Battery dead every time

Sounds about right. 2 weeks unplugged and mine will be dead.

I would:
Check Converter DC output at converter AND at battery..is it really charging
Check battery voltage with a voltmeter
Check water levels in each battery cell
Then using a hydrometer check each cell specific gravity
Then take battery to any auto parts store and have it load tested

IF everything tests good.........
Connect voltmeter between battery neg. post and neg. cable and measure amp draw
Then start pulling DC fuses to isolate circuit that is draining battery.

YES there are parasitic drains on battery...LP Detector, Radio memories etc. but they should not cause a charged battery to go dead in 2 weeks......several weeks yes.

You are missing something. Radio memory, Co2 detector, propane detector, circuit board for fridge on and on. Disconnect the battery or install a disconnect switch and all will be fine.

B.O.

One of the many things I lernt from this forum is to install a marine grade battery cut off switch. After killing my own battery, the $35 switch was a good investment. It also stops folks from turning on the hitch light or operating the hitch while its in storage.

One should disconnect the battery when not in use, things like the propane detector, "memory" in the am/fm radio, TV antenna amplifier, the invertor standby current and others like moister free features in refrigerators and propane switching solenoids will still draw power.