Bad news using my retrofitted EVSE with the LEAF :(

[garygid]

The J1772-2010 Standard seems to require a switch in the "nozzle" as part of a "proper" Proximity circuit implementation.

Measure the Resistance of the nozzle's Proximity pin to the ground pin. It should be about 150 ohms normally, and about 480 (150 + 330) ohms while the "Release" lever is pressed.

The internal switch shorts across a 330 ohm resistor that is wired in series with a 150 ohm resistor.

 

[LEAFer]

How about trial-by-error on this one ... and I would check both the AV (L2) and the portable L1: while your LEAF is actively charging (sipping juice) ... without removing the J-plug from the charge port ... just push the button on the plug. What happens ?

 

[Spies]

But you are forgetting that this particular thread is about MIXING the OLD technology J1772-1996 (MCS unit) for use with the NEW standard (J1772-2010). The mixture, IMHO, requires more caution.

I may be wrong about this but I am only aware of two J1772 standards being J1772-2001 and J1772-2010 and my EVSE follows the former. Of course your point is still just as valid

Nice little history on the subject http://evauthority.com/a-short-history-of-electric-vehicles-and-charging-technology/

Link to purchase the SAE J1772 Recommended Practice documents http://standards.sae.org/j1772_201001/

 

[LEAFer]

Of course I have no way of knowing which version of the standard your EVSE follows ... I semi-purposely quoted "1996" to draw a bigger distinction between OLD and NEW and 2001 and 2010 could cause misinterpretation for dyslexically challenged readers :lol: (just kidding on that last part).

The 2001 replaced an OCT1996 version. See here: http://bzwxw.com/soft/UploadSoft/new5/SAE--J1772-2001.pdf (upper right corner)

Oh ... and look on page 11/32, section 5.4 ( I have not taken time to read the whole doc ... remember it's the 2001 version. )

 

[Spies]

Of course I have no way of knowing which version of the standard your EVSE follows ... I semi-purposely quoted "1996" to draw a bigger distinction between OLD and NEW and 2001 and 2010 could cause misinterpretation for dyslexically challenged readers :lol: (just kidding on that last part).

The 2001 replaced an OCT1996 version. See here: http://bzwxw.com/soft/UploadSoft/new5/SAE--J1772-2001.pdf (upper right corner)

Oh ... and look on page 11/32, section 5.4 ( I have not taken time to read the whole doc ... remember it's the 2001 version. )

And there is Gary's circuit on page 8, section 5.1 Nice find by the way.

Well I made the simple circuit and hooked it up to the EVSE and, drum roll please, it worked exactly as expected. So there is still a mystery to me as to what is going on behind the scenes between the EVSE and the LEAF. Hopefully the folks at Clipper Creek will know exactly what is happening otherwise I suspect I am going to need a copy of the J1772-2010 spec and an oscilloscope to even begin to figure this out.

One thing I did happen to notice is that when a timer is set on the LEAF and I plug the connecter into the LEAF while the EVSE has power and the LEAF goes through that cycle that triggers the EVSE to close the relays and then open them again the LEAF no longer thinks the EVSE is connected. The LEAF does show its plugged in however. I have also noticed that the LEAF will be in that same state after a successful charge in that the LEAF shows that it is no longer connected to the EVSE but still plugged in.

 

[Spies]

The J1772-2010 Standard seems to require a switch in the "nozzle" as part of a "proper" Proximity circuit implementation.

Measure the Resistance of the nozzle's Proximity pin to the ground pin. It should be about 150 ohms normally, and about 480 (150 + 330) ohms while the "Release" lever is pressed.

The internal switch shorts across a 330 ohm resistor that is wired in series with a 150 ohm resistor.

Gary you nailed it again! I just went out and measured the Yazaki plug and I got 149 ohms and with the release held down 479 ohms. No idea what the LEAF does with that but I did not notice anything by engaging and disengaging the switch when plugged into the LEAF.

 

[AndyH]

Guys, the J1772-2010 doc is linked in the reference docs section of the forum. http://wenku.baidu.com/view/10b7d51755270722192ef7b6.html

As has already been addressed in various posts, J1772-2010 already has something like triple redundancy with regard to safely pulling the plug from the car - the pins are staggered so the control circuit is cut first (and this must kill power within milliseconds), pushing the 'release' button on the handle must kill power within milliseconds, pushing stop on the EVSE must...you guessed it - kill power within milliseconds. Good luck trying to get this plug to arc on insertion or removal!

 

[garygid]

Car thinking it is plugged in is the Proximity pin, no connection back to the EVSE.

Car thinking that the EVSE is no longer there is either the PWM Control Pilot goes away (or the +12v DC Control Pilot pre-connection voltage goes away too), so the car thinks that the EVSE is no longer present. A DC voltmeter measurement of the CP line should tell us what is happening.

 

[Spies]

A DC voltmeter measurement of the CP line should tell us what is happening.

Tell me how and I am on it! I have a volt meter at my disposal right now

 

[garygid]

Can you access the Control Pilot wire in your EVSE (that enters the e-hose)?

And the Ground?

Does the voltmeter have a 20v DC setting?

Can you do this without injuring or killing yourself?

 

[Spies]

Can you access the Control Pilot wire in your EVSE (that enters the e-hose)?

And the Ground?

Does the voltmeter have a 20v DC setting?

Can you do this without injuring or killing yourself?

Yes, yes, yes and yes.

"Help me, Obi-Wan Gary. You're my only hope."

 

[garygid]

OK, attach the voltmeter, do the connect to car, etc. (or my test sequence) and record the DC voltage readings. Do the same test sequence taking AC voltage readings.

It "should" start and end with +12 volts DC, and 0v AV, before connecting to the car, ... but post your results:

Test step description, DC volts, AC volts.

What "Max Current" is your EVSE supposed to deliver?

 

[Spies]

OK, here we go, reading from pilot to ground with the volt meter and the pilot connected to the test circuit.

11.80 DC, 0 AC test circuit open
-0.76 DC, 11.03 AC test circuit connected with 2.74k resistor
-2.31 DC, 9.43 AC test circuit connected with 2.74k and 1.3k resistors (relays engaged)
8.77 DC, 0 AC test circuit connected with 2.74k resistor after 1.3k resistor removed (relays disengaged)
11.80 DC, 0 AC test circuit open

So the pilot behavior is certainly different once the relays are closed and opened the first time. I cycled the relays a couple of times by adding and removing the 1.3k resistor and the readings did not change back to the first reading until I removed the test circuit and added it back again. So what does it mean?

Max current from the EVSE should be 32 amps and the EVSE itself is rated for 40 amps.

 

[garygid]

The 8.7 DC, 0 AC would seem to indicate that your EVSE stopped generating the PWM signal (and went back to just a "+12v" output) when the 1.3K was removed (indicating "finished charging).

I believe that the LEAF expects the PWM to keep going in that "Power Off" state, as an indication that the EVSE is still willing to provide power. However, your EVSE turns the PWM off (and keeps it off), indicating to the EV that the EVSE is no longer willing to supply power to the car.

The J1772-2010 standards inducate that the PWM should keep going, but allowing the PWM to stop also appears to be permitted. However, the no-PWM indicates that the EVSE is no longer willing to "play" with the car.

So, it appears like (from this distance) the LEAF is properly expecting the PWM to continue, and is actually in spec with J1772-2010, but ... I cannot be absolutely sure.

You are located in Foster City?
Where is that?
Oh, between San Francisco and San Jose.
A bit far for me to visit.

One could do the same test on somebody's AV (or other 30-amp EVSE) to verify the "different" operation.

However, that does not solve your problem, or make the LEAF's Timer-Mode charging work as expected with EVSEs that behave like yours apparently does.

Edited to say EVSE appears to be out-of-spec for multiple-current-draw uses.

 

[Spies]

You are located in Foster City?
Where is that?

San Francisco Peninsula and according to Google about 414 miles from you
What did you have in mind?

 

[garygid]

Coming to help, but ... I added an Edit above.

 

[Spies]

One could do the same test on somebody's AV (or other 30-amp EVSE) to verify the "different" operation.

However, that does not solve your problem, or make the LEAF work as expected with EVSEs that behave like yours apparently does.

Oh, I see you updated your post. I wonder if the guys over at Boardwalk would let me abuse their EVSE

Hopefully the Clipper Creek folks will be able to shed some light on this subject when I try to get a hold of them tomorrow.

Thanks again for all your help Gary.

 

[garygid]

Although it MIGHT be that the LEAF "expects too much" of your EVSE, it actually appears that your EVSE was designed for "single-charge" type of use. However, your EVSE might only need a firmware change.

Also, the old J1772 standard COULD have been different, and your older EVSE MIGHT have been OK for the older standard, but I do not know.

Of course, I could be wrong, and something else entirely might be the problem. Like, the "EV" in our test did not draw any power, so peehaps your EVSE stops the PWM because of that ... or something else again.

However, it really appears that the LEAF is in "spec".

I am willing to discuss/describe the technical issue to somebody who wants to help you.

EDITED: LEAF appears to be in spec, but this particular older EVSE appears to only work for "single-charge" charging sessions.

 

[garygid]

Sent you a PM.

 

[AndyH]

Gary - remember when I suggested that the pilot signal had changed from 'then' to 'now'? I'm having "Hunt for Red October" flashbacks: "He's just an analyst!" :lol:

No - the Leaf is not out of spec. It's in spec with the J1772-2010 that it was designed around. It's going to take more than a cable to upgrade older EVSE.

EVDRIVER - Thoughts?