I suspect your 2007 RV unit does not have a smart-mode converter/charger on-board. These smart-mode units really perform nicely for automatic battery maintenance.
If your converter/charger unit is not a smart-mode unit it will constantly put out 13.6VDC and this will boil out your battery fluids over time. One should check the battery fluids every couple of weeks if the RV is always connected to shore power.
The fix is to upgrade to a smart-mode converter/charger and add a second battery while you are at it. Having 200AH of battery capacity is boss if you like to camp off the power grid for a couple of days over a weekend.
PLAN-B is to keep a close eye on the battery fluids and purchase a digital voltmeter from LOWES, WALMART, or any number of auto parts store, even AMAZON.COM. They only cost $7-$20 and will certainly take the guessing out of what is going on with your batteries. Sometimes when a converter/charger unit fails it goes to 19-20VDC and that will certainly cook your battery big time.
Roy and Carolyn
I claim Horse Creek Country in Southern Ill - Momabear is from North Texas
We live in King George VA
RETIRED DOD DOAF DON CONTRACTOR Electronics Tech 42YRS
"We're burning daylight" - John Wayne
2008 STARCRAFT 14RT OFF-ROAD POPUP with PD9260C and three 85AH 12VDC batteries
2010 F150 FX4 5.4 GAS with 3.73 gears - Super Cab - Towing Package - 2KW Honda EU2000i Gen
K9PHT (since 1957) 146.52Mhz
"We always have a PLAN B"