Odd Symptoms L2 Charging from Generator

[bobkart]

The generator is this one: https://www.amazon.com/gp/product/B00NXYLUM2 . . . it's rated at 7.2kW continuous. The L2 EVSE is the ClipperCreek LCS-25P . . . it should draw ~5kW at most. I used an adapter from the generator's L14-30 outlet to the 14-50 needed by the EVSE. I confirmed 'straight through' continuity for all four conductors of the adapter. I also used a ground-neutral bond plug as previous tests with the OEM L1 EVSE confirmed the need for this.

The charge session started normally, but checking the dashboard showed only 3kW instead of 6kW as I get with this same EVSE when plugged into the wall. Then after about five minutes the charge session ended. Power light on the EVSE was still on. At first I though I had broken the onboard charger, but both the OEM L1 EVSE and the LCS-25P still worked from the wall. So I tried again with the generator, and got the same shutoff after about five minutes. This time I noticed that the green 'plug' light on the dash was still lit (but not flashing), so the Leaf knows there's an EVSE connected. I *never* use the charge timer, but I hit the Charge Timer Off button and charging started again. It also seemed to work to unplug and replug the J1772 connector. I confirmed that the charge timer is OFF, but got this same five-minute shutoff on several retries. Hitting the Charge Timer Off button consistently restarted charging.

My best theory so far is that the generator output is drifting outside of some acceptable range and that's causing termination of the charge session. Not sure if it's the EVSE or the onboard charger making that call. Also not understanding why the five-minute part is so consistent; if it's just due to 'random' generator output variations, I'd expect less consistency in that number.

The 3kW-versus-6kW symptom suggests that the voltage is low, but ClipperCreek recently confirmed that this EVSE will check that there's at least 185VAC on it's input, when I asked them if I could use in with 120VAC input. Measuring that voltage would be a likely next step for me . . . maybe it sagging too low is what's terminating the charge sessions, and being low at all is what's making the Leaf think it's being charged at only L1 voltage levels.

Any ideas/advice/suggestions welcome . . . this is just for use in power-outage situations, so not too concerned about getting this working more flawlessly.

 

[nlspace]

Do you have any datasheet or measurements which show that it can actually deliver 7200 Watts from the 4-wire outlet?

The outlet is rated for 120-240vac 30A, but it is generally not intended to operate at that level, but more likely 80% of the current rating especially if the circuit breaker is only rated 30A. In which case you are looking at about 5600W, which is insufficient for the 6.6kW chargger.

The 5 minute shutoff may be related to the surge rating available for the limited time (spec'd in datasheet?) and the heat in the windings causing increased resistance and lower current available.

My guess is that the sales and marketing dept has misrepresented the performance of this device.

 

[bobkart]

Thanks for your help, nlspace.

I found the owner's manual and it claims 30A/240VAC on that outlet (7.2kW) on the specifications page. The EVSE will pull 20A/240VAC at most (4.8kW). So that's only 2/3 of what the outlet is claimed to support (well under 80%).

I understand that this may be a problem of trying to draw more than the generator can *realistically* provide. A couple of things push me away from that theory though: I hear *no* obvious signs of load on the engine. Granted I had hearing protectors on so I may have missed it. But with previous generators I've owned, and occasionally even with this one, I can hear the engine load increase when I add a large enough electrical load.

Second clue is that pressing Charge Timer Off (right after a charge sessions terminates) will resume charging, and I get another (about) five minutes before that terminates. If this was a load-induced-temperature-related shutoff, I wouldn't expect things to cool off quickly enough to allow that, i.e. a second immediate charging attempt would terminate much more quickly.

Additionally, the power light on the EVSE remains lit when the charge session terminates, leading me to suspect it was the Leaf's idea to terminate the charge session, not the EVSE's (or the generator's).

 

[nlspace]

It could be that the car is detecting a condition with which it is not happy.

The AC goes thru a EMI filter before entering the OBC, then a small fuse and emi filter section inside before going to a rectifier section. The output of that is fed into a PFC (power factor correction) section that reads the AC voltage and current, and switches some transistors to try to get the voltage and current in phase.

It may be that the generator phasing is offset that is causing an issue with the PFC section and the OBC is shutting down. Do you have leafspy app, maybe an OBC DTC is being set? The factory service manual has quite extensive troubleshooting for some of the codes, so any listing of codes would help.

 

[bobkart]

I'm about to get an end-of-day LeafSpy snapshot (for my spreadsheet) . . . I'll check for DTCs too and report back here later tonight.

While I have you (since you seem quite knowledgeable about Leaf charging), I've been wondering about L1/L2 charging with DC as opposed to AC. Here Ingineer suggests that it's possible:

https://www.mynissanleaf.com/viewtopic.php?f=26&t=5792&p=133611#p133611

Motivation would be to charge from batteries (say, 96VDC nominal) and avoid the inverter costs and losses.

Thanks again for your help.

 

[bobkart]

That last one (B29A0) looks like it could be relevant.

I think most/all of the others are because I had the 12V battery out a couple of days ago.

 

[nlspace]

i only have the 2012 FSM, and VC-95 has a procedure for the measurement of the insulation resistance of the OBC HV output terminals 31 and 32 to ground, should be >20Meg with 500V applied for 30 seconds (megger tester).

The B29A0 has 2 parts related to the EVSE connection detection circuit signal voltage levels out of range, either stuck too high or at an invalid voltage range. Dirty connection terminals or release switch, bad circuit power supply, bad ground of power supply, resistance between charge point terminals (should be 2.43-2.97 k).

 

[bobkart]

Thanks again for your help, nlspace. Between when that problem happened and now I've done the following:

- cleared all DTCs
- L1 charged with the OEM EVSE multiple times, for hours at a time
- L2 charged with the same EVSE that's involved in the problem (from the wall, not the generator), for long enough to confirm that it doesn't cause the problem
- L3 charged once (for over 30 minutes)

(I know the last one uses a different charging port.)

I checked DTCs after all that and still nothing. This leads me to rule out problems with the J1772 charge port. Instead it feels like some combination of the generator output and the L2 EVSE in question are causing the Leaf to detect a problem (and thus terminate the charge session). The pilot signal drifting out of range is one likely cause, voltage sagging on the 240VAC lines could be another.

If I had other generators and/or other L2 EVSEs, I'd be trying them in different combinations to see what effect on the symptoms that has. But I only have this one combination. The next time I fire up the generator I'll try to measure the 240VAC output voltage, both unloaded and loaded (L2 charging).

One more potentially-related symptom has shown up: my LeafSpy battery health stats (Ahr, SOH, Hx) have all been stuck at the same numbers since the day *after* this happened. If it was on the same day I'd be more convinced of a cause/effect relation, but with the stats having moved after that day, and *then* freezing, I'm less sure. (Both LeafSpy Lite and Pro show the same frozen numbers.)

Maybe this is a topic for a separate thread, but has anyone had their battery health stats freeze like that? Everything else about the car seems fine.

 

[WetEV]

Maybe this is a topic for a separate thread, but has anyone had their battery health stats freeze like that? Everything else about the car seems fine.

Happens every winter. The battery stats don't update below some temperature.

 

[bobkart]

Happens every winter. The battery stats don't update below some temperature.

Ah, good to know . . . thanks.

I didn't start taking readings until June of this year. Surprisingly (to me anyway), the stats are higher now than then.

Sounds like I'm in for a surprise in March though.

 

[WetEV]

I didn't start taking readings until June of this year. Surprisingly (to me anyway), the stats are higher now than then.

Sounds like I'm in for a surprise in March though.

LeafSpy reads out the BMS's estimated battery condition. This estimate can vary. I've more than a +-3% variation, changing with temperature, different driving patterns and different charging patterns.

Batteries don't lose much capacity over the winter, usually.