Have you replaced your battery?

[Rocky_imp]

I'm very surprised at the short life of so many batteries - considering that I get 7-8-9 years out of my batteries.
That said, mine sit on a shelf in a cool dry place for nearly six months, but once a month each are hooked up to a charger for a couple of days.
I notice that many of you live in very warm states.
Could it be the constant heat that shortens their lives?