Apple has confirmed that it has been deliberately "throttling," or slowing down, some of its older iPhones, namely the SE, 6 and 6S, and 7 series.
It has been slowing phones when their lithium-ion batteries start to age.
Battery performance diminishes over time, the BBC reports, and can lead to a shut down if it can't handle the phone's processor running at full speed.
Apple acknowledged shutdowns were happening to iPhone 6 and 6s models earlier this year, and now we've learned of its apparent solution.
Apple says at times when peak processing power is being used, it slows down phones with batteries that are old, have a low charge or that are cold to prolong battery life.
"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," an Apple spokesperson told the BBC. “We’ve now extended that feature to iPhone 7 with iOS 11.2, and plan to add support for other products in the future.”
Isn't it kind of Apple to reveal this?
Err not exactly. Apple only revealed this after multiple iPhone owners picked up that their phones had started to slow down, and began sharing their stories on Reddit.
This led John Poole, of Primate Labs, to share results of diagnostic tests he ran on several phones, in which he found them running at slower speeds than previously.
"Because degraded batteries last much less and end up with a lower voltage Apple’s solution was to scale down CPU performance, it doesn’t solve anything and is a bad experience," he wrote, "but it’s better than having your device shutdown at 40% when you need it the most."
How can I stop this from happening?
No need to rush out to buy a new phone, if you find your phone is being slowed down at peak times for this reason, it's much cheaper to just buy a new battery.
This costs a far more reasonable $79 from Apple (with a year's warranty), or less from a 3rd party dealer (but in buying from them, you may be voiding your Apple warranty).
By not confirming this until now, Apple has come in for criticism because some owners may have ended up buying a new phone thinking their existing phone's processor was slowing down.
But TechCrunch notes Apple did effectively confirm this was happening back in February, but wasn't transparent enough to make it explicitly clear to users.