Alvin, your 2017 Newmar Ventana came with either six or eight (6) volt batteries and a large inverter. Your coach will run down the road all day, charging your batteries and powering your residential refrigerator. If you don't run the generator and don't go crazy using other items, you should be able to go about 24 hours on your batteries before you'll need to plug in or start your generator.
When we boon dock, I run the generator for about 2.5 hours in the morning (during breakfast and showers) to bring my batteries up to full power and for about 1.5 hours in the evening during dinner.
You'll be surprised how simple it is to manage an all electric coach unless you plan on boon docking weeks at a time.