Thank you everyone for your feedback!!!
I think I am going to stick with how it was installed at the factory when that pop up camper was built since I am not keeping it forever. I just wanted to get the refer and lamps working for the weekend.
As far I could determine that the way factory installed the converter, it is on it own separate circuit from the battery and it have a selector switch to choose either the converter or battery to power the water pump/refer/lamps in the pop up camper. (No break away brake on this camper it a small pop up camper)
I will have to check the diagram again but I don't see the battery being connected directly to the converter at all when it was installed by the factory so I assume they installed converter to allow folks run the accessories using just 120v without depending on the battery but offer a switch to switch over to the battery circuit if not using shore power.
Here a photo of the front panel where you can see the selector switch to choose either converter or battery.
When I took the converter out, none of the wiring from converter was connected to the battery directly and it wouldn't make sense to install a selector switch if it on the same circuit.
Bill