My Royale has a small (1.5 amp) maintaining charger on the Gen set battery to keep the battery up using 120 volt AC. My Royale has the gen set gauges on a panel over the drivers window which includes two gauges for the house batteries. One is a volt meter and one a amp meter. I keep one of the inverter panels in the gauge mode set to actual battery voltage which gives a temp corrected voltage reading.
My Royale has a pro-air evaporater added to the dash air system. The second evaporatrer is located next to the front TV. The switch is an umarked switch located next to the fresh air knob on the lower dash. It only controls the fan speed the temp is controled with the dash air control. The build sheeet state the proair in under the couch. I looked for a while to find it. Works great.
I do have a Royale owners manual that gives some info plus some info sheets about some operations. Not the best of manuals but if you want to contact me will see if any would shed some light.