Out here in the harsh desert environment a battery will usually only last a couple of years... maybe three. After that you're just living on borrowed time. Even with a battery tender. And, I carry jumper cables in a saddlebag too.
I got my last battery at Batteries Plus. Same exact Deka battery (minus the bar & shield) for about $30 less. Oh, and it comes with a 24-month warranty instead of 12.
I ain't no saint, sure as hell ain't no savior...
Every other Christmas I practice good behavior.