New TT,Battery intermittent charge issue

[Leevie]

2017 Rockwood 2906ws TT. The battery fully charges when being towed by my vehicle. Upon camping arrival, battery was fully charged. (On a trickle charger at home). We went camping, plugged into a 50 amp service, with a surge protector showing all green lights ok. Everything in the TT working properly the first day, battery was staying fully charged. Second day upon return to campsite, the battery was almost dead, no longer charging. LED lights were very dim, but micro still worked. Ceiling exhaust fans did not function. Slides did not function until hooked up to tow vehicle.
We decided to return home, and by the time we were home the battery on the TT was fully charged again. Is this a converter issue? Why would the battery charge from the tow vehicle and not the 50 amp service? Thanks in advance....

[CHICKDOE]

my guess would be something to do with the converter. you said on second day the lights were dim (12 volt) yet the microwave worked (110 volts). if the converter was working it should be supplying 12 volts to the lights even without a battery connected. since the lights are dim this would imply that they are being supplied by a depleted battery and that there was no 12 volt power from the converter. anyway, that's my read on the problem.