I work with batteries a lot (backup generators and fire pump are the worst abusers of Batteries as they charge 24x7x365)
So the Basics:
CCA is critical if you are in cold temperatures. Lots of amps is what starts a car, not AH. Bigger batteries have more CCA. AH is meaningless and I have no idea why they even have that. You also have to know what AH rate is (1, 2, 5, 10 hour etc). CCA is at a given temperature (0?) 32 deg (I would have to look it up but does not change.
Cold Batteries: They love the cold, they last forever. Sadly, the chemistry is not the least bit excited (pun) and does not put out the same oomph. So what looks like a bad batter (or deterioration in the cold) is the characteristic of the chemistry.
By the time you get to –20, you have lost ¾ of the output. That’s why CCA is important in the cold, the more you start with (pun) the more you have when its cold.
We have had the original battery since 05, I will change it next summer as the starting in cold temps is getting marginal. In my truck I had the same battery 15 years and just replaced it as some indications it might be going bad (bad starter actually). It was time for safety sake but that tells you how long they last in cold temps (diesel take a lot more ooomph with glow plugs and the compression so more often for them)
Heat: Batteries Hate heat, though they sure put out good until they fizzle. Heat accelerates the chemistry and the breakdown. For each 10 deg above 77 you cut battery life in half (yhep). Under the hood in Texas or Florid or X, its always hot. Ergo, short battery life but good performance before they destroy themselves.
Make Does Matter!!!!: JCI has a good reputation because they use good materials, process and procedures. I would go with the Interstate or the Varga (VW provided). Either should be good. Sometimes a store changes and you don’t know it. If you can’t confirm its not worth it.
Cat used to use Exide. In my applications they would last less than 2 years. We swtihced to the Interstate’s and I can get 10 years. For a standby gen application anything over 3 years is great. 10 years is Jaw dropping incredible (and they are still working!)
The only ones I have seen that come close are something called DBMC out of the Carolinas (or used to be, they may be gone, they were regional only). We got them at the OEM set of the Fire Pumps and we got 7 years out of them (one dropped the plates blew up so we changed them but they were still putting out though the autopsy showed the plates disintegration which is probably what cause the short).
Cheap batteries get you short life in heat and don’t put out in the cold well, or fall off so rapidly that they are useless.
Get the Varta VW or the Interstate, its worth it and you will get many times the life.
If hot climate keep the small Varta, you don’t need the bigger one.