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Comment by rad_gruchalski | Hacker News Reader

How long does it take to charge this thing?

Charge current can be scaled with battery capacity, so it should be the same as any battery of the same chemistry if you have a powerful enough charger.

Probably twice as long as the battery it replaced (assuming twice the range). You can still stop and recharge every 300 miles if you want to. Ultimately you're gonna spend the same amount of time charging to get the same distance. This just means you could go out 300 miles and back without stopping for a charge at all. The advantage of this though is that you can at least start with 600 miles of range from your home. You'd probably only ever have to charge it overnight, because that's a solid 12 hours of driving. So long as your hotel has a charger you can use, you're basically never stopping to fuel up on a road trip as a single driver.

Does it really matter if it has a range of 1200 kilometers ? I would have to charge this car once every 3-4 years or so.

I would have to charge it every 3 weeks.

sounds like you dont need a car

It’a convenient to have when I need it. I have a tiny car that cost me very little in taxes and insurance. Slightly more than a car sharing subscription would cost but available whenever I want without having to reserve it in advance.

If you drive 300Km per year, you probably shouldn't own a car.

~700 miles is the magic point at which charging times can be significantly extended to simply be overnight.

Problem’s without fast charging many EVs are already there, even in europe.

A standard plug is 3.6kW, overnight that’s under 30kWh (probably significantly so as charging slows down a lot above 80%). To charge a model s 100 overnight you need a 22kW charger (3-phase 400V 32A). In europe that’s the biggest you can get in a residential setting I think.

For double that you’d need a fast DC charger, I don’t think that’a available for residential use.

I'm a bit confused by your need of 22kW to get "overnight" charge of 100kW. Wouldn't you have that 100kW in <5 hours with a 22kW charger? I would imagine most people think of "overnight" as >5 hours, probably closer to 8. So a 22kW charger is way better than overnight in those markets where that's reasonably available.

You'd get pretty close to "overnight" charging in the US as well. Its often not too hard to add a 48A 240V EVSE into a garage here, 8 hours would get you ~92kWh of charging power. I'm not entirely sure what charging efficiencies look like on a Model S, and 92kWh is only 92% of of the battery, but chances are you weren't pulling into your garage at 0% charge anyways.

> I'm a bit confused by your need of 22kW to get "overnight" charge of 100kW. Wouldn't you have that 100kW in <5 hours with a 22kW charger?

Yes. Because 5 < 8 it works for an overnight charge. The chargers I’ve seen below that are 11kW, which is not sufficient, hence “you need a 22”, because the model below that does not suffice. Though it is of course possible intermediate models do exist and I’m unaware of them. Tho I guess it would make sense for american residential power supply to top out somewhere inbetween.

And do remember, charge speed is not constant and slows down drastically as levels close in on full.

> You'd get pretty close to "overnight" charging in the US as well.

The context of the discussion is the ability to charge a 200kW battery overnight yes? My point is overnighting 100kW is already a pretty heavy requirement.

Although I’m not sure that’s much if an issue, doing >700mi multiple days back to back in a car and going home every time seems quite the rare use-case, usually it’s more of a road trip situation so you could find fast DC stations on the way and your overnight would not be critical.

Ah, I didn't realize there was essentially a jump all the way from 11 to 22 without much in-between, I kind of assumed there would be somewhat a range that would be common. I'm not too familiar with what EVSE chargers are common in Europe.

It’s a pretty logical consequence of delivery, basically in residential settings these days you’ve got:

- 230V 16A (3.6), that’s your bog-standard plug

- 230V 32A (7.2), that’s your high-amp, usually for things like AC, electric cooktops and ovens, driers, …

- 3-phase 400V 16A (11kW), same as above but for the rarer cases where 7.2 is not enough (e.g. high-end electric ranges commonly exceed 7.2 if they have high-power burners or lots of them), as well as higher-end tinkering / DIY tools, it used to be very common but really drew down over time as single-phase power & reliability increased and simplified setup, I have not looked but I expect EVs are leading (or will lead) to a renaissance of residential 3-phase.

- 3-phase 400V 32A (22kW), same as above with larger wires, AFAIK it’s basically the biggest supply you can get in a home or appartment.

Its interesting to me as in the residential US you'll see 15A/20A for common outlets/lights, then 30A/40A common for large appliances, and finally 50A circuits being somewhat rare but not entirely uncommon. There's quite a range of common amperages instead of just two different common amperages. I had just kind of assumed there would be variability of amperages in Europe as well.

Thanks for sharing!

Twice the capacity, twice the charge time (more or less).

How much does it take to cool this thing is my question

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