So, maybe I'm lucky, but I'm still on the stocker at 93k miles on my 2011 MR, and it's still turning over fine. This past winter, I had no issues, in fact, I can't remember any cranking issues with this car.

I'm curious as to what the life expectancy of the stock battery is, in terms of time, rather than mileage.

Well, mileage too. Does anyone have the maintenance schedule for the battery?

 

These stock batteries seem pretty good. My 2011 MR is also still on the original battery. Could be a combination of good parts, plus being inside the car vs under the hood. Also not abusing the battery by letting it discharge too low goes a long way in extending the life.

 

2008 GSR. mine died around 100k, ~7-8 years?

 

Same here, mine went 8 years and about 87k miles. Not bad for the brutal AZ heat