It's a mystery - that is, it's varied, for some reason. The purpose of this thread should be to try to find out what's going on.
For me, the battery life is terrible. Fully charged before bed, I can just make it through to the next evening. I don't use the LTE feature during the day. I don't use the bezel to turn on the face. I did use it for exercise for 40 minutes.
The second day, same conditions, I didn't make it even to the afternoon, after putting it on fully charged the night before.
1) Watch face. Does it matter the complexity of the watch face?
2) Brightness. I do like to comfortably see the watch face. What are your brightness settings?
3) Bluetooth. I connect to an iPhone, leave it constantly connected.