It's nice to have that battery there in case of a power outage. They you still have lights, furnace, some will need it to keep the fridge going even on LP, and a few other things.
Since I have a 100 amp lithium and 200 watts of solar I didn't even bother to plug in during an overnight stop since I didn't need AC.
2017 SLX 195RB
2021 Jeep Grand Cherokee Summit L 5.7L V8
Andersen WDH hitch, Renogy 100 AH Lithium &
200 Watts solar panels from Renogy
Prev. '14 Jeep Grand Cherokee Overland, gas 3.6 V6