Battery Disconect Switch

tshirtman wrote:
Ok OK, just tell me if you can run both rv batteries in (aluminum box) on ONE disconnect,????...

Here is the back side of that switch. The "com" on the left is the common line to the trailer. The + of one battery goes to the post on the right, the + of the other battery goes to the post on the bottom. You can select either battery or both batteries or disconnect entirely.