The new option is labeled as ‘Beta,’ and can be found in the Battery section of the settings app. It includes some informational text for users, a readout of your battery’s Maximum Capacity, and an assessment of your battery’s Peak Performance capability.
Obviously we’re testing this feature on newer phones with healthy batteries, but if you have a degraded battery, you’ll see a Power Management option. Apple outlines how this will work in its recently updated support document.
Additionally, users can see if the performance management feature that dynamically manages maximum performance to prevent unexpected shutdowns is on and can choose to turn it off. This feature is enabled only after an unexpected shutdown first occurs on a device with a battery that has diminished ability to deliver maximum instantaneous power. This feature applies to iPhone 6, iPhone 6 Plus, iPhone 6s, iPhone 6s Plus, iPhone SE, iPhone 7, and iPhone 7 Plus.
Developers can download the new beta at the link below.