Back in November, it was discovered that the iPhone 6, 6 Plus, 6s, and 6s Plus all had issues that would cause them to shut down without warning. While not all devices were affected, Apple issued a statement to TechCrunch yesterday to say that it has fixed the issue on most devices.
To be more specific, with iOS 10.2.1 - the latest version of the OS - 70% of iPhone 6 and 80% of iPhone 6s handsets won't experience the issue anymore. According to Apple, over 50% of active devices have already upgraded to version 10.2.1, which on a side note, adds a bit of context to the news from earlier this week that iOS 10.x is running on 79% of active iOS devices.
Here is the full statement:
With iOS 10.2.1, Apple made improvements to reduce occurrences of unexpected shutdowns that a small number of users were experiencing with their iPhone. iOS 10.2.1 already has over 50% of active iOS devices upgraded and the diagnostic data we’ve received from upgraders shows that for this small percentage of users experiencing the issue, we’re seeing a more than 80% reduction in iPhone 6s and over 70% reduction on iPhone 6 of devices unexpectedly shutting down.
We also added the ability for the phone to restart without needing to connect to power, if a user still encounters an unexpected shutdown. It is important to note that these unexpected shutdowns are not a safety issue, but we understand it can be an inconvenience and wanted to fix the issue as quickly as possible. If a customer has any issues with their device they can contact AppleCare.
As it turns out, "spikes of activity" would cause older batteries to deliver power unevenly, and would send the device into an emergency shutdown. Users would have to connect to power to restart their device, and the good news is that even if you're one of the few that has a device that's still not fixed, you at least won't have to find a charging cable to boot up your device again.
Since the issue was with older batteries, newer devices weren't affected. This is good news for anyone that bought an iPhone 6s recently.
The changes to the power management system obviously haven't fixed all devices, although Apple will presumably continue working on a solution. Still, this should provide some level of relief for everyone with an affected device.