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Re: Cutting power to EVSE concerns

Posted: Sun Nov 03, 2019 5:24 pm
by LeftieBiker
I wonder if it detects the loss of pilot signal before the AC disconnects, and does a graceful disconnect anyway. I'd still way prefer that it heeded the proximity switch.
That is exactly what it does. The pilot pin disengages before the AC pin(s).

Re: Cutting power to EVSE concerns

Posted: Sun Nov 03, 2019 5:29 pm
by Todd1561
Yes my understanding is that is why the pilot pin is shorter than the charge connectors, so it’ll always disconnect before the main load. Similar to USB connectors.

Re: Cutting power to EVSE concerns

Posted: Sun Nov 03, 2019 10:02 pm
by davewill
The early LEAFs certainly DO heed the proximity pin. What they don't do is unnecessarily turn off the contactor in the EVSE. They instead simply kill the current draw, which is all that is required to prevent arcing. You can verify this with a current meter. When you press the button the current draw will drop to zero, and if you release the button, it will wait several seconds, then start drawing current again.

Go ahead and unplug with confidence.

Re: Cutting power to EVSE concerns

Posted: Sun Nov 03, 2019 11:15 pm
by coulomb
davewill wrote:
Sun Nov 03, 2019 10:02 pm
The early LEAFs certainly DO heed the proximity pin.
I'm very happy to be proved wrong in this case. I see in a video that with nothing plugged into the Leaf, there will be about 4.5V on the proximity pin to ground. Per the Wikipedia J1772 diagram, that has to come from a 5V supply, presumably in the On Board Charrger. So there must be a wire all the way to the OBC.

My wife has the Leaf right now (I should get one of those T-shirts that says "I love it when my wife lets me drive my Leaf"). But it will be great to see it actually happen.

Re: Cutting power to EVSE concerns

Posted: Tue Nov 05, 2019 1:33 am
by coulomb
I've seen it for myself now: the 2012 Leaf does indeed heed the proximity switch, and reduces the charge current to zero, as it should.

It just does it in such a way that you'd not notice it, which is actually pleasing in a way.

I was wrong: hooray! :roll:

Re: Cutting power to EVSE concerns

Posted: Tue Nov 05, 2019 6:07 am
by nlspace
coulomb wrote:
Sun Nov 03, 2019 11:15 pm
... with nothing plugged into the Leaf, there will be about 4.5V on the proximity pin to ground... that has to come from a 5V supply, presumably in the On Board Charrger. So there must be a wire all the way to the OBC.
There is a black wire pair, it can be seen in the AC connectors picture on page 1 of the OBC peek under the covers thread,
Image

skip past a bunch of blather to page 13 to find an inside view with the cover off,
Image

The black wire pair runs to the top board on the right hand side edge connector, pins 1 and 2. There is another connector below it with a black dot with a red wire pair on pins 3 and 4 that runs to the HVDC connector to the pack. You can see the red wire pair in the DC output connector.

i don't hear the Blinnk L2 EV_SE contactors, nor the car's main contactors snap off, when pulling the trigger. There is a small AC relay in a potted doghouse on the bottom board of the OBC which you could never hear--maybe that is being used to break the AC connection?

What could possibly be the benefit or reason to leave the contactors in the EV_SE and the car unnecessarily energized after getting the trigger release signal?

But i'm glad to hear that the current gets commanded to zero.

Re: Cutting power to EVSE concerns

Posted: Tue Nov 05, 2019 10:30 am
by davewill
nlspace wrote:
Tue Nov 05, 2019 6:07 am
...
i don't hear the Blinnk L2 EV_SE contactors, nor the car's main contactors snap off, when pulling the trigger. There is a small AC relay in a potted doghouse on the bottom board of the OBC which you could never hear--maybe that is being used to break the AC connection?
I'm quite sure the AC connection is not interrupted by the button. It's not necessary for it to be. That would only happen when the plug is removed and the pilot signal gets disconnected. When the button is pressed the charger just has to stop supplying current to the battery.
nlspace wrote:
Tue Nov 05, 2019 6:07 am
...
What could possibly be the benefit or reason to leave the contactors in the EV_SE and the car unnecessarily energized after getting the trigger release signal?

But i'm glad to hear that the current gets commanded to zero.
I doubt this was the intention, but it DOES mean that someone randomly pushing the button doesn't end your charge session at a commercial station. :)