Just another related note, if I run my generator and onboard charger via the AC, my batteries generally charge back up according to the "dumb" led in an hour or so. I can't think that running the truck is any worse for the batteries than the charger. I think the house charger is designed to bring the charge up to a certain percentage relatively quickly. The rest of the charge comes slower to bring it up to 100%.
As someone else noted, as long as you charge reasonably often and don't go to a very low percentage, I think you will be fine using the truck to charge.