I just got a used 2012 Freedom 1950 tent pop up camper.
I went camping, and let the trailer conneted to the 30 amp outlet of the site for a full 4 days.
During that time, i used lights, fan and a few times, the heater.
Fridge was on 120v.
When I got home, only 45 minutes from the camping site, and disconnected the trailer from camper, I heard the gas detector beep a few times. I assumed it was to indicate that there was no external power anymore.
3 hours later, the same detector started to beep something like 30 seconds per minute.
When I got inside, there was a red light on the detector, and I had to push the "test button" ou stop the beeping.
The dealer where I got the trailer told me that it was cause the bettery hadn't been charged enough and that I have to connect an external charger (like a car charger) to fill the battery, otherwise, 3 hours is normal to discharge the battery.
Otherwise, I may disconnect the battery.
That model of trailer has a 35 amp converter w/battery charger.
I got the camper on the 15 of august. got camping for 9 days in a row the same day, got back home 4 days before getting back camping the 4 days described previously, so I don't think I did something dramatig to drain the battery