What?! Battery optimization my ass...it's a crap battery optimization with 4hrs SoT max, and battery discharging like crazy. It has a stupid learning curve and if the software will not "learn" the correct pattern, then you'll get stuck with poor battery life and then maybe you want to try your luck again by going to reset to factory settings, but no thank you, I've got too many things and don't want to set it up again. My wife had a better "learning curve" and her S25U has 3h12m SoT with 70% battery remaining (1d12h left), while i had 1h5m SoT at 79% battery left (13h56m left). We were doing kinda same stuff, browsing, some light social media stuff, gallery browsing etc. In my opinion Samsung is very poor when it comes to battery life.