Following last week's controversy with Apple admitting that it slowed the performance of older phones with aging batteries, the company today published a new letter that further explains its actions and details the new steps that it's going to take.
Apple explains that in iOS 10.2.1, it released an update that "improves power management during peak workloads to avoid unexpected shutdowns" on the iPhone iPhone 6, iPhone 6 Plus, iPhone 6s, iPhone 6s Plus, and iPhone SE. This update dynamically manages the max performance of some device components when necessary to make sure that your phone doesn't randomly power down. Apple says that these changes may experience long app launch times and other performance reductions in some cases.
The response to iOS 10.2.1 was positive, says Apple, so it extended the same feature to the iPhone 7 and iPhone 7 Plus in iOS 11.2.
However, Apple says that it began getting reports from some customers this fall about slower performance in some situations. Originally this was thought to be due to the normal performance impact of upgrading to a new OS and minor bugs in the initial release that've since been squashed. Apple now says that another contributor to these slowed down experiences is the continued aging of batteries in the iPhone 6 and iPhone 6s models.
As a result of this continued aging and in an effort to address customer concerns, Apple is reducing the price of an out-of-warranty iPhone battery replacement. From late January 2018 to December 2018, anyone with an iPhone 6 or later can get a battery replaced for $29, down from the normal price of $79.
Apple will also release a new software update in early 2018 that'll give users more insight into the health of their iPhone's battery. This will help users to determine if their battery's health is affecting performance.