Upgraded my series 5 to watch OS7 and now battery burns out in 8-9 hours

Thank you.

This is good to know... but... these are known solutions in general.

For me the biggest surprise was a drop in performance from my watch with the last OS which would last a full day (at least 20% at 10pm) with at least 80 minutes of workout. Now, with OS7 I was hitting the 10% power reserve notification at 4pm in the afternoon (hand washing off). I was on a conference call sitting still and saw my watch drop 8% in less than an hour.

I did full reset/re-pair of the watch and that helped. I now hit the red zone for power reserve at about 9pm. Those 5 hours are very helpful. The power usage is still not where it used to be and I haven't changed my behavior, apps or usage profile at all.

BTW... My wife upgraded her series 4 and saw no difference. Still looking for that root cause.... I can't be the only one with this issue.

And.... The suggestion about working out outdoors without HR monitor kinda defeats the marketing message for the watch... just sayin...