Forerunner 945 battery issue

Master reset mine again last night saying I have 12.3 days of charge at 90% of charge 

I have been postponing the hard reset, but yesterday after upgrading to v6.2 I did it. After the hard reset I fully charged it and during the last 15 hours I have seen 0.180%/h, which is great, with a typical smartwatch usage: connected to my phone by bluetooth, some notifications, no spOx and 24h HR active. I will test the consumption during activities with GPS on this weekend, but up to know the results are promising.

Can someone summarize what the verdict is apart from user settings? I've had mine for 7 months and never had an issue however in the last week the battery is terrible. I went from 100% to flat in less than 24hrs and that was using it as a smart watch, no activities music or GPS usage at all. I haven't changed any settings

Can someone summarize what the verdict is apart from user settings? I've had mine for 7 months and never had an issue however in the last week the battery is terrible. I went from 100% to flat in less than 24hrs and that was using it as a smart watch, no activities music or GPS usage at all. I haven't changed any settings

could yo please define what do you mean by "hard reset"? 

Reset from the watch: System > Reset > Delete Data and Reset Settings

You will lose all your data and the watch will start as new, asking you to select the language, age, height, weight, ...

Thank you, but just to make sure - as per this docs: 

https://www8.garmin.com/manuals/webhelp/forerunner945/EN-US/GUID-1D4D7BAD-1F1A-4EBC-9C74-8D75CCBBF950.html#:~:text=Select%20Settings%20%3E%20System%20%3E%20Reset.,history%2C%20select%20Delete%20All%20Activities.

You can:

• To reset all of the device settings to the factory default values and save all activity information and stored music, select Reset Default Settings.

So in theory you don't have to lose all the data but I guess this won't work , right? :( 

I do not know whether it will work doing it as you mention. I did it deleting all my data and resetting settings to factory default

If that doesn't work do a hard reset

Garmin 945 Hard reset

• Hold the power/Light key until the menu appears.
• Choose power off.
• Press and release power button and the watch should enter the boot sequence
• Press and hold the buttons the Start Button and the Back Button. once the Garmin logo appears
• Beep 1: release START button
• Beep 2: release BACK button
• Garmin watch is hard reset and ready to pair to Garmin Connect again.

That will be like a starting with a new watch

Update from my side: 

I did reset as Lazybird said. Watch has restarted, I paired it with phone again. 

Fully charged to 100% + extra 1 hour on charger. 

I didn't setup wifi, music nor payment. 
After reconnection to my phone It synced my workouts (so I am bit surprised cause lot of people said that they will be gone)

Currently:
Battery Level app is showing mi 93% after 7 hours, which gives 0.693/hour and estimates 5,6 remaining days left 
Battery Monito app is shwoing me 93% after 7 hours but it calculates slightly different - -6,9% / 7,5 hours = -0,9%/hr and estimates 4,2 days left. 

I was using default garmin facewatch (and was bit surprised to notice that it is showing seconds - many users suggestes that face watches showing seconds are draining app). I also found that altimeter was set to auto calibrate , although I turned it of before hard reset but apparently this is a default option. 

So I will try to change facewatch to something without seconds and turn of autocalibration and check in antoher 10-20 hours but  slowly I am losing hope ... :(