Cars (all fuels and electric)

I am pretty sure there are EVs which can plug into a 13A UK socket… little ones?

Not directly, it needs a little box in the cable which tells the car what it is connected to. Some have a fixed plug and fixed max power, some boxes have an exchangeable connector on the power side you can swap out (UK, various European ones, “commando connector” and the box adjusts power depending on which one is installed), some have a way to set the power by using an app or buttons.

The in-line box does the same as the wallbox, but strangely enough cost far less (you can get these cables for less than 100 pounds/euros on aliexpress, or 150 at auto retailers)

Right – that must be what I meant by “direct plug in”

Peter wrote:

~3 people in an average street buy a Tesla, and fit the max-capability charger (which then was ~50kW, which btw needs 3 phase anyway) then the street-end transformer will be at full capacity.

The thing is for charging at home, I doubt anyone’s doing max capacity. The needs of charging at home are generally a slow charge over a very long period, you only generally need fast charging for en-route charging, or where you can’t wait. 99.9999% times charging at home, it will be at least overnight.

johnh wrote:

wow! That’s nearly 2000A at 220V. Are there really 350KW chargers out there?

Just for fun, I checked my hometown (Uppsala) using an app that lists charging stations. I found 22 stations with 350 kW or more – a few could do 400 kW. I guess these are primarily intended for lorries.

Cobalt wrote:

An EV cannot connect to a simple 3 phase connector (or a simple 1-phase wall plug) because the “glorification” is missing. At a minimum the wall box or the “granny charger” coming with the car needs to be able to tell the car how much current it can deliver. Not a complicated or expensive thing but without it (via the data lines in the connector) the car won’t charge.

Tesla sells an adaptor to connect to a 16A or 32A single phase wall plug

Mercedes sells an adaptor to connect to 32A three phase and one to connect to 16A three phase, and one to connect to 32A single phase and one for 16A single phase

lionel wrote:

esla sells an adaptor to connect to a 16A or 32A single phase wall plug

Yes – AKA as “the granny charger”.

The whole stuff is quite primitive.

The “Type 2” connector has two pins for the purpose of controlling the charging process, PP and CP

• PP tells the car what the cable can handle. It is a simple resistor between the PP pin and the earth wire. 220 ohms means 32A, 1,500 ohms means 13A, for example. This is built into the cable

• CP is a two-way communications protocol of some sorts. The charge point (granny charger/wall box/whatever) pulls this pin up to 12V via a 1 kiloohm resistor using a 1 kHz sqiuare wave with pulse-width modulation – 0.6 ampere for every 10 microsecond pulse width. So for example 530 microseconds on, 470 microseconds off pulses indicate 32A capacity. The car pulls the voltage down to 9 volts when plugged so the charger knows when a car is connected, and to 6 volts to start charging. When the car no longer wants to charge, it allows the voltage back to 9 volts.

Not really that complicated, but if the car does not see the 12V PWM signal it won’t charge.

Cobalt wrote:

Yes – AKA as “the granny charger”.

The whole stuff is quite primitive.

(…) if the car does not see the 12V PWM signal it won’t charge.

What you seem to say is that the adapter/cable implements CP and presents CP to the cable, without the “female connector on the wall” (IEC 60309) being anything more than a purely mechanical passive electrical connection to the mains. The end result is one can, through the adapter/cable, “connect an EV to a simple 3 phase connector that does not have any glorification”. One can drive up to any place that has an IEC 60309 connection to the mains, plug in and charge the car. No fixed installation needed at the place one wants to charge.

Just like I can charge my NiMH AAA batteries or 18650 Lithium batteries from the mains without having any fixed apparatus installed at every place I want to charge them. Same with my pocket computer, tablet, laptop, wireless headphone, etc. All these things do not directly expose the battery to the mains 230V AC, that is not the discussion.

Peter wrote:

I’d like to see how they worked that out, since there is obviously almost no supporting data

There is a lot of supporting data. This 800,000 km number was heard in a conversation (so I don’t have a source for it) but this shows that most EV batteries will outlast their useful use (at least for professional operators). Many factors of course influence the degradation, but overall :

• the average capacity degradation is 2.3% per year (1.6% under ideal temperatures), and is not very significantly dependent on the amount of miles driven
• a battery will retain 70% capacity for 15 years

Cobalt wrote:

My personal success rate actually using non-tesla chargers outside the UK is now below 50%.

This is starting to look like VFR dispatch rates, which is fitting :)