When you install a third-party battery, or genuine part outside of Apple's authorized repair network, the latest version of iOS shows a new "Service" battery message in the Settings menu that indicates the cell has an undiagnosed problem and prevents users from accessing battery health information.
Apple's new "Service" battery message. | Source: iFixit
Detailed in a repair specialist report and Right to Repair proponent iFixit the new "Service" battery message appears in Settings> Battery> Battery Health menu bar.
Under normal circumstances, the Battery Health line runs out of a light gray arrow indicating an option to get an immediate battery capacity and peak performance report. The feature was first used in response to disclosures that Apple was artificially strangling the CPU performance of handsets with degraded batteries.
After conducting a round of tests, iFixit observed the message "Service" appears when it installed a new battery, even a "genuine" part from Apple. As such, the firm believes Apple has introduced a "sleeper software lock" that requires an Apple Genius or Apple Authorized Service Provider to authorize a battery for use with a particular phone.
Pressing Battery Health shows an "important battery message" that reads, "Unable to confirm that this iPhone has a genuine Apple battery. Health information is not available for this battery." Furthermore, calculations for maximum capacity and peak performance are not recorded. A note under the latter reads: "This iPhone cannot determine battery health. An Apple authorized service provider can operate the battery."
According to a recent video produced by TheArtofRepair, Apple's batteries, like most smartphone phones, are on the market. , incorporates a Texas Instruments bq27546 microcontroller that delivers data related to capacity, temperature and full discharge time. Chips used in Apple's latest batteries also have an authentication module that stores information that can be used to pair the cell with an iPhone logic card, the report states.
The text that appears in the Battery Health pane is mentioned, but not fully explained, in a Support Pages document last updated in March. The links provided point to Apple's official battery service program.
Apple did not disclose the Service Battery Notice in Release Notes for iOS 12.4, nor does the company notice a change in the Battery Replacement Policy on the site (although it states that customers "should" visit Apple or an authorized service provider for support).