Check the manufacture date of your watch to determine approximately how long the battery has been in the case. (The 4 digit code between the south interhorns. First two digits the week, second two the year of manufacture). The battery is likely to have been in use for over two years, perhaps closer to three years. Even though you purchased the watch less than two years ago, the battery is likely well below full strength by now if it was installed around three years ago. My B-1 began to lose sync quite often when the battery was about 2 1/2 years old. Of course, battery reserve is dependant on how much you use the backlite, alarms and to a lesser extent the other digital functions. After a basic service (cleaning, battery, seals, hermeticity test) the watch has lost sync one time which happened two days ago. The current battery has been in place about a year and a half now and I use the digital functions and backlite quite a bit. Bottom line, when the battery is fresh, the watch will likely hold sync very well for the first year and often well beyond that. The battery life itself is specified to be 2-3 years and usage varies so the laws of physics apply. I certainly recommend having the basic service performed on the watch while still under warranty which BTW extends the warranty another year for the piece. Hope this helps..
Best,
Ron
PS. A good solid "bump" to the watch such as whacking a doorframe while entering a room will also knock the watch out of synch.
