Let's het the terminology correct !
You Xantrex 1000 is an
inverter. It take 12V DC from your battery and make 120V AC. Handy if you want to watch television at night when your RV is not "plugged in". At 1000W, it is not big enough to run a microwave or probably most coffee pots.
This unit does NOT charge batteries !A
converter take 120V AC and make 12 DC to keep your batteries charged and run the lights in your RV. You should have on already installed in your RV
(came from the factory).
They DO make inverters that have chargers built in. Some also have an automatic transfer switch. This means you will always have 120V AC available, either from the RV plug at the campground, or your generator or the batteries. Once installed everything is automatic ! Nothing to do but enjoy life. Plus, you can REMOVE the existing converter, so one less thing to go wrong.
Here is and example of one that would fit your needs
Samlex EVO-1212F-HW 120V Pure Sine Inverter/Charger - 1200 Watt