As a safer than sorry (and i wanted some more reserve time) action, i dropped a fresh battery in my Legacy this weekend. Being the battery was OEM, and knowing the previous owner was a lazy **** who blew the engine out of the car, I simply assumed the worst. Well, upon pulling the battery, it turns out that it was actually replaced by another OEM one. Build date on it is 2010, and it really wasn't having any problems starting the car as the temperature dropped. It's the standard Group 83 that just about every Subaru in the universe uses, and it's the 80-month maintenance free unit. Pictures can be posted if you REALLY need them. $30 OBO
I'm pretty sure my 2005 Legacy is a group 35 (and I think the '02 Outback was the same). Alternate universe?