There are two ways you can charge an EV at home
Maybe some EVs can plug-in to a 3 phase AC socket i.e. no charger? Not seen one near where I work.
I have the house prewired for 3 phase, and it would be 3×80A i.e. 55kW, minus what the house “might” draw, and there is a calculation which an electrician is supposed to do, but you can DIY install it, but then you don’t get any grants 
I dont know how (or whether) a charger measures the house draw and scales down its output limit based on that; obviously it is possible, but do they? AFAIK they don’t; the installer makes the above calculation and adjusts the charger’s ceiling.
I know France has 3 phase historically commonly (a friend has a house there which was 3 phase in the 1950s; the sockets are still there but now dead) but here I would be charged (no pun intended) at least 5k for running a 3m connection to a cable in the street, plus other work so totalling a good 10k.
I know France has 3 phase historically commonly
Both our homes were wired for three-phase. It serves no useful purpose (unless you need the current, which we don’t), and it’s a pain for several reasons:
- current is limited per phase, so you can be way below your subscribed capacity and still have the main breaker trip. It requires very careful balancing of loads across phases and even then you can never get it 100% right
- you have no idea which sockets (and hence rooms) can “see” each other. I wanted to use ethernet-over-power to reach into the basement but you can’t without knowing that
We changed one house to single-phase, but it’s complicated because you have to arrange to have EDF and your own electrician on site at the same time. Given the general impossibility of getting anyone to schedule anything and then stick to it in France, that is best avoided.
So for our main home, we are still on three phase.
you have no idea which sockets (and hence rooms) can “see” each other. I wanted to use ethernet-over-power to reach into the basement but you can’t without knowing that
You can fix that by connecting 1000pF capacitors (obviously mains rated) across the phases You could stick them inside one 3 phase plug. Mind you, ETH over mains is generally 10x to 100x slower than the spec on the product. Another topic…
So the house in France I saw must have been converted to single phase.
I have 3 phase coming into the house, which then split onto 3 bus bars. The problem johnh point out, comes when you try to cut cost on the abonnement (standing charge) eg if you contract with your electricity supplier for 12Kva on each phase and on one of the bus bars you try to use more than what there is. If you have your heating, hot water, and say a cooker all being fed by the same bus bar it clicks off.
It’s a simple fix, move up to the next abonnement level. It takes 5 minutes with Enedis. An electrician can do it but they need to communicate with the energy supplier because of the extra charge. But they can see it on Linky now.
Adding a 7kw car charging unit in you garage costs around €300 through either energy suppliers or car accessory companies like Feu Vert. Of course your bus bar needs to be able to supply the 7kw as well as whatever else you are using on that bar.
Some companies now are offering battery systems whereas you recharge the batteries at say 3Kw per hour and then a bit like a capacitor you charge your car at 7kw/h as needed. This can save an increase in the abonnement but it is becoming popular due to solar panels and wind turbines in homes.
This is really very simple if you split the “charger” into its main components
The BMS is always in the car.
For AC charging (“Type 2 connector”), the power electronics are in the car, and the power connection is a glorified power socket. The limit is the lower of
For DC charging (the unnecessarily clunky “CCS connector”; or CHAdeMO for some Japenese cars), the power electronics are in the charging installation. The power connection will always operate on 230V 3 Phase, but at massive currents compared to the typical DC charger. These days 50kW are common, 150kW less so and 300kW are rare. Again there is a limit on what the car can actually use, the peak power capability is really only available from 30-70 percent state of charge.
Funny thing. In a matter of a month or two, Tesla superchargers have popped up literally everywhere. They used to be some 200 km apart and only usable for Tesla. Now in the Tesla app, I count at least 20 stations within 100 km from my home, each with 6-20 chargers. Kind of extreme actually. I predict all other charger companies bankrupt within a year, because Tesla is both the cheapest and the simplest. You need a phone though.
Peter wrote:
I dont know how (or whether) a charger measures the house draw and scales down its output limit based on that; obviously it is possible, but do they?
The bog-standard home wallbox doesn’t do that, but there are models with load management available. You can also get models intended for solar installation which can measure overproduction and direct that into a car, they also offer load management.
All devices with load management (solar or otherwise) have a power clamp to measure overall household power import/export.
More recent units are capable of being controlled by the power network to manage overall demand; I think this was made mandatory in the UK a couple of years ago, don’t know about the UK.
LeSving wrote:
Tesla superchargers have popped up literally everywhere. […]You need a phone though.
Or a Tesla
As anyone who had to faff about with apps (especially outside their home country) can testify, the “plug in and go” ability is priceless. My personal success rate actually using non-tesla chargers outside the UK is now below 50%.
Cobalt wrote:
My personal success rate actually using non-tesla chargers outside the UK is now below 50%.
My first time ever using a Tesla charger was on Sunday. It’s only recently they even allowed non Teslas on their chargers. This was in Sweden, and the first charger didn’t work. Tried a second one which worked flawlessly.
My success rate actually using a Tesla charger outside Norway is exactly 50% 
(my success rate inside Norway is of yet undetermined). My success rate on non-Tesla chargers is at least 95% (outside and inside Norway).
Perhaps wait until you have a larger sample size… mine is biased a bit towards France, the Netherlands and Germany. The main obstacle are not broken chargers, it is that payment is invariably via an app which seems to be different for each charger and sometimes written by somebody who does not understand that, perhaps, UK postcodes contain letters so you can’t provide it and you can’t provide a fake one because the credit card provider checks, ot a network that assumes you have a bank account in Germany or only accepts cards issued in Germany, or an app that simply “errors out”. Also even if you have the app already if you come back a couple of months later they seem to need an update before working.
Also many providers really want to sign you up with their own contactless chip, which you can order in advance. WIthin a country, you can get multi-company consolidators but they (a) are not free and (b) again seem to assume you live there.
It is really as idiotic as airport BP or other company specific fuel cards. If motorway fuel stations were as bad as EV chargers, the attendants would probably not survive more than a few hours.
