My '08 had the original battery, 77k miles. That can be chalked up to living its life in a heated garage, the temp swings were moderate - which batteries appreciate.
But the '08 was totalled by an uninsured driver a few weeks ago and its replacement, a '13 135i, seems to have had its battery replaced once prior to 27k miles.
Anyone wanting to bid on a fixable, salvage title, '08 135i . . . ; -)
http://www.copart.com/us/Lot/30548626