12v vs two 6v batteriesJust keep in mind that joining two 6v batts will keep the amps the same, where by joining two 12v batts, the amps will double.
The 6v batts are true deep cycle batteries that allow them to be discharged lower without damaging them. They have heavier thicker plates than the 12v batteries.
Most 12v deep cycle batteries are really ‘hybrid’ batteries. Maybe you can find a true deep cycle 12v , but you would have to have a knowledgable source to locate such.
IMO, it comes down to the size of your battery compartment. The 6v models might be too tall by a 1/2” or so.
As an example, If your battery compartment was under your entrance step, some people have removed the lid and installed some wood trim around the edge. Then reinstalled the lid allowing the clearance needed. 1/2” is not that drastic a change to become used to while going in/out of the rv.
