I mentioned that. That's iOS 11.3. It's in public beta now. It's going to be released in the springtime. It's going to give the user more information about their battery.
We already do provide a lot of information on our support pages, on our website, but under 11.3, you'll be able to see on your phone the state of the battery and the performance. If you wish to have these features on, it will turn on the performance management, and it will notify you when it's time to replace your battery.