New up to 4% per hour battery drain

There are more issues reported regarding increased battery use. See for example this thread: reduced-battery-life

But this issue seems different, as you mention Bluetooth is off. Do you have Wifi on by any chance? 

No ideas left here. Total reset didn't help. Last thing I noticed was a large number of items in the sync queue in Express. Some of the updates (for Deezer? will never use that) can not be installed because 'there is an error syncing to connect'. I'm now trying the topo active europe 2020.10 map update for the n-th time.

I'm usually not very explicit to voice my displeasure, because it's not constructive, and I understand Garmin's challenges updating, maintaining and developing for a diverse product range.  But %#!@%#!*&#^&*!@^*!. 

Back to my Fenix 5 Plus for now. Which has some minor issues with the latest FW, but it's just so much easier to use without having to do checks like 'battery OK for a run?' 'did I turn Bluetooth off'?

Thanks for giving the full reset a shot; I'm at that point myself, and now I just won't bother.  It is crazy; I like the new features, but not if they're going to cause insane battery burn.  I just don't get what the wait for a fix is about, this firmware's been out for quite some time now.  

I guess that this issue isn't all that widespread (not everyone experiences it). There must be some combination of this FW + environmental factors that brings it out. So it's probably not a priority. 

As the proper way to report bugs is through local support, I'm doing that.They are nice and helpful people, but I'm afraid they think it is a hardware problem, which it just really is not. It's more likely a 7.20 plus BLE sync thing. Reverting to 6.85 beta might help. Or using a new Connect account. Or Bluetooth sniffing and phone log diving. But I have other stuff to do.

In my case the battery drain started on SW 5.50 and continued on 7.20. It can be GPS/BT, some configurations or whatever else.

That's not encouraging, since 5.50. Well, I'll just wait it out until the new FW. As long as the FR945 has Bluetooth off, it has stellar battery life. But I do like to have notifications on the watch during the day, so Bluetooth off is not a great option.

Just one more thing to try: Make 100% sure the sync queue is empty (see: How to Clear the Sync Queue in Garmin Connect).

I could not get that to work though, the updates kept re-appearing. I did another total reset+wipe, deleted the device from phone and from my account, created a new account, synced via Express, and no pending Deezer, Strava, Spotify updates. Only after all that, I paired it to a phone again and set 'Music Providers' to 'control phone'.

It seems fine - but it's only been 1 hour. Just could not wait to post something hopeful. I'll report back tomorrow.

Thanks for the idea and reporting. My sync queue is empty, so it is not a problem for me. Probably on weekends I will try a full reset.

Another thing I'm curious about; is anyone noticing with the new sleep widget, it's reporting REM sleep as Awake?  That is seriously making my Body Battery reading useless.  It's telling me my sleep is crap every night, even though I'll only get up a couple times to go to the bathroom and go right back to sleep.  I dreamt a ton last night too, but it told me I was awake 2 1/2 hours, and only got 10 minutes of REM, which is obvious garbage.  It does this every night.  Anyone else seeing this?  I'm wondering if there's a correlation with the junk battery life too, because that's where so much of my battery drain happens is just overnight.  Battery drain during workouts is normal.