I purchased this watch while deployed in 2007.  It performed flawlessy from that time until about 6 months ago.  At this point, I started leaving it in sunlight or bright interior light to keep it charged.  The display and functions were behaving as though the battery was dead.
I replaced the battery per manual instructions, resetting it prior to new battery insertion.
About three months later, more of the same behavior, no display, going to sleep for long periods only to have to be reprogrammed upon waking up.
Before I replace it, I will replace the battery one more time.
I do this because this device is nearly irreplaceable in my liesure time activities, Hashing (trail running).
With the four actual functions, I can predict local weather fairly well and the necessity of having to correct the time or replace the battery constantly has made this a watch I will replace only if I really have to and it will be with another Pathfinder series!