Hi Cobra7: You are new to Airstreams like all of us once were. There are no stupid questions on these Forums. More experienced Airstreamers enjoy helping out a new member. Sometimes the answers are stupid, but the questions aren't.
Seriously, Airstream rather invented the 12v
DC systems in modern travel trailers with their "uni volt" scheme back in the early sixties. It was a "converter", or transformer that converts 115vAC to 12v
DC. Then Airstream made all the lights, water pump, furnace fan, and vent fans run on 12v
DC so you could have all the comforts of home while on a caravan in Africa. It was a good idea.
Since the converter is making 12vDC, why not spend some of it charging the batteries for the next night where you may not have "shore power" to connect to. Modern converters have circuitry inside that properly maintains the batteries and doesn't overcharge them.
Just a reminder, you can not run your air conditioner on household current of 15 to 20 amps. You need about 3000 watts, or 30 amps to start and run the AC. Low current can damage the AC motor.
WBCCI #8607 VAC Region 11
KnowledgeBase trailer renovation threads: 69 Globetrotter, 76 Sovereign, 75 Overlander, 66 Trade Wind Such fun !