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Comment by sp332 | Hacker News Reader

I get nervous just thinking about the amperage necessary to add 300 miles of range in 10 minutes.

Back of the envelope calculation to charge 100KWh battery in 10 minutes is about 750A [1] assuming 100% efficiency at 800V (back of the envelope optimism). Tesla Superchargers are already capable of 800A and Porsche is already using 800V. So it doesn't seem that much crazier than what we're already doing.

[1] 100KWh * 1000(W/Kw) / 800V * 6 (10min/hr) = 750A

That's not as bad as I thought. There are already water-cooled CC2 charging cables that can handle 500A as long as the radiator system is up to the task. Hopefully by 2024 we'll get there.

As long as the voltage is high enough the amperage can be made entirely bearable.

10MW (about 14000 hp) can be moved with just 100 amps at 100kv. Most houses have something like 100 amp service from the power company. At 1000kv that's only 10 amps. 10MW for 10 min is about 1500kwh or enough to charge some 15 teslas approx to full.

The power levels you're talking about are big compared to household stuff, but kind of a joke compared to industrial processes.

> 100kv [...] 1000kv

Don't those voltages leak like crazy across things which a normal person would consider as a safe insulator?

E.g. might some regular dirt on a plastic charging cable leak it into your hands?

If you're considering those sort of voltages you might as well look into just using liquid nitrogen cooled cables and super-conducting cables.

Liquid nitrogen can be made from the air on-site if needed, and is a hell of a lot easier to handle then hundreds or thousands of volts.

I've never heard of "leaking", but higher voltages are more likely to cause arc blasts. Usually that only happens when a switch is thrown.

Is it possible to make a cable safe enough for people to be holding at 100kv?

Why copy the UX of a gas pump, maybe we can go back to the luxury of staying in your car while the pump is operated by an employee/robot -- pop the charge port open and the "pump" steers itself and locks in.

Thought I saw a Jalopnik article about Bentley or Rolls Royce inventing that exact thing, but I can't find it now. The idea being, if you're a billionaire, you don't want to do something low class like plugging in your car.

You can't have a 10kV or 100kV charging station being handled by the general public to charge their cars! That kind of voltage needs specialised equipment and is extremely dangerous.

There's no such thing as a consumer grade 11KV insulated cable.

It doesn't necessarily have to be a cable. It could be rigid. You could even have a platform which moves the car up to the charger. I could see some sort of telescoping arm made of teflon though.

Do you think these 100kv cables are unusable?

https://www.schleich.com/en/product/high-voltage-cables-en/

I mean you would need some smarts to ensure the leads are never exposed when active but otherwise I don't see the issue.

Those do not carry enough current to charge a car faster, those are not the 100kv cables you’ll need here

Of course. They can only handle about 1mw, but they are thin and could be scaled up.

Er... if you say so

Yes, it’s a lot. But, people are going to have to get used to the idea of large voltages and anperages, in the same way that we don’t really worry about Fay to day handling of large volumes of highly explosive liquid (petroleum).

Leaking a few drops of gasoline probably won't do any damage. Shorting or arcing 800V is several levels of "nope" above that. You can be dead in a fraction of a second.

Ehhh that is not a fair comparison... if you get some petroleum on your hand there is no immediate danger as long as you are not near an open flame. Even if you do manage to light yourself on fire you have a decent chance of surviving.

If you get some kilovolts backed by 100 amps on your hands you are pretty much instantly dead.

Every day since you were born you have been near enough electricity to kill you instantly. We have good safety measures in place already after working with it for over a century. Petroleum is no different in that sense. Fuses are pretty good at protecting us. The major difference is that when someone crashes into a gas station lots of people can die from the explosion. If someone crashes into a charging station that’s just not the case.

My point is, we are happy to deal with dangerous and deadly things in our everyday life, why is this any different?

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