OP, tell us what brand of 45 amp charge controller came stock in your new camper. It may have a huge effect on charging time and how much you have to run the generator. You can probably find it in the paperwork that came with your camper.
Try looking for a WFCO owners manual in there. If it is indeed a WFCO, then you might consider wanting to upgrade it to something that makes more efficient use of the generators gas consumption and run time. WFCO's are good at being in full hook up campgrounds to maintain the battery, they are not good at recharging while boondocking or dry camping. Many manufacturers install them because they are cheap /inexpensive.
Also tell us about your battery /batteries in your camper... are they group 24 or group 27 and how many amp hours are they rated at at 20 hour specs. 75, 85, 100?
