Mexicowanderer, im not sure you are writing whet you mean and getting your point across. Hot under the sun?
I dont think anyone here, I hope not, would ever consider using an automotive battery, this is pure nonsense, that has not even been discussed in this thread that I recall.
I think the general consensus is that 6 volt batteries are better for RV use simply because they have thicker plates. If the 12s had thicker plates then we would not be discussing. Most will buy batteries at an automotive shop or walmark where they are easy to get and easy to warranty and easy to find exact replacements for, so we are mostly discussing flooded lead acid batteries. The differences being the 12s are Marine and the 6s are Golf cart; compromise batteries vs a true deep cycle batt.
the 12s have to be paired with same age/same voltage SOC while the 6s don't care.
Yes, for large, high current, high amp draws the automotive battery will deliver, once or twice, the Marine batt will do pretty good as it is able to surge more amps to high draw appliances, but not take as many discharge/recharge cycles at a true deep cycle batt,
BUT overall for most RVers the true deep cycle (the 6s) will give the longest life and the best preformance for most RV needs.
