iPhone users have often observed their devices slowing down with time. Now Apple has confirmed it's not their imagination, but something the company does on purpose.
All the better for your battery
In a statement, Apple said it changes how iOS operates when batteries degrade.
"Our goal is to deliver the best experience for customers, which includes overall performance and prolonging the life of their devices. 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.
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."
What this means is that iOS tries to prolong battery life in juice-sapping conditions by throttling the phone's performance. Before, people used to wonder if this was part of a larger conspiracy theory. Now Apple's statement probably shows that's not true, but that will hardly annoy anyone less, especially as Apple doesn't make replacing batteries easy in the first place.