Yeah, running a 240V 50A outlet in a garage in most homes would be fairly cheap, since it's usually not going very far from the main panel. So might as well do it if you're already spending a huge chunk of change on an electric car.

The last time we hired an electrician to run about 30 feet from a panel to a new 50A sub-panel across the shop for a project was around $800 IIRC.

One thing I really don't get in the discussion around EVs and charging is, why are people so afraid of tripping the main breaker? If you have a total of e.g. 17 kW available and happen to go over, just reset the main breaker (or replace it in case it's still a traditional one). It's there precisely so that you wouldn't need to care about overloading the connection.

In my experience people get by with a 3x25A (17 kW available, matches approximately a 70A service in the US) while using the available power to

• heat/cool a single family home (in -20 °C weather mind you)
• run all appliances (including the oven, stove, dryer etc.)
• heat up a sauna
• charge an EV
• whatever else you typically would want to plug in, kettles and such

While it's true you can trip the main breaker if you have everything on at the same time, typically it never happens even if there are no lockouts in place preventing overuse. And it's not like tripping it causes any permanent harm.

Why is an electrical service upgrade constantly brought up as a solution when any home with >15 kW of available power won't need it? Is it against code to purposefully overcommit your mains in the US or something?

Edit: there were valid concerns raised over how long-lived the breakers are (probably won't be rated for tens of fault-condition related trips), also that these smaller service specs aren't as common as I've gathered from the media. That might have something to do with this at least. Thanks for the replies – it's been an interesting discussion.

Yep – US also doesn't generally do residential three-phase unlike many countries in the EU. A lot of garages around here have 3x16A 230V, not (only) due to the power requirements but because having three phases allows for simplest induction motors for things like blowers and circular saws. When you have three phases having a proper outlet in the garage starts making sense.

Around here (Finland more specifically) we have three-phase even in most apartments. My two bedroom apartment has a 3x25A main breaker, and two devices on 3x16A circuit's – the sauna stove and oven+stovetop. Most single-family homes have 3x25A or 3x36A as well.

US households are missing out on a lot of things due to their split-phase system.

Ohh! I spent some time in the U.S. and there are 230v mains available. They just have special plugs. All homes have 230v. It’s just not available through the shocked face plug.

The way that it works in most countries is that the breakers are per circuit in your wall. The breakers trip in order to prevent that single circuit from overheating and starting a fire in your walls.

Let’s say you have a wire that’s rated for 16amps. More than that and it becomes a fire risk just threw overheating. @230v that gives you 3680w per circuit.

If you have your industrial microwave, water heater, and car charger all going at the same time on that same circuit. This will draw way more than 3680w and thus would go over that 16a limit.

The breakers trips once you go over that 16a limit for safety. It’s a good thing. This all being said no sane electrician would put those three things on the same circuit. lol.

Circuit breakers are actually what enable you to safely over provision. Without them fires would just be a matter of time.

I know it works this way in the U.S. and Germany at least.

My wife had to try charging on a 120V outlet last winter. The plug couldn't even keep up with the battery heating requirements to actually start charging; the battery percentage was going DOWN while plugged in. It was -25°C outside though, so it's a specific situation, but it's actually why she had to try to charge; it's a trip we can easily do without charging in the summer.

I agree with this youtube comment:

As an electrician (in Australia), I agree with your basic premise. However, if you are asking me to install an EV charger, unless you tell me “I want it to charge slowly with a limited current capacity”, I am going to assume it is to charge an EV under ALL situations - fast to slow, for whoever may drive one today or in the future, even with a potential new homeowner. We generally do our work with the priority order (1) safety - nobody gets an electric shock and nothing catches fire; (2) avoidance of nuisance i.e. the thing you just installed doesn’t work and keeps tripping the breaker (3) avoiding needing replacement electrical work for at least 25 - 50 years

Also I live in a townhouse with no garage. Our charger is between the neighborhood sidewalk and our parking spaces, so I'd prefer keeping it plugged in as little as possible to minimize any issues with foot traffic (neighbors, delivery people, garbage pickup, etc). I've seen other townhouse EV owners literally run an extension cable over the sidewalk to do an L1 charge for their EV and that's just asking for trouble.

Any AC load you can throw at an EV is effectively “slow charging”.
My car supports a maximum of 9.6kw from an AC charger, but up to 150kw from DC fast chargers. Even with the fast charging, its not like a phone, it has active thermal management which will cool the battery and slow down the charging if it gets too hot. phones don’t really have that and is mainly why they degrade faster if quick charged.

What electric vehicle gets 5 miles/1.2kWh?

Most of the small ones.

Not talking about the circuits, but the main electrical connection to the grid. To me it often seems like there's reluctance in overcommitting overprovisioning that capacity: as an example, four 16A circuits on a 25A main breaker. Here that's quite common, but even in Tech connections videos I've seen him bring up smart electric cabinets or automatic load monitoring when putting enough capacity on the mains to possibly go over.

What I'm asking is, why bother? If you trip the mains by having too much load, just reset the breaker and be done with it. No need to automate things to not run into that situation, one will learn to not have the oven on while charging the car full blast. No need to gimp the charger amperage since you're running a new circuit anyway, and it's not like it's much different running a 20A circuit vs a 40A one. If that's 70% of your total available capacity, it doesn't matter – worst you have to do is walk downstairs and flip a switch.

Fuses sound antique compared to resettable circuit breakers. Though, if I remember correctly, your outlets have resettable breakers? Anyway, part of the wattage deficiency comes from the voltage being half of Europe's. The wires are similarly sized so they hit about the same max amperage (largely 15a for most circuits, 20a frequently in kitchens/garages/exterior outlets, 100-250a main breaker for the house) but halving the voltage halves the wattage available

In recent test of a German auto club they found out that it‘s cheaper/ more effective to charger faster. You loose a lot of energy if you load slow over hours.

This energy is taken by the electricity of the car. So, while charging the car is on and takes some Watts. There are just a few brands that have decoupled the charger circuit from the overall electric circuit of the car.

Can’t find the article now, but I think charging a PHEV through a standard power plug had about 20% energy lost. It was clearly visible that a charger is a good choice.

Edit: link https://www-adac-de.translate.goog/rund-ums-fahrzeug/elektromobilitaet/laden/ladeverluste-elektroauto-studie/?_x_tr_sl=de&_x_tr_tl=en&_x_tr_hl=de&_x_tr_pto=wapp

You‘ll loose

• ~10-30% AC 2.3kw Standard Power Plug
• ~ 5-10% DC 11kw Wallbox
• Internal car electronics are crucial: Is the loading circuit de-coupled or the entire car On?
• Temperature or pre-heating the battery before loading reduces losses at DC charging

This is not about me or you, this is "usually".

Yep – US also doesn't generally do residential three-phase unlike many countries in the EU. A lot of garages around here have 3x16A 230V, not (only) due to the power requirements but because having three phases allows for simplest induction motors for things like blowers and circular saws. When you have three phases having a proper outlet in the garage starts making sense.

Around here (Finland more specifically) we have three-phase even in most apartments. My two bedroom apartment has a 3x25A main breaker, and two devices on 3x16A circuit's – the sauna stove and oven+stovetop. Most single-family homes have 3x25A or 3x36A as well.

US households are missing out on a lot of things due to their split-phase system.

Car specific maybe? I was able to charge at -30C outside from a 120V outlet last winter.

ADHD guy here.

Wondering if these are reasons but need someone knowledgable to answer

• does the mains breaker have a limited amount of resets / duty cycle?
• is it bad for the whole house to trip sometimes? For me having to reset electronics, potential data loss etc makes it annoying.
• is there a potential for surging when the mains is flicked back on from everything starting simultaneously?

That depends on what is meant by usually. You seem to think it means "most daily situations," but I think it means "most house installations." Yes, a usual day in a person's life does not require L2. But the usual person does require L2 if they want to use their car like most people prefer to use their car. Once a week I need L2 charging because of all the stuff I do that isn't commuting. That is 1 day in a 7 day week, so usually I don't need L2. But I would not be able to have an EV if I didn't have L2 unless I had a second car (which I don't have). I think most people fall into this category, so the usual person needs L2 even if they don't usually need L2.

I'm not sure what you mean by this. Any modern US house would have a similar capability, it's just older homes that would struggle since there would never be a need for such high power devices in a garage.

Most older garages would only need enough power to run a single lightbulb, if it was slightly newer, maybe a low power automatic garage door opener.

It's the same in any country with buildings over 100 years old.

Are they somehow more expensive in the US? 40A 230V rated ones cost something like 30-50 € around here which doesn't feel that expensive to me. I'll admit it's considerably more expensive (~4x the price) than a standard breaker, but it's still more like a rounding error in overall costs.

Although EVSE's projection doesn't require you to periodically trip the GFCI so it doesn't get stuck, which is a major plus.

You seem to think it means "most daily situations," but I think it means "most house installations."

That's the opposite of what I think.

Once a week I need L2 charging because of all the stuff I do that isn't commuting.

No you don't. You go and do those things, then plug it in and charge it up over the next 6 days until it's fully charged again. If that is insufficient then you are not a typical usecase.