Marien Starting Battery =/= Deep cell battery

True DEEP CYCLE batteries like the GC-2 (six volt) or GC-12 (12 volt) The GC means Golf Car.. are designed to be run down as low as 50 percent (And quickly re-charbed I do not mean fast charge I mean don't let 'em sit discharged for long) over and over and over and over again.

MARINE/deep cycle are basically starting batteries. Like to be above 75-80% state of charge and INSTANTLY recharged when run down.. Not really the best choice for RV use.

Now I've had some folks say "Exact same chemistry so why is that" the answer is they are NOT exactly the same either chemically or physically.. BOth the physical construction and the chemistry are a bit different. A few years ago there was a hugh discussion thread on the chemical differences. and there have been several about the physical differences.. The plates are not pure lead they are an alloy and the alloy is different. also if I recall correctly fewer THICKER plates on the Deep Cycle.

A marine Trolling battery will work well, I've used those in the past.

Deep cycle, not deep cell ;) ... and very few batteries really are truly deep cycle. It you'd paid for this battery and actually use it for dry camping then there may be reason for concern but since it was given to you you're ahead of the curve no matter how you look at it. :D If you normally camp on electric sites then this marine battery will work just fine for the purpose as long as you properly maintain it, it's only when you actually intend to rely on battery reserve to get you through a few days of dry camping that the type & number of batteries becomes an issue. Decide first what your need is then match the number and type of battery to this need ... in my case I've only had one, in fact on our first couple of popups I had none. ;)