Some users have long wondered if Apple intentionally slows down the performance of old iPhones, and over the past week there have been reports that claim to show that that is the case.
Some Reddit users have found that they got higher Geekbench benchmark scores after replacing the batteries in their older iPhones. For example, Reddit user TeckFire got scores of 1466 Single-Core and 2512 Multi-Core on an iPhone 6s running iOS 11 with the original battery, but after replacing the battery, the scores went up to 2526 and 4456.
Primate Labs founder John Poole then chimed in with charts showing the benchmark scores for iPhone 6s running iOS 10.2 and iOS 10.2.1, and that data appears to show a link between lower processor performance and weakened battery health.
The significance there is the iOS 10.2.1 update. When Apple released the update in January 2017, it said that the update fixed a bug that would cause iPhone 6s models to shut down unexpectedly.
Today Apple came forward and commented on the whole situation, explaining that it "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 the conditions." As the batteries age, they're unable to give the processor enough power to reach a peak, and so as TechCrunch's Matthew Panzarino explains, Apple is working to "smooth out" the peaks but limiting the power available from the battery or spreading the power requests out over multiple cycles.
Here's Apple's full statement to TechCrunch:
“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.”
The logic behind this move makes sense, as older batteries won't be able to give the same power to their processor as they once did. This results in Apple tweaking the performance of the iPhone so that the user doesn't encounter more serious issues with their device.
The issue that many people are taking with Apple's decision is that the company could be more transparent about what it's doing. iOS does tell you when your iPhone's battery is going bad, but Panzarino says that it's "very, very conservative." Apple could change that and be more aggressive about telling users when their iPhone's battery is going bad and also explaining what it's doing to help address its performance.
One of the big takeaways of this report is that if you've got an older iPhone that's feeling slow, replacing its battery could be one way to restore its performance. Apple offers a $79 battery replacement for iPhones if the issue isn't covered under warranty — and wear from normal use isn't — and there are some cheaper third-party options available if you'd rather go that route.