No, your problem is quite unusual. Judging from postings here, normal battery life seems to be four or five years, tho' YMMV.
Do you do frequently do things like run the stereo for an hour or more with the engine off? How about leaving the lights on? Some folks have normal (to them) habits which are heck on the newer small batteries like we have in the E. How about an aftermarket alarm system?
Other than that, get the alternator and connections checked. A bad diode could be cooking the battery, or a bad connection could be chronically undercharging.
Do you do frequently do things like run the stereo for an hour or more with the engine off? How about leaving the lights on? Some folks have normal (to them) habits which are heck on the newer small batteries like we have in the E. How about an aftermarket alarm system?
Other than that, get the alternator and connections checked. A bad diode could be cooking the battery, or a bad connection could be chronically undercharging.