Forerunner 945 battery drain after 7. 10 (7.20 included), 8 % down during 6 hours sleep

Since this began for me I had mostly 8 days easy before I had to charge.

I run every day, and I hav very consistent mileage. Then suddenly 4 days battery now with the strange jumps in charging % in the end.

For me it didn’t start until weeks after latest update, so I’m thinking maybe it’s not the software, but the battery that has som kind of issue.

In case it is actually a hardware issue and you have warranty left: contact Garmin Support and chances are they'll replace it. 

It still may be a set of conditions that doesn't occur always/for everyone, but 'the stars have to align' and once it starts happening, it's staying that way.

Or it can be an issue that only depends on hours of use, number of charge cycles etc., and the release moment of FW 7.10 was simply a coincidence. Or maybe the battery management strategy was or is not optimal. Or.. We'll never know.

In any case, if there is any chance Garmin will exchange it, it's probably best to do that.

Well i got no “premium” help from customer service. Just “ah to bad we’ll send it in, it’ll probably take 8-10days then we’ll see”

no matter what I asked, I said I can pay for one and then you can send the money back, no scam here, I just want to have a watch when I train. But nope. So now I’m sitting with a 6 month old crap watch, that will have half the usable battery pretty much, or send it in and have nothing to record my training with.

f&@%#…

I guess I have to do that and record my runs with som app or something meanwhile..

I hate inconsistency in my data…

Finally some solution - it`s still a bit annoying to lose 10 % of battery per nigth, but when I changed pulse ox from all day just to night, it significantly improved battery life. I am on 61 % of light activity after 3 days.

I Don’t even use pulse ox.

Give the Wahoo fitness app a try, can connect heart rate strap, power meters, etc.  After activity is over you can export automatically to Strava/MMR, and you can manually 'share activity' or 'export' which sends a .fit file to an email.  Easily import into Garmin.  I used it for a couple years to grab power meter data from the gym spin bikes and get it into Garmin.  

I have the same problem.

Before the last update my 945 battery lasts 10 days with 50Km a week with GPS.

I notice that problem 2 days ago and charge the watch last night, I remove from charge this morning at 8 am and now at 18:00 the battery is 81% (the 945 stays at home all the day).

I don't change any sewttings.

It's incredible!!!!!!!

My watch actually fixed it self, I had three  times with the strange drainage of battery, and then never again.

very strange. But I’m happy.

how? with an update? 

Have u done any operation? Reset or similar?

If yes could u explain me?