View Full Version : Electrical charging station standard

02 October 2010, 0752
I didn't know that there was a standard now for those electrical charging stations. Evidently they are all going to this standard. SAE J1772 was adopted on January 14, 2010 by the SAE Motor Vehicle Council. The companies participating in or supporting the revised -2009 standard include GM, Chrysler, Ford, Toyota, Honda, Nissan and Tesla.

Tony Coiro
02 October 2010, 0818
I'll second this, the EV Club we formed here at Purdue a week ago met with GE, who is installing 10 charge stations on campus. They are helping us integrate into their systems and this is the plug they are using.

02 October 2010, 1130
I recently saw prices on these plugs.... $200+ for the vehicle receptacle, or $700+ for the receptacle and a charging plug with cable. Who is making all the money on these? It's not like they're *that* much more complicated than a $15 220v cord for a dryer.

02 October 2010, 1211
I'm wondering if there are adapter plugs to use these charging stations on a regular 110V plug that most of our bikes already have?

02 October 2010, 1401
Here is one I found for $68.

I don't know if there is any commercially available adapter. I am sure someone will make one, but it would probably be cheaper to make an adapter yourself.

02 October 2010, 1602
Ok, I can't see how we can use these chargers even if we install an SAE J1772
connector on our bikes. How do we provide the charger the required protocol information for it to work?

02 October 2010, 2335
I wouldn't be too concerned about the protocol info because, as with most 'standards', the blurb is more confusing than the actual implementation.
Basically, the connector specified in the J1772 standard has 5 pins ...

Pin1 AC Power L1
Pin2 AC Power L2, N
Pin3 Ground
Pin 4 Control Pilot
Pin5 Proximity Detection

Pins 1,2 & 3 are self explanatory.

Pin 5 is used to detect that the connector is inserted and is generally used by the vehicle to implement some form of interlock to prevent being driven away and damaging the cable / connector etc. Not really necessary for an observant motorcyclist :) and doesn't need to be connected.

Pin4 The charging station puts out 12VDC over a 1K resistor to this pin and the vehicle connector shorts a diode and a 2K74 resistor across pins 4 & 3.
The 2K74 & diode pulls the 12V down and indicates to the station that a real vehicle is present, but does not yet require power.
The station then puts out a 1KHz +/-12V square wave on pin 4 and waits.
The vehicle then simply shorts (via a switch/relay/FET etc.) either a 1K3 or a 270R across the 2K74 resistor. This closes the station contactor and supplies power to the vehicle.
1K3 says no ventilation required, 270R says it is required.
This switch is effectively your charge relay. When you've finished charging, simply open this switch and the station contactor will open and cut power to the vehicle.

There are of course some other features that can be implemented, but the above is all that is actually 'needed'.
The main additional feature is that the Control Pilot (Pin4) is actually a pulse width modulated output, not a true square wave. The idea is that by altering the duty cycle of the output, the station can signal to the vehicle charger what the maximum current is that it is allowed to draw. The reality is that unless there are a number of related stations in use or the vehicle charger is demanding a huge current, then it can just be ignored.


03 October 2010, 0741
Wow, my head is going to explode with all of that information. Thanks for the info :)

03 October 2010, 1052
Here is one I found for $68.

I wish!
That $68 is just for a copy of the SAE standard (not sure if printed or download).


03 October 2010, 1255
Thanks Rob! Sounds like something we could easily implement with a simple micro.....:)

04 October 2010, 0609
Excellent info, Magicsmoke.

04 January 2011, 1045
Jack Pritchard's blog for January 1, 2010 has a schematic for setting up the circuit on the receptacle and in that episode of the show, he gives a thorough explanation of the set up. He also mentions that Tuscon EV (http://www.tucsonev.com) sells a receptacle pre-wired with the circuit ($170) they also list the receptacle alone for $100.


04 January 2011, 1056
Tucson EV (http://www.tucsonev.com/) maybe? ;)

This is the kind of thing I was looking for for my bike. A little too spendy this time around, but I might implement something like this on a future build.

Of course, we'll never get any charging stations in podunk Alaska, unless I do it myself. Hmmmm...... there's an idea.

04 January 2011, 1527
Here is some extra info on plug in sites near you:

Plug in sites (http://www.pluginolympia.com/plugins.htm)