Microsoft is currently in the middle of developing Windows 10, the company's next major operating system. Every month or so, Microsoft will push a new build out to the public for testing, however public builds are always missing some of the good stuff. For example, upcoming features such as Battery Sense and Data Sense might not be available in the upcoming Tech Preview, but they're already working in the latest internal builds.
Today, more information regarding both Battery Saver and Data Sense has been revealed. According to Neowin, Battery Saver will do just what you expect it to do. Similar to the Windows Phone version, Batter Saver will limit background activity to help, and again much like Windows Phone, you can set this to on automatically once the battery reaches 20% or you can turn it on whenever you see fit.
Data Sense, again much like its Windows Phone counterpart, monitors the amount of data you use and tries to compress it so you use less. Data Sense works great on limited connections, especially as it allows users to limit data when need be.
Other features that are on the way are Overview and Usage, which again are much like their Windows Phone counterparts. Still, considering these new features are early in development, there's a chance we won't be seeing these features in the upcoming preview build.