Running entire TT off batteries

fitznj wrote:
Maybe I don't understand the question but every TT I have owned has a 12V furnace, so why would you need 120V?

The only 120V items are the AC, microwave and some of the outlets but the furnace will run on 12v whether you are plugged into shore power or not.

Did I miss something here?

The OP obviously has a limited understanding of his trailer's dual electrical system ... he's simply asking if it's possible to connect an inverter to run his trailer "whole house" and as already indicated the answer is "Yes, of course". I did just that with a 1000 watt sine wave inverter, installing it in my trailer's front pass through storage compartment where it would be out of the weather, well ventilated, safe from those with sticky fingers, but close to the tongue mounted battery. Currently I power it with just a single G27 battery so my use is limited but within those limits the trailer behaves just as it would when plugged into shore power. With dual 6 volt batteries the OP is even much better off so if cost isn't an issue I'd suggest he invest in a quality 2000 watt sine wave inverter and install it in a similar fashion. Yes, he could set it up with an automatic transfer switch for even more convenience but I find that simply plugging the trailer's main service cable into the inverter when shore power isn't available works just fine. Sure, a larger inverter idling does draw more power than a couple of smaller inverters just turned on as required to feed specific devices but the convenience of powering everything running on 120 vac, including all the receptacles, can't be beat and especially if a remote is mounted inside the trailer a larger 2000 watt inverter can also be turned on/off as required, limiting any unnecessary draw on the battery.

Pics of my own installation (7 pics).