Why do EVs not use the full 3.12kW from a mains socket?

ROFL! "The typical cost of a home charge point is around £800."

Er.... £100 2nd hand on Ebay plus a bit of cable to connect it to the fusebox. Not £800.

I'll play the stright cow here. In the USofA, a "continous load" on a circuit is generall maxed at at _80 percent_ of the rated wire/circuit carrying capcity.

Reason: heat buildup.

I suspect, with no foundationwhatsever, the UK uses the same concepts.

I'm no expert in UK electrical regulations, but in other conversations, I'm pretty sure I've been told this is not the case. The reason is, in the UK, most homes are wired with a "ring" that can carry much more than 13 amps. So the wires and breaker are rated at higher currents. So each 13 amp load can actually draw 13 amps.

Also, in the UK, the protection device for everything plugged into an outlet, is in the device. They put a "fuse" in the connector itself.

Sounds pretty good to me. In conversations with brits who know about this stuff, they claim their electrical safety is much better than in the US. They don't seem to have a problem with tossing out the old every few decades, when they come up with something that is significantly better.

No idea what that's supposed to mean.

It does not, we wire things properly as we're a 1st world country. You can buy 3kW fanheaters for example. I've run one for several hours without anything bursting into flames.

We also have switches on our sockets, and sleeved pins. I guess that's why you still have the wimpy 120V in most circuits.

Danny, aren't you glad you offered some help?

I have an old British plug here, fused. I just opened it for a check, and the fuse is rated 13A.

With a continuous load of 13A, that fuse will blow. I don't know if in hours, or days, or minutes, but it will blow.

I don't think that's right. A 13A fuse should not blow at 13A, but may blow above 13A. It may take some time.

Why above, but not at 13A? These things are not hugely precise. I know you can't count on a 13A fuse to blow at 14A. I would not expect to draw 13A from a 13A circuit and never have problems. I guess if you go through a few 13A fuses, you will eventually find a 13.5A fuse and life will be good.

...

A UK 13A fuse will actually pass about 20A indefinitely.

Fuses are not precision things. For that you need an electromagnetic current limiter switch. They simply blow faster the higher the current is. Given time, they will eventually blow even at half the rated current.

Commonality with other 230/240V markets? The UK is unusual in having standard sockets rated at more than 10A.

Sylvia.

I stand corrected.

Although they are nominally rated at 13A modern sockets are seldom happy with anything much beyond 10A as a continuous load. I have seen plenty of extension sockets destroyed by having a fan heater plugged in.

In a cold room a 3kW fan heater doesn't switch it off until the thermostat is satisfied which can be a few hours by which time the plastic around the socket has melted.

At full 13A load current for an extended period plugs can also get uncomfortably hot due to the UK having a mains fuse in them.

Short term 3kW loads are OK like kettles for a few minutes (but even that is now deprecated all modern kettles are 2.4kW aka 10A).

I suspect that they use less beryllium in the spring contacts than they did in the old days when nominally 13A sockets were real 13A sockets.

Actually, most of Europe use "Type E" sockets which are 16A x 220V = 3.52kW.

That's because your extension was shit. I've never had that happen. The only one I ever saw melted was one with two washing machines and two tumble dryers plugged in at once.

So.... see the plug on the actual fanheater, that can take 13A continuously....

Only if you decide to see if you can hold onto the pins afterwards.

BULLSHIT! Decent kettles are 3kW. A Dualit Lite for example. Why the f*ck would you want to take longer to make your coffee?

Irrelevant, it's the fuse which makes the heat. Can't they make fusewire of something which creates less heat, but melts easier? Then again, plugs used to sensibly have a little vent at the top. Probably removed for some health and softy reason.

In the old days they were 15A at 250V and had big juicy round pins, which was 3.75kW. People had hobs running off sockets.

Pointless to worry about sockets. People seldom need to charge their EV in any room, except the garage. If you are serious about EV, you should run a dedicated line from the circuit box anyway. There are much higher power charger available. For example, the Rivian charger goes up to 50A at 220V.

Which is a big fail in the US. We have 15 amp circuits and devices plugged in, which can cause fires if a short develops that passes less current than the circuit breaker, but is over the rating for the device. I've never really understood the idea of letting any number of devices be plugged into a string of outlets, with any size loads. Very few people in the US have any idea what circuits their outlets are on. So plug in a heater in this room, plug in a heater in that room... all on the same circuit and the line is overloaded.

At some point it works like Green Acres!

You make that sound like a lot. My car will take 72 A at 240V... er, make that 277 volts. There's a way to get 277 volts from a three phase circuit which Tesla allowed for. Meanwhile, I ended up being happy charging from 120V, 15A outlets.

I wouldn't mind having a 30A, 240V circuit to charge from. It would allow the stupid off-peak charging controls to work properly... well, most of the time. They don't ever stop the charging, other than reaching the charge limit. You either get to start the charging when you specify, and it charges to completion, or you specify when you'd "like" it to be finished, and it plans a charging start time. Neither of these actually works around the off-peak times. You have to do a bit of math for that.

It's safer, more reliable & usually cheaper than radials. That equals better.

Correct. And most US wiring is banned by UK regs.

or 2. I've not seen that be a problem. Bear in mind our socket circuits are mostly 240v 32A continuous, and they can run much more for short times. I can think of no reason to need more than that upstairs in the average house.

yes.

No, not a problem.

It hasn't

Someone doesn't know much about uk housing.