I’m currently using a Series 5 watch which has the always on screen mode. I use it to track sleep and I exercise around an hour daily and use it primarily to track water intake, track my tasks, and play music.

It might be my usage, but I’ve never had the problem of it dying unexpectedly. I usually charge it when I’m taking a bath and while I’m reading a book.

I’ve gone through Fitbits and other wearables which don’t need daily charging but I personally don’t have a problem with the battery.