just got mine replaced on my 06 coupe. lasted round 3.5 years. took it to the dealer. had it replaced. they pro rated my old battery and charged me 40 something.

 

saw this thread and it looks like i'm in the same boat. i had to get a jump this past week, so I got my battery tested and guy said that the battery test said it detected a "ripple." can anyone offer any insight? is it my battery or do I need a new alternator?

 

i got about 4 years out of my battery, . i guess its bc we garaged it for a year, but seems about right.

 

I've been changing my battery every 3 years regardless if it needs it or not. Here if Florida, the heat kills batteries without any warning. The dealership prorates the batteries and it has cost me $42 every 3 years for a fresh battery. How can I go wrong? Besides, I don't have to worry now about being stuck in the middle of bum f..k during a rain storm.