Larry- you will need to supply more info to get an efficient range of help, which is easy to get here on iRV2. With what we know from your above post, there are way too many unknowns to start offering diagnosis options. You are in the right place, however, and should be able w/help to get to the root of your problem using iRV2 as a tool in your kit.
+1 on what EcoDriver05 said, inverter uses 12Vdc battery supply to make 110Vac for plug-in appliances.
Your coach may have one in addition to the OEM battery charger setup. Or you may have an RV inverter which ordinarily combines battery charge function with an inverter. A separate inverter may have been added by previous owner or by Dealer on original sale, or by OEM, and each setup may have its own quirks.
Since you are learning your rig's sertup, start by making yourself a diagram showing shore power plug, cord, whatever the cord ends in in the coach (transfer switch box to choose between cord & generator maybe?), from that device to RVinverter/power center/whatever, etc. This is called a On-Line diagram, and doesn't need to be fancy, just as complete as you can make it. Don't worry if you don't understand the parts, just put them in their place on the One-Line with the most info you can take off their labels. Once you post that sequence here, you will probably find other Pace owners who have a similar enough setup and have had your draw-down problem
so that you can get good ideas for diagnostics.
Also, I believe your Pace Arrow was a Fleetwood product
, and you could close this thread w/a note that you are moving the query to that Forum. Other Fleetwood owners hang out there more so than on this general Class A forum, and can offer more targeted advice.