Just spent our first weekend "boondocking" with the new coach. Over the last 10 years or so, most of our camping has been boondocking as we are always out 4-wheeling somewhere with our toy-hauler.
So we arrived at a camp spot Thursday night. Ran the genie for a couple hours to make sure everything was up to snuff before retiring for the evening. Batteries indicated full-charge (14.7 V) when I went to bed. About 6 hours later, batteries indicated 13.7V. And with the fridge running, I was drawing about 21A. When fridge cycled off, amps dropped to 3. So we camped all weekend, and I being the nervous nelly was constantly checking the battery state, amp draw, and what was running at the time.
So to make a long story a little longer ...
Ran the genie twice a day ... a couple hours at a time each morning, and each evening. And when the genie is running, everyone gets notice to charge their stuff (phones, tablets, PCs, etc.) Batteries only once got down to 12.3V so AGS never kicked in but a nice comfort factor knowing it was there.
And consumed no noticeable amount of fuel over the 3 1/2 days we were out. I had thought about the solar option, but it is pricey. My diesel genie is way quieter than my previous gas Onan, so I don't even feel bad when I have to run it.