One more affected Sq2 here.

I don't know when I got the 2.66 update but as of a few days ago, out of the blue, the watch lasts less than 24h on a full charge, after more than a year of 10+ days on each charge.

I haven't found any tool to troubleshoot…

Edit - battery drain is not solved. Just charged the watch and I have lost 7% in 15 minutes without doing anything and also with 2 restarts...

Tried to reboot, reset watch, charging overnight, turning off for hour, nothing helps.

Drainage is 1%/hour and it was 1%/3 hours before that update

This happened to me this morning. Tried everything. Ended up taking it off and putting it on charge then it shut up! It was on 25%

As the watch ages, it can't withstand the vibration power requirements at lower charge levels. If you want to extend the battery life, try completely disabling vibration.

Not the answer you expect, but if your watch upgraded to 11.14 firmware, when you pay check if your selected card was charged. Happened to me 2 times to pay with one card and the other to be charged. 

As for what you asked, I didn't see a way to change…

The va5 is the same - It drops when I go to another room.

Wifi would drain the battery very fast.  How often do you charge a Galaxy?

The same problem occurred on my wife's Vivoactive 4 watch after the time zone update last night. The charge dropped to 50% in a very short time..

Agree that it does impact battery. To me it seems worth it for sleep because I have found that if I wear the watch overnight and have it turned on for sleep I end up at around 70% battery each morning. Then, it charges fairly fast so if I charge it while…