Also keep in mind that the TV's, DVD players etc. always have some current draw while they are plugged in even though you may not be watching them. That will draw down your batteries while using the inverter as well. I always keep the TV's and DVD player unplugged until I use them. Hope that helps some.
Our older Tripp-lite inverter installed in earlier model years, has a documented 12 amp current draw all by itself when sitting idle while generating 110v for any need no matter how small. Like the TV and DVD player and GFI outlet require some minor amount of 110v. This keeps the inverter inverting 110v, drawing that 12 amps. The inverter never gets a chance to go into standby mode which would then draw only 1 amp.
I leave the TV and such plugged in, but kill the inverter using the switch on the inverter itself. That is the only way to be assured of no battery drain, yet allowing 12v opperations to continue. Killing the inverter using the kill-all switch by the entry door kills both 110v and 12v which shuts down the fridge which is a very bad thing while on a trip.
I wish the Tripp-Lite control panel was a kill-all switch. When the control jack is unplugged from the backside of the panel, the best it will do is place the inverter into the 1 amp mode. That is much better than leaving it to eat 12 amps, but not as dead as flipping the switch on the inverter itself. Of coarse when the inverter is off-line, the programed TV & radio stations all go bye bye.CLICK HERE
to go to my detailed article on the Tripp-Lite subject matter. Maybe something will apply to the Xantrex.