New trailer, need to install two batteries

[Pbois334]

We just purchased our first TT with plans to start doing more camping. A step up from out pup. I picked up a 2008 Trail Cruiser 21rbh for its bunks and light weight. The first mod I would like to do is add a second battery.
I fist have to say that I have tried the search function in the forum and can't seem to find what I need. I would like to purchase another battery and install a selector switch. Not sure if I just wire the dual batteries the same as I did in my boat or is it more complicated in a camper?

[whatimmadoboutm]

If they're brand new and of the same specs, is there a reason you don't want to wire them in parallel rather than selecting between them? If I were running my furnace or any other significant load overnight, I'd rather have the capacity of both batteries working for me.

Of course, if the two batteries are of different ages or specs, then I see why you would want to install with a selector switch.

[Pbois334]

I already have two brand new group 24 batteries and a new perko battery swicth in my garage. So I figured I would put them to use in the new trailer

[Lwiddis]

"The first mod I would like to do is add a second battery."

Generally adding a battery is ok if they are the same make, model and age. Consider that if the one you have is good quality. If not, two 6 volt GCs like WINNEBAGO Bob suggests.

[Winnebago_Bob]

If I was adding batteries I'd throw 2 six volts on there. I had that set up on my Arctic Fox 28F and it was a good decision.