Charging the Kona EV with a Generator?

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Toolworker

Toolworker

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I have a Honda EU2200i generator and seven gallons of two year old stabilized gas that I'd like to run through it and charge my Kona EV. It would avoid taking the gas to a toxics recycler (and incidentally provide a true MPG figure for a car that can't burn gas).

The problem is that the Hyundai charge cord shows a fault. Apparently the generator has a floating ground. I've tried connecting its ground terminal to a grounded water pipe and the ground pin of an outlet (both over a long extension cord) and several metal stakes up to 18" into the ground.

Has anyone made this work, with this or any other floating ground generator? Any suggestions?
 
Toolworker said:
I have a Honda EU2200i generator and seven gallons of two year old stabilized gas that I'd like to run through it and charge my Kona EV. It would avoid taking the gas to a toxics recycler (and incidentally provide a true MPG figure for a car that can't burn gas).

The problem is that the Hyundai charge cord shows a fault. Apparently the generator has a floating ground. I've tried connecting its ground terminal to a grounded water pipe and the ground pin of an outlet (both over a long extension cord) and several metal stakes up to 18" into the ground.

Has anyone made this work, with this or any other floating ground generator? Any suggestions?
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We used this (pretty much a necessary accessory to carry at the time with Leaf Gen1 range when new @80 miles) as there were limited public charging spots. Read the details provided in the related thread postings:)
https://mynissanleaf.com/viewtopic.php?f=26&t=5792#p133611
https://mynissanleaf.com/viewtopic.php?f=26&t=5792&start=30#p182547
 
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electriceddy said:
We used this (pretty much a necessary accessory to carry at the time with Leaf Gen1 range when new @80 miles) as there were limited public charging spots. Read the details provided in the related thread postings:)
https://mynissanleaf.com/viewtopic.php?f=26&t=5792#p133611
https://mynissanleaf.com/viewtopic.php?f=26&t=5792&start=30#p182547
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Thanks for the suggestion. But it didn't work.

With Home Depot closed today, I tested this by jamming two 100k resistors into the socket end of a PC power cord, and plugging it into the generator, carefully keeping my distance. Same setup as yours, I believe, except the jumper cord had to go in the left hand socket because of the Hyundai plug. It still got the fault indication. I checked the resistance at the plug between ground and each pin before and after several tests that I ran, with the Kona connected and not.

Perhaps the Leaf's cord is less fussy than Hyundai's? A post further up that thread said "A single EU2000i will charge the Leaf at 120V 12A fine."

The thread also suggests jumping the neutral and ground wires of the generator output. Maybe I should give that a try.
 
It could be a generator floating neutral that is the problem. Check your generator manual see how it's wired.
Essentially the EVSE continuously expects to see a current of roughly 0.2 mA being able to be passed from line to the ground wire, much the same as if it conducting into neutral. A normal bonded neutral supply provides that.
At 120 VAC that's 120/0.0002 = 600K ohm which would drop all the voltage. The 100K might be adding too much voltage drop to allow quite enough current. Try 50K in a 1/2W size N to G or just tie N to G if that's allowable per Honda.
 
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I had to construct a ground-fakeout adapter to run the granny-charger from my Yeti power boxes, which have
not even a pretense of a ground connection. The ground is basically just a pilot signal reference, the AC
is what actually matters for charging.

aka, what mike just said...

_H*
 
KiwiME said:
The 100K might be adding too much voltage drop to allow quite enough current. Try 50K in a 1/2W size N to G or just tie N to G if that's allowable per Honda.
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Bingo! I plugged a 50K resistor across the neutral and ground pins of the spare socket on the generator. The Hyundai EVSE cord is happy. The Kona is slowly charging.

Safety checks: I put tape across the resistor to prevent accidental contact, and will make a real plug-in jumper next time I get to Home Depot. The voltage between the car chassis and a grounded conduit slowly cycles between 50 and 110 mV, regardless of whether the charge cord is connected and charging, or disconnected.
 
Toolworker said:
Bingo! I plugged a 50K resistor across the neutral and ground pins of the spare socket on the generator. The Hyundai EVSE cord is happy. The Kona is slowly charging.

Safety checks: I put tape across the resistor to prevent accidental contact, and will make a real plug-in jumper next time I get to Home Depot. The voltage between the car chassis and a grounded conduit slowly cycles between 50 and 110 mV, regardless of whether the charge cord is connected and charging, or disconnected.
Click to expand...
Good back up just in case, glad the resistor idea worked for you;)
 
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Orchardman said:
So, what did you end up with MPG-wise, Toolmaker?
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Well my Yamaha 2kW inverter generator should be very similar fuel consumption to the 2kW Honda EU, under partial load it can run on a gallon of gas for 8+ hours, but full load will bring that down to around 4 hours. Charging at 1.3 kW/hour would bring it close to full load. So you would be looking at roughly 5.2 kW per gallon or assuming an summer efficiency of 18.9 kW/100km = 27.5km or approximately 17.2 miles per gallon.
 
2 to 2 1/4 gallons of gas added 46 miles to the GOM. So say around 21 - 23 mpg. This was premium, so possibly less efficient than the regular that the generator prefers.

@apu shouldn't it be charging at 120v x 12A = 1.44 kW?

20211126_164516(s).webp
 
apu said:
Probably, I was just going by what my car displays(1.3kW) when I plug in the granny evse at 12 amps, maybe the extra 144 wats goes to some sort of overhead for the EVSE/onboard charger or the electrical supply is closer to 110V ?
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My car displays 1.4 kW. What does your voltage measure while you're charging off it?

My generator output measures 128v no load and 124v while charging the car. It's supposed to be sine wave.
 
I ran one more 2 1/4 gallon jug through the generator, adding about 18 mpg per the GOM, compared to 21 - 23 mpg earlier. That was premium; this was regular. The GOM might be a little stingy today due to a longish freeway trip yesterday.

I should finish up the stale gas tomorrow. Then get fresh gas and stabilizer, and wait for two more years or the first PG&E blackout, whichever comes first.
 
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