jray3
Posts: 1700
Joined: Tue Dec 06, 2011 1:05 am
Location: Tacoma area, WA
Contact: Website

Re: MCU 20A 450VDC fuse investigation

Thu Jun 04, 2020 2:57 pm

coulomb wrote:I was wrong when I initially thought the LEAF ignored the J1772 plug's push-button. It does indeed immediately and electronically (i.e. safely) ramp the charge current down to zero when the button is pressed. It's just that there is absolutely no indication that anything has changed; the blue LEDs stay the same, there is no beep or anything else to suggest that the current has stopped. As soon as you let go of the button, the current ramps back up to normal.


Hi Coulomb, I'm finding that the proximity switch does indeed do nothing on early LEAFs. On both of the 2011's that I've worked on with multiple EVSE, they never respond to the button push, and only break current when the shorter proximity pin comes out. Pull the plug very slowly, and you'll hear the EVSE contactor open up, but yank it fast, and there will be a little arc as you unplug. The i-MiEV responds quite nicely to the proximity switch.
2012 i-SE "MR BEAN" 110,300 miles
2016 KIA SOUL EV, 90 kW, 27 kWh, 34k miles
2000 Mazda Miata EV, 78 kW, 17 kWh
1983 Grumman Kurbwatt EV,170 kW, 32 kWh
1983 Mazda RX-7 EV 43 kW 10 kWh
1971 "Karmann Eclectric" EV 240 kW 19 kWh

coulomb
Posts: 198
Joined: Sun Jun 10, 2018 8:32 pm
Location: Brisbane, Australia

Re: MCU 20A 450VDC fuse investigation

Thu Jun 04, 2020 6:12 pm

jray3 wrote: On both of the 2011's that I've worked on with multiple EVSE, they never respond to the button push, and only break current when the shorter proximity pin comes out. Pull the plug very slowly, and you'll hear the EVSE contactor open up, but yank it fast, and there will be a little arc as you unplug. The i-MiEV responds quite nicely to the proximity switch.

The EVSE contactor coming off is different to ramping the charge current down to zero quickly. I actually prefer the Leaf's method which somehow doesn't cause the EVSE contactor to disconnect. It means I can use the button on my adjustable current EVSE to change the current; when changing to lower currents, I have to cycle all the way through 16 A, wrap back to 6 A, then continue up to the desired current. I prefer not to yank 16 A out of my home energy system unless the sun is really strong.

However, that doesn't explain the arc that you observe; maybe the behaviour is different between 2011 and 2012 Leaf models (they are otherwise very similar). Or maybe the fast yank doesn't allow enough time for the charge current to ramp all the way to zero before the AC power pins disconnect.

Can you test with the EVSE plugged in via a power meter, or use LeafSpy to check the charge current?

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