Battery life

I'm having the same issue here. battery dead after about 48 hours with not using anything other than it being a watch on my wrist with HR. My 935 lasted wayyyyy longer.

My second charge yielded 7 full days and the watch was at 9% when I started it charging tonight. That is with 3 GPS biking activities, 1 at 1:08 long, 1 at 1:27 long and 1 at 0:53 long. All had a speed sensor and Tempe connected and 1 had a cadence sensor connected. Also had 2 non-gps activities 1 at 0:45 and another at 0:30. Several moveIQ activities as well. Had the o2 sensor off but did manually check it several times. HR on. Backlight at 10% with gestures on. Custom watch face (No Frills). A couple custom widgets. Smartphone mode, notifications for calls and texts only. GPS activities were GPS+GLONASS and the 1:07 one used about 4% battery. Didn’t pay attention to the other two. Was set to 1 second recording. No music. Overall this is similar to what I get out of my 935, maybe a tad worse but I am ok with it. I don’t need the o2 on all the time and can live with just using it randomly. Firmware and maps all up to date per Garmin Express  

SA

My guy feel after a week of ownership is that the battery is not as good as the 935. I appreciate that the watch has a few more whistles and bells than the 935, so at this stage, I am watching closely.

My friend also thinks that his battery does not last as long. 

We both felt that this is something that might get better over time if the watch is new out of the box.

Battery consumption also looked to me to be to high with FW 2.40 but yesterday I started to use beta FW 2.48 and it is very promising. Usage is now about 6-7% a day and it was about 10% in watch mode. 

I've had my 945 for 8 days now.  It's averaging 10% battery use per day.  My Fenix 5x+ used 6%/day with the same setup and usage.  Which works out to 16 days of use for the Fenix, and 10 days for the FR945.  It seems that the battery is smaller in the FR.

I recharged the FR945 after it ran down to 6%.  It took 366 mAh to charge it. There's a tear-down on the web of the Fenix 5X that shows it has a 430mAh battery.  

36 hours of GPS. Not GPS+Glonass and OHR. Not GPS and music.

Garmin clearly state:

"GPS mode with music: Up to 10 hours"

buy.garmin.com/.../621922

You're getting exactly what you'd expect given that you're running GPS, OHR and music at the same time.

after the new beta firmware my battery use went from more than 0.5%/h to less than 0.1%/h !!! that's a nice improvement. Only thing I changed is the backlight after sunset. Now says 42 days in smartwatch mode ! 

I have 945 since thursday. it is monday now. 

second charge is already empty. I did a couple of rides and a a couple of runs. nothing spectial , 7 hours at most.

I have some sensors known to my watch  (3x hrm, 1x foodpod stryd, 2x speed sensor 2x cadense sensor, 2x foodpod runscribe). is it constandly searching for those at full power???