I have a 2006 Tioga on a Chevy chassis also made by Fleetwood.
unless it has been changed out you will have a WFCO converter,these old ones will boil your batteries.You need a newer 3 stage one to replace it.
I replaced mine with one,
Like this one I keep it plugged in all the time and check the batteries monthly and very seldom have to add water over the more than 12 years that I have owned it.
Also look in your Battery Bay to see if you have a BIRD like this one,many of the Fleetwood RVs of this era had them,as mine does. When plugged in to will keep all of your batteries including your chassis battery,that is what it is designed to do.
Click For Full-Size Image.
As for the Die Hards my experience with them was not good I would stay with the ones that you can check the water.