Battery should not overcharge provided your converter is functioning properly.
2020 vintage trailer should have a decent 'smart' converter/charger
Smell from electrical panel needs investigated
Check that ALL terminal screws inside the panel are TIGHT
From the CBs, at the ground bar, at the Neutral bar, at the DC Cable lugs on fuse panel
Look for ANY burnt signs....melted insulation
Electrical smell means loose connections or melted insulation which can end up arcing/burning---FIRE
Is it time for your medication or mine?
2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31