Tested charging my Leaf with a 3500 W propane generator and my upgraded Panasonic EVSE. First thing I did was to ground the generator to a real ground. (house ground to ground lead on generator frame) Then I set the EVSE to 6A at 120V and plugged the car in, charging started perfectly. I bumped up the amperage and repeated the previous steps a few times until I got up to 12A, worked every time.
My next test was to try to charge on 240v. I set the EVSE to 6A and plugged the car in. The blue LED on the dash started blinking but the generator didn't seem to be loaded (no change in engine sound). After a little while, the blue led stopped blinking indicating that the car wasn't charging. I plugged in a "Kill-a-watt" meter and adjusted the engine speed to get exactly 60Hz (voltage was within tolerance). Still the car wouldn't charge on 240v. Just for fun I plugged in a small (500w) electric heater to the generator then plugged in the Leaf. Now the car started charging. - Weird -
I repeated the above experiment several times and unless the heater was on, the car wouldn't start charging. (I can turn the heater off once charging has begun). I was able to bump up the amperage all the way to 12 (quickly turning off the heater once the car started charging). I didn't go any higher than this since the generator is rated at 2800 W (3500 surge). At 12 Amps that's 2880 W, slightly over its rated output. Besides, the generator seemed to be working pretty hard!
So now I know that if I have a long power outage at my cottage, I will be able to charge up the Leaf to get back home.
Here is the generator I am using (bought used):
http://www.amazon.com/All-Power-America-Propane-Generator/dp/B0035I1UOO