broadgage:

It would have been better in my view for the charging circuit to be built into the vehicle, and only requiring the connection of a mains input. A simple mechanical keyway on the connection could "tell" the charger what supply was available. A choice of four supplies would meet almost all requirements.

This is essentially what we have for AC charging, only with a simple analogue control signal rather than a keyway, and a couple more options, add 1x16A and 3x16A* to your list, and replace 1x13A with 1x10A as that's what all the granny cables do. This system is fine and works, with a simple pilot signal that encodes 6-80 A available, and a couple of other checks like PE continuity and the ability to check the CCC of a user-supplied cable with a built in ID resistor.


For what it's worth there's no longer a mainstream car on the market that supports 3x63A AC charging, newer Renault Zoes have dropped it as an option in favour of DC. 3x32A is still common on many vehicles. I suspect the main issue is that American charging stations and cars with type 1 connectors don't support 3 phase at all so the market is more limited. I am inclined to agree with you that wider support for high power AC charging is desirable, simply because the charging stations are simple, low-complexity connectors not huge banks of power electronics. That makes them cheap to install which is clearly important for rollout.


DC charging is messier as the power conversion is handled off the vehicle and there's a completely different protocol to communicate between charger and car. It also means a given charging site needs a separate bank of power electronics per car if it is to charge more than one at once because they will each need a different voltage and current setting.


From a user perspective by far the biggest thing that needs fixing is payment, which has generally been a mess of supplier-specific accounts with phone apps or RFID cards. Contactless payment is slowly improving this. Failure to charge is commonly related to payment issues, with the charger or a smartphone failing to connect properly to some remote server.

RichardCS2:

3x22A is still common on many vehicles.

Is that a wee typo? 3 x 32 A = 22 kW?


I am a little surprised that it is commonplace, but EVs are not exactly my specialist subject. Having just bought a new (petrol) car, I shall not be rushing to buy an EV, although my next car may well be one.

Chris Pearson:

RichardCS2:

3x22A is still common on many vehicles.

Is that a wee typo? 3 x 32 A = 22 kW?


I am a little surprised that it is commonplace, but EVs are not exactly my specialist subject. Having just bought a new (petrol) car, I shall not be rushing to buy an EV, although my next car may well be one.

Well spotted, now fixed.


As I understand it 3x32A is common because it covers multiple markets - it allows single or split phase 7 kW charging (UK, USA) and 3 phase 11 kW charging (bits of Europe normally having low current three phase supplies) which are both common approaches in different parts of the world. Actual use at 22 kW is something of a bonus that drops out of that. There's at least one manufacturer who does it by having three 16A single phase chargers and using two for 7 kW single phase and three for 11 kW three phase, not giving a 22 kW mode.

broadgage:

It seems to me that the whole business of charging electric vehicles has been made over complicated, and therefore more costly and less reliable than one might hope for.

It would have been better in my view for the charging circuit to be built into the vehicle, and only requiring the connection of a mains input. A simple mechanical keyway on the connection could "tell" the charger what supply was available. A choice of four supplies would meet almost all requirements.

Single phase 13 amp

Single phase 32 amp

Three phase 32 amp

three phase 63 amp.


For trucks, buses and electric trains, perhaps add 125 amp at 690 volts.

But that doesn't allow for dynamic charging rates.  That could be a bank of roadside chargers, all fed off a single supply, or else a domestic charger sharing a 60A house supply with all the other appliances.  Type 2 charge points should be able to re-negotiate the power availability on-the-fly.

davezawadi (David Stone):

It seems that manufacturers of electric cars are STILL not on the same page. All this stuff about charge rates and supplies is not the big problem, and DC charging just throws another difference into the pile. Why have they got such incompetent system architects setting the charging methods? I only want class 2 cars, that is also too difficult apparently. It is not difficult to design a charging circuit that can accept any of these supplies, with high efficiency. It is not difficult for the car to communicate wirelessly with the charging point, or expensive. It could be Wi-Fi, Bluetooth, or a special protocol, most cars already have these connections. We just need a common 3 phase socket, connected to whatever is available, be it 440V 3 phase or 230V or 110V single-phase or whatever.


Your car then sends its serial number to the charging point, the driver checks the right reg. number is returned by the charger, the car negotiates the available supply, on a real-time basis if you like, and you are charged on your account. Simple enough, and fairly hack and foolproof. This is how networking and charging should work, a great pity that they don't! Existing cars can still be charged, they just need a protocol adapter lead which would be fairly cheap.


All new cars should also be class 2, which is also cheap to implement!

Wireless risks all sorts of problems when you have a row of chargers.  You could easily find that every car on a row of chargers is in range of every charger.  How do you ensure that the right driver gets billed for the right car?  The charging leads already in use have pilot wires, which can be used for a serial link.


Tesla have got it right, if you're using a Tesla car on a Tesla charger.  You plug in the car, it identifies itself to the charger, and you get billed automatically.


But we're now stuck with a legacy of many thousands of existing cars, as much as 10 years old.  We can't just scrap them all, because we want a new charging system.  So the manufacturers keep extending the existing charging system to incorporate faster charging, including DC charging, and hitting endless compatibility problems with the vehicles already on the road.