Apple recently released a statement which said that a software feature released last year makes the older iPhone models operate more slowly to offset problems with its aging lithium-ion battery.

In a press release, Apple noted that the feature was added because the lithium-ion batteries in older iPhones including the iPhone 6, iPhone 6 Plus, iPhone 6S, iPhone 6S Plus, and the iPhone SE become less capable of supplying peak demands when in cold conditions and have a lower battery charge as they age over time, resulting in the devices unexpectedly shutting down to protect its electronic components. Cnet reports that it will be applied to other Apple devices in the future. 

"Last year we released a feature for iPhone 6, iPhone 6s and iPhone SE to smooth out the instantaneous peaks only when needed to prevent the device from unexpectedly shutting down during these conditions," the statement from Apple read. "We've now extended that feature to iPhone 7 with iOS 11.2, and plan to add support for other products in the future."

The statement came in response to a report from Primate Labs, the company behind the Geekbench processor benchmarking software. In the blog post, Geekbench founder John Poole said that the benchmark results indicated that the processors in the mentioned iPhone models slow down and decrease in performance as batteries age and lose capacity.

For some users, the solution to a slower, older iPhone is to update the battery instead of purchasing a new device. Apple charges $79 to replace the battery of an iPhone that's no longer covered by a warranty. There is also the option to buy a kit online so users will be able to replace the battery themselves. 

Because of the issue, Apple is facing criticism for the company's lack of transparency when they decided to slow the devices down.