Hi jsanders,
There are several devices in your trailer that are considered parasitic current drains. They don't use much power, but if you're talking about leaving the rig in storage, the radio and the propane detector and perhaps other devices will drain the battery over a period of a few weeks. The best approach is to install an inexpensive battery cutoff switch.
If you're worried about current drain while boon docking for a few days, I'm not sure it draws enough power to worry about.