Apple today released the second developer beta of iOS 11.3, notably adding previously promised battery health monitoring features, as first spotted by 9to5Mac. The new Battery Health screen apparently appears only for the specific iPhone models affected by the iPhone throttling debacle.
Even though it’s contained in a beta version of iOS, Battery Health is specifically labeled as a beta feature — a word typically used by Apple to reflect the prospect of incomplete and/or inaccurate performance. Its menu currently includes only two headings: Maximum Capacity and Peak Performance Capability. Measured on a scale beginning with 100%, Maximum Capacity tells you how much of the battery’s capacity remains compared with when the battery was new. Peak Performance Capability apparently provides guidance as to whether or not your battery is supporting normal peak performance; it likely becomes a toggle to disable performance throttling if the battery is exhibiting issues.
In separate comments to Senator John Thune (via The Verge) today, Apple suggested that the battery monitoring and performance throttling features might not be necessary on the iPhone 8, iPhone 8 Plus, and iPhone X. In a letter answering questions previously posed by the senator, Apple said that “hardware updates… allow a more advanced performance management system that more precisely allows iOS to anticipate and avoid an unexpected shutdown.”
While a generous interpretation might view the hardware updates as standard in-line improvements to new devices, another view is that this is effectively an admission of a chip or hardware design defect affecting certain iPhones. As the battery issue appears to be widespread, the Recode report notes that Apple is considering rebates to users who paid full price for iPhone battery replacements prior to its recent battery discount program.