RE: 2000 Watt Inverter Install Tips Needed
I don't know why you would want a "switch". All the inverters I've seen and used have a switch on them. Just leave it off when not in use. Use only the short battery cables that come with it. I don't see why you need a fuse, either. There should be fuses, or breakers in the inverter. Mine was very simple. Mount the unit, attach the battery cables. Done.
If yours recommends fuses, or switches, follow the directions, though.
If you add a second battery, you definitely want to use an isolator.