if you are using the trailer with it plugged in, the battery is being charged... its highly unlikely that you are using more amps than your charger/converter puts out, so the battery should already/still be fully charged when you unplug from shore power when getting ready to leave.
this means you dont need to remove the battery and take it with you..
and if you dont get back to the trailer for a few months, just plug it in when you do and the battery will again get topped up WHILE you are using lights and other 12v devices...
if you have Phantom loads that are drianing your battery when you are away from the trailer, install a battery disconnect... or remove one of the battery cables from a battery post. a good fully charged battery, disconnected from the system, should still be holding a decent charge after 8-10 months..
2007 M-3705 SLC weekend warrior, 5th wheel
2014 Ram 3500 CC/LB, 6.7 Cummins
2004 Polaris Sportsman 700
2005 Polaris Sportsman 500 HO
1979 Bayliner 2556 FB Convertible Cruiser
Heavy Equipment Repair & Specialty Welding...