EV charging

As an aside, I think that the introduction of 13A rectangular pin plugs in the 1950s was a retrograde step. The previous 15A round-pin plug provided a much more robust connection, with a cylindrical pin being a snug fit in a cylindrical socket. I'm aware that this was unfused, and it was deemed necessary to have fused plugs and also shutters - but surely that could have been achieved with round-pin plugs?! They could have had a different pin spacing to prevent the wrong combination of plug and socket from being mated.

Use a granny charger that can go down to 6A, and charge overnight.

And use such a granny charger that has a temperature-sensing plug. YKIMS.

'Which in our case, we have not got.'

(Apologies to Henry Reed)

Fine, unless you actually want your car to charge up overnight. 6 amp charging will be s….l….o….w!

Tim

when the 13A system was devised, there were at least 2 other competitors for the standard that used round pins.

And how fast could you charge with a hard-wired charger ?

Everything would be hardwired, except the thingy that goes into the side of the car.

Some of the cords on chargers, have been liquid cooled.

Paul

An interesting critique. Out of curiosity, would you say (in Germany) that a Schuko plug on a radial circuit fused at 32 amps would also be inadequate or is this a particular criticism of the ring main system?

Would Joe Bloggs know the difference between one that does, or doesn't?

On Fri, 6 Feb 2026 22:24:52 +0000, Roger Mills snipped-for-privacy@gmail.com wrote: [snip]

On Sat, 07 Feb 26 09:30:02 UTC, Charles Hope snipped-for-privacy@candehope.me.uk>

wrote: [snip]

Would this be Wylex and Dormer & Smith:

D&S has an interesting design that uses the fuse as one of the pins. The problem I believe was that the fuse could work loose and remain sticking out of the socket.

The granny charging cable is supposed to go into a box style outlet on the side of the dwelling, instead of on the end of an extension cable. The charger blob with the status LEDs, on purpose has a pretty short cable intended to allow the blob to hang down, just below the outlet.

People notice the warmth, but nobody is getting a skin burn right after unplugging. If any of the metal was at 65C, you would not be able to hold onto it for long. I replaced an outlet on the outside of my house, when an unplugged item showed itself to be "too toasty". That's where the corded electric lawn mower plugs in.

In my sampling then, two of three items for purchase, raise questions. That suggests to me, when shopping for these, you'd have to review the practicality of what they propose.

And for the price of that last item, you're "half way to a proper install". You might as well hard wire a box to the wall to do the charging. And if need be, have a separate circuit for it. If you want 240V at 40A, then use a proper installation for something that big.

If you're "visiting" anywhere, you cannot expect just the right kind of circuit to be sitting there. Maybe it's a house where nobody has considered the state of the electricals, for decades. The house back home, doesn't even have *safety ground*. It's grandfathered, and from before three prong plugs. How the hell do you charge at a place like that, when the equipment is on the prowl for "bad grounding".

And consider your ambient. If you have an abnormally hot summer day, that could drive the granny charger connector to a high enough temperature to have it disconnect itself. That is less likely to happen this time of year. In one comment here, someone chops the house end of their granny charger off, and now wants to know how to bodge in some thermistors to keep the temperature detection happy :-)

A home charger? Realistically 7 kW if you’re on single phase, up to 22kW if you have a three phase supply (relatively uncommon here) but that presupposes that your car can charge at the speed on AC. Few can.

Only on very fast DC chargers. Nobody householder will have the pockets or grid connection for one of those.

Tim

I fail to see why a DC charger is in any way superior to an AC one.Particularly since at all times there have to be electronics between the charger and the battery to prevent dangerous over charging.

A bridge rectifier and a capacitor is all it takes to turn AC into DC

I don't think it's a safety issue. I believe the traction battery can accept a much higher charge rate from DC. Maybe it's to do with the rectifier.

'DC' and 'AC' are shorthand for different setups.

'AC' means using the car's onboard SMPSU to generate the correct DC voltage and current to charge the battery. It's not a simple rectifier, it's an adjustable voltage/current SMPSU. You need to limit the current and adjust the voltage as the state of charge increases to maintain it. It's like plugging in your phone into 5V USB and using the internal charging circuit to generate the right DC output. The onboard charger is roughly the size of a shoebox and often lives under the bonnet, frequently combined with the motor inverter. It's typically liquid cooled via the car's radiator.

'DC' is basically a direct connection to the car's battery. The SMPSU sits in a phone-box sized cabinet somewhere nearby, often shared between several charging stalls. Because this can be much bigger (and better cooled, etc) you can achieve much higher charging currents than you can from the onboard charger.

In both cases a whole lot of software monitors the charging, state of charge, currents, temperatures, etc, in order to achieve a safe charge with minimum wear on the battery.

Yes, but that's irrelevant to how chargers work.

Theo

What people talk of as a home "charger" is not a charger at all, it should be known as an EVSE or CCID. It's basically a mains relay with some minor smarts to control it. However being a stickler about this is like correcting people over calling an Ethernet cable "RJ45" instead of "8P8C".

With home charging, the actual charger is within the car, and as you say it converts the AC to DC at a suitable voltage for the car's battery.

Some public charge points are AC only, so no better (or not much better) than a home charger, but "proper" public chargers will be DC, and they connect directly to the car's battery, bypassing the car's internal charger, there's more smarts here, because you don't want the external charger giving 960V to a battery that only wants 200V or 400V.

All the gubbins turned-up apart from the cable glands I'd ordered from eBay (seller says dispatched, EVRI still says waiting to receive parcel) so I can't neatly route the commando lead through the garage door frame yet.

New Type A, C Curve, dual-pole, 40A RCBO fitted in spare way of consumer unit, after a long game of "hunt the ferrules".

New interlocked commando socket installed in garage, audi EVSE plugged in by commando, charging cable now reaches car.

Car seems to be annoyed if I turn off power at the commando mid-charge, leaves the plug mechanically locked into the charge port, RTFM required.

Car has settings for 8A, 16A or MAX

EVSE has setting for 50% or 100%, which varies depending whether it has the 13A plug lead or 32A commando lead connected.

But after a couple of attempts, it's now sucking 30A according to my clamp meter.

For a "portable" EVSE I don't think PEN fault protection is expected, but given this setup isn't ever going to move, I think I'll end-up converting the commando socket from PME to TT earthing ...

my car (and SWMBO's) need me to operate the door unlock to release the charge cable.

Ah. I assumed this was still 'home charging'

Well no, in this case it isn't

The 'DC charger' is simply a bigger off board AC input SMPSU with a bigger rectifier and capacitors.

The difference being the car seems not to have to carry the weight of it around...