Tech giant Apple has confirmed the suspicions of many iPhone owners by revealing it does deliberately slow down some models of the iPhone as they age.
Many Apple product users have long suspected that Apple slows down older iPhones to encourage people to upgrade.
The company has now said it does slow down some models as they get older, but only because the phones' battery performance diminishes over time.
Apple said it wanted to "prolong the life" of customers' devices.
The practice was confirmed after a customer shared performance tests on Reddit, suggesting their iPhone 6S had become slow considerably as it had aged but had suddenly sped up again after the battery had been replaced.
"I used my brother's iPhone 6 Plus, and his was faster than mine? This is when I knew something was wrong," wrote TeckFire.
Technology website Geekbench then analysed several iPhones running different versions of the iOS operating system and found some of them did indeed appear to have been deliberately slowed down.
Apple has now confirmed that it made changes to iOS to manage ageing lithium-ion batteries in some devices, since the batteries' performance diminishes over time.
"Lithium-ion batteries become less capable of supplying peak current demands when in cold conditions, when they have a low battery charge or as they age over time, which can lead to the device unexpectedly shutting down to protect its electronic components," the company said.
"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.
"We've now extended that feature to iPhone 7 with iOS 11.2, and plan to add support for other products in the future. Our goal is to deliver the best experience for customers."
