Leaving the fifth wheel plugged in

Not sure there is a "technical" reason to do so. We leave our Alpenlite plugged in year round. It is stored at home. I like to go out and tinker with things and it is much more convenient to have power. It also helps keep the batteries charged. I do shut off the refer if the rig sits more than a few weeks. I have also been known to run a small electric heater during the very cold spells we can have just to make me feel better.