Battery disconnect

[Dwilcox]

Getting ready to take the LaCrosse in for warranty work. Added a second 12 volt battery in parallel. Pos to rig off one battery and Neg to rig off other. I know that the factory disconnect will leave some vampire loads on so I want to add a knife switch like I had in our SOB trailer. The difference is that on this trailer I have added a shunt for a DC amp meter and there won't be room in the box for it. Each battery is in its own box with 12" wire passing between boxes. Anyone see an issue with breaking the ground between batteries? I could add the switch to the un-shunted battery. Both are Interstate batteries, black one is Costco branded, other was new with trailer so about the same age (new).
Thanks for any input.

[Dwilcox]

Oh, and the 2 hots off the green battery are to the Jack, and amp meter, Jack will be moved to other battery and amp meter can be killed.

[WolfWhistle]

What about adding this type of cut off on the + side between battery and rig. But it really doesn't matter functionally if its on the - or +

Side Mount Battery Terminal Batteries Cut Off Disconnect Safety Switch | eBay

WW

[Jay2504]

If you broke the connection on the neg cable between the 2 batteries shown in the picture, one battery, the green one would still be hooked up to the camper. It would complete the circuit using the posivitive jumper between the batteries to connect to the plus side and the attached neg coach cable for a complete circuit. Breaking the jumper between the neg posts would not shut off both batteries from the camper. Jay