4000 watts should start about any RV air conditioner if all is in good condition. Did you try turning off all breakers in the RV except the main and air conditioner circuit? Otherwise the air conditioner may need a start capacitor or other service.
3000w inverter? Was that OEM? Should have 6 to 8 batteries to run close to the rating. But then even a single battery should run a tv 12 hours. Any chance the inverter is running the fridge or water heat on electricity?
13.7 to 14.1? Is that amps or volts? Really need both to know if the battery is about full.
The 12 Volt Side of Life
