, a $1 earth fault clamp and a $1 microcontroller. Yet somehow a home EV charger is $300+!

Home chargers could easily be designed to just plug into regular 30 amp 6.6 kilowatt tumble dryer outlets, for no additional cost.

Fast chargers are also too expensive. The main expense is high power switching electronics, but the core MOSFET's and inductors are super cheap. For example this[1] part can switch about 70 kilowatts for just $15. A basic 3 phase -> DC charger can be built with one of those, a few capacitors, an inductor, 7 power diodes, fan, heatsink and a microcontroller.

So why do commercial DC fast chargers only start at $25k??

[1]: https://www.mouser.co.uk/ProductDetail/Infineon-Technologies...

I'd guess at least partially for the same reason that a Cessna 172 costs $80k in parts and retails for $400k. A large part of the sale price goes to a bank account titled "in case of lawsuit." Someone needs to pay the lawyers when you get sued for a fire, etc...

Just the cord for a 30-amp EVSE costs $200, so I think you are slightly underestimating the bill of materials. The pricing is fairly consistent with outdoor-rated generator cords, which are $2.50/foot for 10/4.

so a 10 foot cord should be $25...

The wholesale cost of the copper for 10 feet @30 amps is $9. The rest is plastic, manufacturing & logistics costs.

I still doubt your analysis, however if you think you have identified an interchangeable consumer product with growing demand, for which the incumbent sellers have excessive margins, the rational thing for you to do is enter that business.

We just did a little 5 hour road trip this weekend to test the tesla charging. And it was awesome.

What I don't understand is how these small towns are not fighting for one of these chargers to be installed in there parking lots.

Every one of these chargers had people in the restaurants, or stores near these chargers.

If I lived in one of these towns I would setup taco trucks right next to one of these chargers.

At some point all of these chargers are going to have to start charging an equivalent to the gas tax to maintain the roads. EVs are heavier than their ICE equivalent.

I know some politicians want a mileage fee paid at registration but that is a privacy issue and problematic for low income folks.

If we double the weight of all passenger vehicles, how would the damage they cause compare to large trucks? IIRC the ratio is currently 1:5000 to 1:10000 but trucks don't pay thousands of times more for registration or tax on fuel.

I would guess that large trucks don’t drive on a large fraction of the roads, mostly staying limited to highways and stuff like that.

No they don't, but they do pay a use tax on the fuel. Electrics aren't paying anything other than registration.

Totally. I'm just wondering if, given we know they don't currently assign costs appropriately, would they start when electric vehicles become the norm? If not, how far off would they be compared to now?

While were at it, I've read heavy transport doesn't pay anything like proportional to wear and tear; if so that would seem to be more important to fix, at least at first glance.

I'm fine with this as long as the "some point" is when new ICE vehicle registrations are no longer allowed. Until then, we should just raise the gas tax as necessary to keep maintaining the roads.

When electric can actually replace ICE for all uses. They are a long way from that still. If you live in an apartment, the recharge time is still too high for daily rural use or even many needs.

It's a completely trivial difference compared to the damage that large trucks do. Damage to the road is proportional to the fourth power of weight per axle. Cars, and even SUVs, with or without a battery, are a rounding error.

With that said, yes, there would still need to be some to ensure the roads exist at all, and for the damage that happens irrespective of usage (like from weather, shifting ground, etc).

I believe that many people will do what I did - install a charger at home. Charge your car while you sleep. No inconvenience, no hidden fees. Which means that the charging industry needs to only serve a fraction of what gas stations currently do.

The only time that I care about superchargers is on a long trip.

Incidentally OCPP is a total mess. I looked at what it takes to implement it a couple of years ago. What they really need are some reference implementations. Because as it stands you just code something up according to the (rather complicated) spec, and then have to deal with interoperating with everyone who read the spec differently. Guess how well that works?

It will also make solar even more attractive.

Solar is not great for over-night charging...

Most people buy solar panels with energy storage.

I am getting solar with battery (in Texas) and I asked all the companies I spoke to when collecting estimates. They said < 10% do. Solar saves you money on the electrical bill and has a chance of breaking even over time. Storage doesn't nearly as much since most people sleep a large portion of the night.

Additionally, I suspect you severely underestimate the additional cost ($10k in hardware alone [2], and that is before you get to permits and labor) and severely overestimate the average American family's ability to pay it [1].

[1] https://www.google.com/search?q=median+income+usa

[2] https://www.buildwithrise.com/stories/tesla-powerwall2-basic...

One of the big things of the "green" crowd is that EV batteries can be used as storage for absorbing excess solar/wind energy, and maybe even put it back into the grid. Basically the opposite of your suggestion.

For solar, cars should be charged around noon. Overnight charging is ideal if we go nuclear.

Now I am talking about global scale, on an individual scale, everyone does what's best for them. For example, if you have net metering, having solar panels and charging overnight makes a lot of sense. Having batteries at home and emptying your home battery into your car battery during the night can also make sense depending on what kind of contract you have with you utilities and the kind of subsidies you can pretend to.

Anyways, most of the people I know (not in the US) with solar panels don't have energy storage, because they have net metering, or even better, they sometimes sell for more than they buy per kWh.

Is installing a charger economical for the average car buyer? I assume a high amp circuit install from an electrician is something like saving up another down payment. Maybe it can be rolled into the 84 month auto loans or whatever crazy length they are up to now.

Sometimes they are subsidies available to install them.

Most municipalities allow homeowners to do their own electrical work, assuming you apply for the appropriate permits and have your work inspected.

If you already have a subpanel in your garage, it's not complicated to add a 240V 50A receptacle. Depending on the scope of the work, it can be done for less than a couple hundred bucks in materials.

The everyman solution may turn out to be something like 240V 20A on an existing wire run. Just a new breaker & outlet, $20 in parts and 15 minutes labor?

11kW is nice, but NEMA 6-20 is good for 4kW or ~14 miles per hour, or 120-150 miles per night.

That's a good idea in theory, but you'd have to block off all the 120V outlets on the same circuit.

If the existing breaker is 15A, you need a NEMA 6-15, which is 2.9 kW.

It cost me about $500 for an electrician to run a 30 amp circuit to my garage, and $200 for a NEMA 14-30 compatible EVSE.

You can buy a charger and have an electrician install it on a new circuit for under $1000 total.

There are many, MANY people living in old high-rises. This is a complex infrastructure problem however you look at it. Not to mention the potential safety risks, depending on exactly how much power the car needs to draw to fully charge in ~8 hours.

Most people aren't fully charging their car every day.

I have a 220v 24 amp plug for my car and it charges ~22 MPH, which typically covers my driving for the day.

High rises need maybe a dozen of these chargers with load sharing so multiple cars can be on the same circuit.

>I believe that many people will do what I did - install a charger at home

This assumes:

1. You have a home and park in the exact same spot every day, and the option to install a charger

2. Your home's electrical network is able to handle the extra power from charging an EV

3. Your driving habits do not involve long distances or refuelling/recharging.

This article is about DC fast charging, which is absolutely critical for long trips, and not supposed to be used at all for local travel. There's basically zero overlap between use cases for them and for home chargers. Having a home charger doesn't help one bit when you're 300 miles away from home and now need to charge back up to drive 300 more miles.

Timely: I sit here waiting for an electrician to turn up to install power on our 50 acre property 3 hours north of Toronto. We have a 14-30 outlet in our house in the city, we use that to get around 35-40km/hr of charge in our driveway. That cost around $1500 (CAD) to install.

Up here, it's a different story. Our power comes in via the lake. It then goes to a transformer, it then goes to our metre which has a 200amp breaker on it. From there, it currently goes into the house.

In a few hours, it'll split off at the meter and head up a 150m hill where we'll be installing a 100amp outdoor panel with a 14-50 outdoor outlet. In the winter we cannot drive down this hill, so we need to charge up the top. It's a lot of work to do this, total cost is going to be around 8-9k, but from my perspective, it's an infrastructure cost and no matter what this makes us less dependant on fossil fuels and more independent. Our nearest gas station is around 20 minutes away, so we often have concerns about forgetting to gas up and then maybe struggling to get back to the gas station. While it's never happened, i love being able to charge at home.

$1500 ($1200 USD) seems pretty extreme to install a dryer plug. Were there hidden challenges?

Yeah, mostly the inflation of living in toronto.

I always thought it would be cool if they did in-road charging, like a slot car.

Or, at least have this feature at the charging stations - instead aof a group of ~8 pods with typical cable connection trope like that of a gas-line seems like it could have been improved upon? How complex are the actual charging "pumps"?

Finally, It would be really interesting if some scrappy engineer in a city with overhead MUNI power lines to add a pole to a tesla to slurp power off those line (although clearly they would be fined - but it would be a cool PoC-hack.

> How complex are the actual charging "pumps"?

150 kW per supercharger.

So your typical 8-pod supercharger needs to supply 1.2 MW, or roughly the same amount of power as 1000-typical US homes. EDIT: And now to build a thick enough cable that is weather-proofed and idiot-proof, so that no one kills themselves touching that wire... in all weather conditions (hot, cold, rain, snow, sleet), and... yeah... its actually kinda scary if you think about it.

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Yeah, in terms of "MW of fuel delivered per second", a gas station pumping gasoline is surprisingly efficient and simple. Doing it purely electrically, even at a much slower rate (30 minute charge times) is surprisingly complex.

Wow! 150kW. The chargers I use now are 7kW max. I wonder what kind of stress that puts on the batteries.

It's definitely harder on the batteries than regular L1/L2 charging, but it looks like maybe a low single digit difference in capacity after 50K miles, at least per https://www.energy.gov/sites/prod/files/2015/01/f19/dcfc_stu...

I think most stalls are actually shared so when your neighboring stall is occupied you'll get less power. Stations are more crowded these days so it's getting common. Anyway, it doesn't actually diminish your argument, especially as 16-pod+ supercharging stations exist.

https://en.wikipedia.org/wiki/Tesla_Supercharger "When both pairs of Tesla Supercharger station stalls (A and B) are occupied, they share the available power of up to 150 kW."

I've often wondered how effective a large induction loop would be in tapping power off of transmisison lines.

The transmission lines are designed to minimize the H-field radiation, so they're actively working against you trying to couple via the H-field.

Apparently people just do not understand how much power a car uses.

Bro you just need some solar panels on top all this charging stuff is for the birds.

I swear I’ve seen photos of an EV that was hacked that way like 5 years ago. Maybe an early model S?

It was a Prius. https://thebolditalic.com/hacked-prius-running-on-muni-power...

Thank you!

Fantastic! Thanks!

I am surprised there hasnt been more power-pirates in SF - like to power your home server rack...

But if the FN buses cant eat 400A all the time - Maybe start Muni-Hosting ;-)

I wonder what Muni's power bill is (and their rate)

> I always thought it would be cool if they did in-road charging, like a slot car.

There do seem to be people working towards it, or at least giving it some serious thought [1], and there's at least one proposed pilot/experimental scheme, such as [2] in Indiana.

[1] https://news.cornell.edu/stories/2021/04/research-paves-way-...

[2] https://www.greencarreports.com/news/1132979_wireless-ev-cha...

https://www.youtube.com/watch?v=27100u7IcII like this for trucks in Sweden?

It will be "OK" if we redefine what it means to be an American consumer.

Right now, there are still serious issues to EV charging at range.

When we have an EV system that can power our trucking system in any serious fashion, the consumer transportation question will seem minimal and facile.

I hate to say it, but as a Tesla owner there's a deep current of concern trolling pervading this genre.

People who didn't buy Teslas and who don't use superchargers have, well, way too much to say about what Tesla "should" do with its superchargers and how it will effect those people who don't use them and didn't buy a compatible product. I mean, guys...

That said: I agree that open access to chargers is a good thing for everyone and that it accelerates the day when these things are as routine as gas stations. But good grief everyone, don't pretend to be dispassionate observers, you just want access to superchargers.

> didn't buy a compatible product ... But good grief everyone, don't pretend to be dispassionate observers, you just want access to superchargers.

No, what I want is for EV infrastructure to have the same utility as ICE infrastructure. I can fuel my ICE vehicle at any fueling station, no matter the brand of the station or the brand of the car. Similarly, I should be able to charge my EV at any charging station.

Tesla switched to CCS in Europe a few years ago and they've just recently opened an initial 10 charging sites in the Netherlands to all EVs. That's the benefit of a common standard.

All other manufacturers have switched to CCS in North America. Tesla is the last remaining holdout. Balkanized charging infrastructure is just plain dumb and no good for anyone. Incompatible plugs and brand exclusive chargers just make EVs worse.

I think this is a perfect scenario for some subsidized Federal infrastructure spending. I revel in the knee jerk bristling conservatives experienced as they read my first sentence. Much like turnpike service centers that you see in the East, EV service centers could be built along the interstates and could offer charging, basic vehicle services, restrooms, and even convenience stores. They could be expansions upon existing rest areas, and would be open for all vehicles. Would be nice if Tesla didn't have to do it all themselves, since they currently basically plop chargers into lots and provide zero services. It is luck of the draw whether you can actually use a bathroom or wash your windshield while charging your Tesla.

Near Seattle, the government can't even keep normal rest stops open.

In addition, we already have that. I've stopped in DuPont, WA for charge and teriyaki. The charger was subsidized.

In nearby Oregon we don't have that. Except for the part about the government having difficulty keeping rest stations open. We have that.

Sidenote: If there's one thing I hate, it's when the headline tells me if "It's OK". It just screams soft propaganda to me.

Glad I wasn't the only one bothered by that, it must be a recent(-ish) trend, I keep reading it more and more lately.

and that's a good thing, here's why

It grated on me, too, but I left the headline as it was out of some misplaced respect for Spectrum (which seems to have become more clickbaity since its redesign of a few months ago). However, given your comment and others supporting it, I've removed the offending bit.

Please don't pick the most provocative thing in a headline or article and then copy it into the threads to complain about it. The most provocative thing is nearly always something shallow and barely (if at all) related. This leads to shallow/indignant discussions, which are the opposite of what we're going for here.

It's particularly important because shallow/indignant comments tend to get a lot of upvotes (this is the main weakness of the upvoting system), which means that they end up at the top of threads, choking out more interesting discussion. That's where this one was when I saw it; I've marked it off topic now.

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