Battery-Two replacements in 17 months!!

[BarbaraSATX]

I purchased my 2010 Yaris Hatchback in January 2010. In December 2010 the battery died and I had my car towed to dealership. They replaced battery but told me I needed to drive my car more. Same thing happened today, Aug 2, 2011. I recognize I probably don't drive as much as the average person; I'm 66 and retired and purchased the car last year thinking it would probably be my last. But, this battery business has me wondering. My car now has 8,670 miles on it and I usually drive it at least three times a week. No, I don't drive for long distances, usually about 4-8 miles at a time, and sometimes more. The dealership warned me this morning that the next time the warranty may not cover replacement unless I start driving more miles. I may be old but it just seems a little odd. Has anyone else had this problem, or can anyone confirm what the dealership is telling me. Thanks for reading.