30/04/09
EV Charging connectors
Recent History
The PSA EVs and others of the 90s generation used the "Avcon" style connector at the vehicle, with the other end usually terminated with the typical blue industrial connector.
The European version of the Avcon is rated for only 14A AC, single phase 230V (around 3kW). It relied on its high-current DC contacts for faster charging, using dedicated charge stations. It is also fairly complicated and takes a lot of space on the vehicle, and was incredibly expensive!
Marechal/Avcon, IEC 60309-2 230V/16A and 63A connectors, and a 16A to British 13A plug adaptor cable.
The near future
The new generation of EVs will have larger capacity batteries, so whilst a 3kW charge rate might still be adequate for overnight charging, a faster charge would be very welcome. The DC charging station idea wasn't very successful or widespread, as it was so expensive to provide. So, a higher current AC connector is needed, everyone agrees.
Wouldn't it be nice if all electric cars would have the same, standardised connector? Yes. And we're lucky, only two are currently proposed!
SAE J1772
The first is SAE J1772. This standard originally specified the Avcon connector. That has recently been re-worked to use a more sensible 5 conductor round-pin plug, which does not contain DC contacts.
As shown, the "Yazaki" connector has two pins for AC current, required to be capable of 70A. This would suit North America, where split-phase 240V is the common supply. More can be read about the connector here.
BUT! In Europe, it's far more common to have 3-phase supplies, often of a lower current but giving a similar or higher charge power overall. So, such a connector would be a big step backwards from the existing red (3 phase) IEC 60309 outlets which are already available.
IEC 62196
Therefore, Europe has recently come up with an alternative. Why not just use the existing IEC 60309? Well, there are a few drawbacks - the higher current versions are rather bulky and there's no provision for a pilot or data pin (to allow the cable to be de-energised when not plugged into a vehicle). As well, it would be an advantage to offer various different supplies such as 1 or 3 phase, and different current levels all through the same connector. This wouldn't be legal with the IEC60309 standard, and there are many existing devices using those connectors which expect the correct supply to be present at every socket.
The new connector is made by Mennekes. This was developed with requirements from RWE and Daimler, and was revealed only recently (a press release is on the RWE Mobility website). The connectors will be referenced under the IEC 62196 electric vehicle charging standard.
It looks pretty similar to the SAE connector - but it has 7 contacts in total, 3 AC phases and Neutral, with a 63A rating - giving an amazing 43kW maximum charge rate. If the car had a charger capable of using the full current (perhaps using the AC motor controller "in reverse"), this could be worth up to 200 miles of charge per hour!
It appears very compact for the power, compared to the IEC60309 type, and is not overcomplicated. The developers explain that the same connector could be used on both ends of the charging cable, and there is a locking mechanism to make charging secure.
But these connectors clearly overlap in purpose, so why not settle on just one? The European developers apparently have this in mind, since it's also possible to use the pins of the IEC connector for the USA single-phase application, but not the other way around..
Will the USA adopt it, or will "not invented here" syndrome be the deciding factor? We will find out soon!