Effect of J1772 button while charging?

Hi there,
I did some searching and couldn't find an answer to this. I'm curious if my EVSE is working correctly.
When my LEAF is charging, and I press the button on my J1772 connector, it doesn't seem to do much of anything until I actually pull it out, and then I hear the relays close in the car. Should I notice anything just by pressing the button on the connector, or is this normal? My understanding is that the button should stop the charge, or at least show some sign of slowing the charge, but nothing seems to happen until I pull.
Mainly, I'm just wondering if I'm safely disconnecting while the car is charging.

When you press the button on the J1772 handle, It changes the proximity signal to the car. The spec says the car has to stop drawing current immediately so that there is not arcing when the plug is removed. Some cars will disconnect the EVSE when you press the button, but the LEAF only stops drawing power (the correct behavior IMHO). If you release the button without unplugging, the LEAF will continue charging after a few seconds. You can only tell anything is happening if you have a current meter on the circuit.

OK, so the lights on the dash don't change or anything? I haven't seen any arcing.

ishiyakazuo said:

OK, so the lights on the dash don't change or anything? I haven't seen any arcing.

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Correct. Nothing happens that can be observed except for the current going to zero.

Pressing the button causes the car to stop charging. According to the spec it should stop no later than 100MS. In any event long before you unplug the J1772 cable the car has stopped drawing current. The only time the EVSE opens under load is during an error condition like a GFCI error. Most of the time you are good. Tesla uses the 30A screened relay at 40A as per the spec sheet. At that current the stock 1/4 inch push on connectors are well beyond spec. Tesla used a arc welded cable according to the photos Ingineer released. In any event 40A is not trivial. 24A is easy.

GlennD said:

Pressing the button causes the car to stop charging. According to the spec it should stop no later than 100MS. In any event long before you unplug the J1772 cable the car has stopped drawing current.

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I get all that, but I was asking if there were any visible ways to verify that the button was actually having that effect, and it sounds like the answer to that is "not really." The original question is "how do I verify that my EVSE is doing its job and providing the correct signals to the car when I'm about to unplug it?"
I'm not really sure where the Tesla comments came in...
In any case, it sounds like I'll need to whip out the good old clamp ammeter if I want to check the behavior of the EVSE, but at this point, my mind has been put at ease.

ishiyakazuo said:

GlennD said:

Pressing the button causes the car to stop charging. According to the spec it should stop no later than 100MS. In any event long before you unplug the J1772 cable the car has stopped drawing current.

Click to expand...

I get all that, but I was asking if there were any visible ways to verify that the button was actually having that effect, and it sounds like the answer to that is "not really." The original question is "how do I verify that my EVSE is doing its job and providing the correct signals to the car when I'm about to unplug it?"
I'm not really sure where the Tesla comments came in...
In any case, it sounds like I'll need to whip out the good old clamp ammeter if I want to check the behavior of the EVSE, but at this point, my mind has been put at ease.

Click to expand...

You can't use a clamp meter on the cable to test amps as you can't isolate one wire inside the cable. If your car is not stopping when you push the release button adnd hold it for a bit you may have an issue with the internal micro switch.

That button does exactly one thing electrically; it adds 330 ohms resistance between ground and the proximity pin, which signals the car to stop charging within 100ms (1/10 of a second).

You should hear the contactors on both the car and maybe the EVSE open (some EVSEs have really quiet contactors).

Again, as far as your ears are concerned, when you press that button WHILE CHARGING, it should create an immediate click / clunk somewhere in the bowls of the car.

If not, there's a problem, and you may be pulling out the plug while under power. This can cause arcing / damage to the power pins, and a fire hazard.

The leaf is really confusing. It stops as per spec but the dash lights stay on. I had to measure the current to convince myself it had stopped.

TonyWilliams said:

...You should hear the contactors on both the car and maybe the EVSE open (some EVSEs have really quiet contactors).

Again, as far as your ears are concerned, when you press that button WHILE CHARGING, it should create an immediate click / clunk somewhere in the bowls of the car. ...

Click to expand...

Not on a LEAF. The LEAF stops drawing current but does not open any of the contactors. There are NO visible or audible signs that anything has happened. The only ways I could tell was that my meter went to zero, and my solar inverter stopped making the buzzing sound it made when it was generating and the LEAF was charging at the same time.

EVDRIVER said:

ishiyakazuo said:

GlennD said:

Pressing the button causes the car to stop charging. According to the spec it should stop no later than 100MS. In any event long before you unplug the J1772 cable the car has stopped drawing current.

Click to expand...

I get all that, but I was asking if there were any visible ways to verify that the button was actually having that effect, and it sounds like the answer to that is "not really." The original question is "how do I verify that my EVSE is doing its job and providing the correct signals to the car when I'm about to unplug it?"
I'm not really sure where the Tesla comments came in...
In any case, it sounds like I'll need to whip out the good old clamp ammeter if I want to check the behavior of the EVSE, but at this point, my mind has been put at ease.

Click to expand...

You can't use a clamp meter on the cable to test amps as you can't isolate one wire inside the cable. If your car is not stopping when you push the release button adnd hold it for a bit you may have an issue with the internal micro switch.

Click to expand...

You can use a clamp meter inside the EVSE by putting it around one of the wires... I didn't say I'd stick it around the J1772 cable

GlennD said:

The leaf is really confusing. It stops as per spec but the dash lights stay on. I had to measure the current to convince myself it had stopped.

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Ass GlennD says, its not always obvious. On my 2013 LEAF, if it is only charging, the charging stops the second I press the release button on the J1772 connector and all 3 charging lights go out. If only the climate control is working (preheating the car), pressing the release button has no effect and the charging lights remain on with one flashing. Of course the J1772 protocol says nothing about preheating and since that draws relatively little current its not a problem that that remains on even when pulling out the plug. It's clear, however, if it was delivering charing level current to the the car, that charging stops as soon as you press that button. So the proximity signal in the LEAF works as required even if its not always obvious that it does.

jpadc said:

GlennD said:

The leaf is really confusing. It stops as per spec but the dash lights stay on. I had to measure the current to convince myself it had stopped.

Click to expand...

Ass GlennD says, its not always obvious. On my 2013 LEAF, if it is only charging, the charging stops the second I press the release button on the J1772 connector and all 3 charging lights go out. If only the climate control is working (preheating the car), pressing the release button has no effect and the charging lights remain on with one flashing. Of course the J1772 protocol says nothing about preheating and since that draws relatively little current its not a problem that that remains on even when pulling out the plug. It's clear, however, if it was delivering charing level current to the the car, that charging stops as soon as you press that button. So the proximity signal in the LEAF works as required even if its not always obvious that it does.

Click to expand...

OK... the charging lights on mine don't go out when the J1772 connector's button is pressed, and I have never used the climate control timer (because I bought the car in March). I'll need to play with it some more, but I only hear the LEAF's contactors open after I pull the cable, which is what caused me to ask the question in the first place... maybe the 2013s' behavior is different (better)?

I was surprised when I first heard about this button, and I was skeptical. I had to resort to the "obvious ammeter", namely watching the garage lights dim! The wiring in this house is pretty solid, so it was fairly hard to see, but I could detect it. Don't look directly at the lights; if it's that subtle you can pick it up in your peripheral vision. Pushing the button causes the car to stop drawing current, and yes, there are no contactors opening when this is done.

I can also get other effects if I push the button. Results here may vary since I have timers in both the car and the EVSE. If I have the car plugged in, but the EVSE isn't ready, then hitting the button causes the CAN bus to wake up. You can hear a little relay click, and your GidMeter, LeafDD, WattsLeft, et. cetera will wake up for 5 seconds or so.

If the EVSE is live, but the car isn't charging because it's already charged, hitting the button causes charging to start up again, only to stop after 15 seconds or so, since it's already charged.

So, the button is connected, and the car knows when it's been pushed.

OK all, I proved to myself that my EVSE's button is doing the right thing using a much simpler method than all the other ones talked about (except for checking the lights dimming, but that seems like you've got another problem if that happens...)
My wife pressed the button as I watched the electric meter spinning. As soon as she pressed it, it slowed to a crawl (it was whipping around really fast while charging). Then I waited a moment (not pulling the cord) and the meter spun up again, she pressed the button again and it dropped back to a crawl. Definitely was having an effect, so I was content to know that it's indeed doing the right thing.
Thanks all for the various insights on this one!

ishiyakazuo said:

OK... the charging lights on mine don't go out when the J1772 connector's button is pressed, and I have never used the climate control timer (because I bought the car in March). I'll need to play with it some more, but I only hear the LEAF's contactors open after I pull the cable, which is what caused me to ask the question in the first place... maybe the 2013s' behavior is different (better)?

Click to expand...

On my 2014, the lights go out.

If the handle were defective, it might not be signaling. Perhaps try a few different stations?

alanlarson said:

ishiyakazuo said:

OK... the charging lights on mine don't go out when the J1772 connector's button is pressed, and I have never used the climate control timer (because I bought the car in March). I'll need to play with it some more, but I only hear the LEAF's contactors open after I pull the cable, which is what caused me to ask the question in the first place... maybe the 2013s' behavior is different (better)?

Click to expand...

On my 2014, the lights go out.

If the handle were defective, it might not be signaling. Perhaps try a few different stations?

Click to expand...

See my last post. Apparently the 2012s don't do anything, but they definitely draw zero or near-zero current (when the handle button is working, of course).

ishiyakazuo said:

alanlarson said:

ishiyakazuo said:

OK... the charging lights on mine don't go out when the J1772 connector's button is pressed, and I have never used the climate control timer (because I bought the car in March). I'll need to play with it some more, but I only hear the LEAF's contactors open after I pull the cable, which is what caused me to ask the question in the first place... maybe the 2013s' behavior is different (better)?

Click to expand...

On my 2014, the lights go out.

If the handle were defective, it might not be signaling. Perhaps try a few different stations?

Click to expand...

See my last post. Apparently the 2012s don't do anything, but they definitely draw zero or near-zero current (when the handle button is working, of course).

Click to expand...

I did my tests on my 2012 Leaf and the lights did not go off. I never retested my 2013. My B Class has no indication period but my OpenEVSE is fully metered. The B follows the rules.

I was going to go build me an OpenEVSE if my EVSE didn't do what it was supposed to, but it seems that it is, so I'll continue being lazy.