To get the longer life in the best cases you've listed, I would have to clean up my in season abuse. I know from experience, my house will, too rarely, see a full charge in season. They can go weeks discharged quite a bit(unlike winter).

I'm working on a solar panel installation. I'm afraid I look at batteries like diesel or CNG. They're cheaper than both of those on a cost per season basis, so I don't get serious enough to squeeze out another couple seasons.

Again thanks, either way works.