iPhone battery life has been a growing concern, particularly since the performance throttling snafu that started at the end of last year. With the Battery Health beta available in both iOS 11 and 12, the latest version also offers improved battery statistics as well.
Paired with the new Screen Time software, the enhanced battery statistics in iOS 12 help users get a better picture of how they’re using their devices, understand system resources and more. While iOS 11 offered some battery data, iOS 12 brings more specifics, including graphs.
Note: iOS 12 is currently only available as a developer beta, you could experience in 3uTools, a public beta will likely be released sometime soon.
Open Settings
Swipe down and tap on Battery
You can view statistics for the Last 24 Hours or Last 10 Days
Additionally you can toggle between battery usage by app (shows a %) or usage time by app
In addition to the graphs for battery level and usage time as shown above, iOS 12 offers a breakdown of Screen On Usage and Screen Off Usage.
Along with being helpful to better understand your usage, this data can be great to track down apps that are using more energy than expected.
Source: 9to5mac