First i say sorry for bad English since isnt my first language....
I hope that my post can help some people, i did change the telephone (iPhone 8 to iphone7) that uses samsung Health to sync to my watch. Every morning (not so many morning, only two) when I did wake up the battery on my watch was empty, even it was like 80-90 procent full when i did go to bed.
I dont know to 100% it is because i Disney komm the old bluetooth link from my iPhone 8, when i isnt near that phone my phone dont uses lots of battery, in the night when i stay in bed (the iPhone 8 is near as i charge it near me and it is my work phone) my watch did use up its all battery.
i guess the iPhone 8 would try to establish a bluetooth connection like every minute to the active 2 clock who did refuse it and thereby drain the battery.
i did delete the bleutooth connection today from my iPhone 8 who Belinha to my work and hoppfully it Will be ok tomorrow!
kindest regards Peter
There are some things you can do to help the battery life on the watch. https://www.samsung.com/us/support/tip/TIP00085008