In Baton Rouge, there is a radio show that is hosted by a mechanic that owns a shop in town. He said he replaces the batteries in his cars every 3 years. He said he would rather change it when it is old and still working rather than wait until it stops working and leave him stranded somewhere. I never thought about it like that but it makes good sense.
My OEM battery lasted exactly 3 years and 3 months. Back in January, the Jeep started normally, I got to work, and then blammo, no more start when I went to fire her up after work. Luckily, I had a battery shop that carried high quality replacement batteries within a few blocks from where I was parked. The down side was that the shop wasn't open at 11:00 p.m.
I had intended to buy one of those Lithium Ion jump boxes for just such a day, but did not have the opportunity before the battery failed without notice. Sadly, most of today's computer-intensive vehicle choices have battery failures where they go from a successful start to a no-start condition with zero notice. Many stock batteries today don't make it to the 3 year mark- the two vehicles I had before the Jeep(s) had OEM batteries that lasted 20 months and 18 months respectively {I'm talking about YOU, Varta} before they would not charge properly and resting voltage was lower than required to allow a normal start.