The Battery section saw one of the biggest modifications, ditching Nougat's battery
graph and list of all resources causing a
drain on your device's battery in favor of a new battery icon and
showing only apps causing battery
drain and not things like your screen, the Android OS, etc..
You can probably guess the point at which I started playing games in the
graph above, and equally unsurprisingly, the image below
shows the main culprits for that
drain.