I had a 1988 Damon (built on a one ton Toyota chassis.) That unit had a solid state battery isolator from the factory. It worked great until it didn't work at all. I replaced it with a constant duty solanoid type isolator. It then worked great again.
The shortfall of my system was the 60 amp alternator. It could barely keep the chassis battery charged when the headlights were turned on. A conversion to a 150 amp alt gave better charging but took extra power to spin the alt, something that my 110 hp engine didn;t have an abundance of.
I forgot to say that from what I have heard, if you want to add a second battery to your coach, the batteries should be installed together as a pair. Adding a new battery to and old battery will give you two old batteries because the old will draw down your new much faster.
