One way to do it

I heard a generator running. I scanned the parking lot and there it was.

Van dwellers who spend a lot of time in hot locations end up wanting/needing an air conditioner that runs when the engine is off and when they don't have access to shore power. Some hope they can run the AC from solar power. They can't. At least not for very long. Air conditioners drain batteries faster than the sun can charge them—at least with a system small enough to be portable.

So this person has a generator mounted on the back. It was about 7:30 in the morning and nowhere near warm enough to require air conditioning. It was mostly overcast, and the solar panels wouldn't be getting much sun yet, so maybe the generator was charging the batteries. At least I hope the generator is for more than the air conditioner.

There have been times, after a few overcast days, with the batteries getting kind of low, that I contemplated the benefits of a generator. But then I'd remember the negative side of having a generator. The initial cost... the room it would take up... the noise... one more thing to potentially go wrong... the possibility of theft... It's easier for me to adjust the way I live so that a generator is unnecessary. Use less electricity, relocate to where the sun is shining more yet isn't too hot or humid. That's so much easier. Easy is good.