How long should Apple Watch battery last when fully charged?

My excersise goals are not very demanding and I use my Apple Watch SE for app notifications, FaceTime/iPhone calls and for sleep tracking and as a streamng box remote and for steaming music directly from my Apple Watch ( and NOT from my iPhone ).

I keep my watch brightness down, too!

My, relatively, NEW Apple Watch SE is getting a little over a full 24 hours.

about 18 hours

Apple Watch - Battery - Apple

M1 Mac mini, macOS 11.2; Watch, series 5 GPS/cellular, watchOS 7.3; iPad Pro 2nd Gen, iPadOS 14.4; iPad Air 2, iPadOS 14.4; iPhone 12 Pro, iOS 14.4; TV 4th Gen, tvOS 14.;  HomePods, audioOS 14.4 and Airport Express w/ Airplay 2