Thanks for the replies. Under use is not a problem in this case. As we travel, we usually park where there are no services. The generator gets to run for at least an hour in the evening to charge the batteries as we watch TV and work on our computers. My wife and I both use CPAP machines, so by morning, the batteries need charging. I usually let the generator run for 1/2 hour to 1 hour while we're getting ready to roll.
I ran both air conditioners today for three hours. Each air conditioner is a 13500 unit, and the generator worked perfectly. I turned off the air conditioners, and within 5 minutes, the generator was surging. I looked at the panel, and saw that the batteries were fully charged, so the generator had no load.
I turned one air conditioner back on, and the generator got down to business and smoothly provided the power needed to run the air conditioner. I turned the air conditioner off, and within a couple of minutes, the generator was surging. I turned it off.
So, under load it's O.K. With no load it's not. Although, when I first start it, if it has no load it runs smooth. It seems to happen after it has worked hard for a while, then when the load becomes light, it goes into surge mode.
Jim & Kate
2016 Creekside 23RKS, 2014 Ram 1500 Eco Diesel
1995 Monaco Dynasty 36', 2005 Honda Pilot