Accusations of Apple throttling older iPhones are again in the news, but according to the company, it is more an issue with older Lithium-ion batteries and Apple's attempts to "smooth out" battery usage to meet peak demands.
In response to the current controversy, TechCrunch contacted Apple about the odd power profiles being generated on phones with the older batteries. The official response:
“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.”
Needless to say, as a battery gets older, it doesn't hold its charge as well. Excessive heat and even overcharging can also play a factor in damaging battery life. It is understandable that once a battery is replaced, performance will improve. And that is not just an iPhone issue, as it happens with any smartphone.
And keep in mind that some shutdowns are happening during times that users are putting their devices through more rigorous activities, such as playing games or watching YouTube. Older or abused batteries aren't able to supply the power they once could, so drain during "peak" times is more evident. Apple is apparently attempting to cap the battery drain and make it more even, rather than actually throttling anything.
Apple dealt with a similar shutdown issue related to its batteries last year and instituted a replacement program.
While a clandestine attempt by Apple to funnel users to the newer iPhones appears not to be the case (again), Apple could definitely do a better job of communicating to its users what it is doing and why. Some transparency never hurts.