I put a battery disconnect switch in to our Bighorn. An absolute "must-do" mod, in my humble opinion. Very easy as well.
Initially, I considered going with an automotive battery disconnect switch, but after doing my due diligence decided to consult with the marine experts. I ended up going with a switch made by Blue Sea Systems (
www.bluesea.com). The switches come in a variety of configurations and mounting options, some even allowing for multiple battery banks. I went with the basic on/off version.
I purchased my switches from my local West Marine store, although they have an excellent web presence as well (
www.westmarine.com).
You'll need to also buy a couple of feet of heavy gauge battery wire with the connectors on either end as well.
I also installed one of these switches in line with the inverter as well, so when we're not needing it, there is zero power going to it.
One thing to keep in mind if you have a solar array is to make sure the solar charger can still charge the batteries, but the house cannot drain anything.
Also,
make certain that you have the battery switch in the "ON" position while driving, otherwise the trailer brakes would not be able to engage in a breakaway situation.
Hope this helps.
Chris