were separate from the aforementioned defects in the 6S. In December 2017, the developers of the benchmarking tool Geekbench issued a report which showed a pattern of performance degradation on iPhone 6 models upgraded past 10.2.1, and iPhone 7 models upgraded past iOS 11.2. There had been anecdotal evidence in the past that Apple had intentionally degraded the performance of older iPhone models on newer versions of iOS as a form of planned obsolescence, to encourage sales of newer models. In response to these reports, Apple issued a statement to CNET, confirming that it had implemented software performance controls based on battery health on older iPhone devices, in order to preserve system stability and prevent unexpected shutdowns. The company stated that its goal was to "deliver the best experience for customers, which includes overall performance and prolonging the life of their devices", and explained that "lithium-ion batteries become less capable of supplying peak current demands when in cold conditions, have a low battery charge or as they age over time, which can result in the device unexpectedly shutting down to protect its electronic components". Soon afterward, Apple issued a formal apology, admitting that it initially believed that the issues were caused by iOS bugs and "normal, temporary" performance decreases following an update, but that "continued chemical aging" of batteries in older iPhone devices was also a factor. Apple stated that replacing the device's battery would restore full performance, and also announced that it would offer a US$50 discount (from $79 to $29) on battery replacements for iPhone 6 and 6S from January through December 2018, and that it would include more prominent battery health information in later versions of iOS. In January 2019, Apple CEO Tim Cook stated in a shareholder letter that over 11 million battery replacements had been made under the discount program. The company stated that it had never, nor would ever "do anything to intentionally shorten the life of any Apple product, or degrade the user experience to drive customer upgrades." iOS 11.3 added the promised battery health information, and also allows these performance controls to be disabled. Beginning with the iPhone 11, Apple introduced a new performance management system intended to "reduce performance impacts from battery aging". Unlike the previous system, this is always active in response to the battery's current capabilities, and there is no "peak performance" state. Reception USA Today columnist Jefferson Graham