My original thinking was much like Slow's--we used to tent camp, and who needs to drag around anything more than a flashlight? Heck, it's usually so bright at night I didn't even use the flashlight.
But, with this "hard sided tent" (aka teardrop), maybe one or two lights would be handy. After all, there are low powered LED lights nowadays, and I am an electrical engineer, after all.
Ah, but once we told my Mom about the build, she insisted we make our first long trip one back East (from New Mexico to Upstate New York) to see her. While camping in the West, we simply go up to cool down, but crossing the Midwest in summer means either dragging an air conditioner along, or suffering. And an air conditioner means a shore power hook-up.
Well, while we have shore power, why not use it to charge the battery?
Oh, and solar panels are now so much less expensive, and wouldn't that be neat?
And so it goes. Our 'lectrical system is now only about as complicated as certain NASA spacecraft.

Tom