I have had my Gear S for nearly 4 months. Then just a few days ago the battery decided to die in less than 24 hours. Did the same thing over the next few days.
I was just about to take it back to Verizon to use the 1 year manufacturers warranty on it, so I reset it to factory settings. This seems to have fixed the problem, because I charged it and hooked it to my phone for the day to see how fast the battery would go. Its been over 12 hours and the battery is still at 89%!
So before you freak out, try the reset. You will need to set it up again, but if you love this item, it will be worth the effort.