Forerunner 745 battery issue

This seems too fast indeed. Which watch face do you use?

I use the default watch face with seconds disabled. 

Now from 21:05 to 7:05 (most time sleeping) I fall down to 51%. 

Means I lost 49% battery in only 10 hours.

Seems to fast drainage. I would lost 20-25 % per day, normal setting (no airplane mode), with so activities too.

I removed Spotify, and use Actiface watch face, with its Power saving option.

Yes, there is probably a technical defect.
Battery consumption is always the same, no matter what settings I have set.

The 20-25% per day, is the watch connected to the cell phone and do you wear it when sleeping?

Yes, the watch is connected continuously to the phone, and even sync at least a dozen time per day, every time i consult GC on mobile. 

But no, I do not wear the watch at night.

I compare the battery % from morning to morning, and I see a 20-25% from one day to the next, even with 1 - 2 hours of activity recorded daily.

Okay, thank you very much for your answer.

I have already contacted Garmin and they will replace it.

Good for you. By the way, can I ask you a different topic: do you use auto prompt (voice) during activities? I cannot get the auto prompt to my iPhone, same I had before with my 645. Same phone.

Thanks and have a good day.

Hello, sorry but I do not use auto prompt (voice) during activities. What should do this feature? 

It will (should) give you an audio alert on your phone (if with you and connected to the watch) or to your headphones (if connected to watch or to phone) every  X km, or X minutes (depending on your settings) with distance, pace, heart rates.