How to save battery power by reducing screen brightness in macOS betaLatest macOS beta introduces the battery police.
Apple occasionally offers updates to iOS 10, watchOS 3, tvOS 10, and macOS Sierra as closed developer previews or public betas for iPhone, iPad, and Mac. (Sadly, no public betas for the Apple Watch or tvOS.) While the betas contain new features, they also contain pre-release bugs that can prevent the normal use of your iPhone, iPad, Apple Watch, Apple TV, or Mac, and are not intended for everyday use on a primary device. That's why we strongly recommend staying away from developer previews unless you need them for software development, and using the public betas with caution. If you depend on your devices, wait for the final release.
There's already a feature on many of your Apple devices that lets you know which apps are using up a significant amount of your battery, but as MacRumors reports, Apple has extended that feature to include your display.
"... when a Mac's display is set above 75% brightness—or at least 13...
Source:
How to save battery power by reducing screen brightness in macOS beta
