I have a S5 from AT&T and it is connected to my Gear Fit. My Gear fit is the top battery user at 19% followed by Android System at 16% and Screen at 14%. Everything else is under 10% including Android OS. I would find my battery down 8-10 within 1-2 hours but I would listen to music via Bluetooth in the car ride to work which is 45 minutes. It has been 8hrs and 45minutes since my phone was at 100%. I am now at 58%, so about 5+% an hour drop. Now my usage is email, web browsing, light facebook, LinkedIn. No heavy video and have Wifi turned off but bluetooth is on for the Gear Fit.
Also, it took two hours of charge time to go from 10% to 37% charge last night which seems rather slow. I was plugged into a USB 3.0 slot on my PC. My iPhone 5 would have been at or close to 100%.Hoepfully it gets faster over time.