You can run your generator all month if you like. Unless it gets too cold and your webasto is not working or you have a wore out set of batteries, that probably is not necessary.

Run it in the evening before you go to bed to make sure your battery voltage is up sufficiently enough (14.1 and 27.8) and shut it down till you get up.

I will post a picture of a cheater tomorrow unless someone beats me to it.