Apple’s iOS 10.2.1 Addresses Majority of iPhone 6/6s Unexpected Shutdown Issues


On Thursday, Apple revealed that iOS 10.2.1, an update that the company released a month ago, included a bug fix for an issue that caused iPhone 6s users to experiences unexpected shutdowns.

The iOS point update quietly patched what appears to be a power management issue that in some cases would cause iPhone 6s hardware with older batteries to shut down.

However, the software update does not completely solve the problem. In a statement provided to TechCrunch, Apple notes an 80 percent decrease in unexpected shutdowns among iPhone 6s devices and a 70 percent decrease for iPhone 6 devices.

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.

According to the report, Apple determined that the unexpected shutdowns were caused by intensive processing tasks. Older batteries were unable to handle the power spikes prompting the power management system to perform an emergency shutdown.

The report notes that Apple is also planning to add a “service battery” notice to the battery information tool found in the Settings app under Battery, helping owners diagnose their own hardware.


  • The Stig

    Good that they’re working to address this issue! I did notice some improvement with my iPhone6 since last upgrade, no more sudden 30% drop or unexpected shutdown, but it’s still not holding up in cold weather. Compare to my friend’s phone under the same condition and same model, mine was shutdown unexpectedly when we were just taking a few pictures at a ski hill (-10C). See if I get that “service battery” notice in couple of days.

  • erth

    they are “planning” a service battery notice. this, i believe, is not yet functional. if you have apple care, they will send you a new phone, or you can go to a apple store and they will put in a new battery. i did this and my phone is much better.

  • All I know is the issue was fixed when they replaced my wife battery on her 6s for free.

  • LouisDC

    Same here. I got my battery replaced (for free) at the end of last year and never experienced any unexpected shutdowns since.

  • Dehop

    Same with my 6s. It was shutting down while taking video in cool weather (around freezing) even with 35% remaining. No problem after I got it replaced as part of the free battery replacement program.

  • Kris

    not my iPhone 6. Battery charge drops rapidly in cold. The other day I was shoveling the snow and my iPhone 6 with over 90% charge in my pocket. After an hour of sitting in my pocket in 0 degrees, I saw the battery level drop to under 10%. Also, during regular use, when it reaches close to 30%, the percentage drops suddenly to under 10%, plugging it into charger back and the battery level jumps back to over 30%.

  • Brad Fortin

    “Battery charge drops rapidly in cold.”

    Lithium batteries don’t like the cold, and from the sounds of it you’ve had yours in the cold long enough and often enough to damage the battery.

  • Brenda

    My phone was on the list of those affected so I had it replaced. Haven’t had a problem since so I’m glad I did and would encourage anyone whose phone is on the list to make an appointment with Apple to get the battery changed.
    I keep my phone on an internal (down) coat pocket to protect it from the cold and have never had a problem. Use Siri so I can keep my hands in my pocket too.

  • Larry

    Had my iPhone 6 replaced last May by Apple under my AppleCare plan. It had been shutting down frequently, even when showing 43% charge remaining. I was surprised and pleased – didn’t expect them to replace the complete phone. No problems since.

  • mec

    My iphone 6plus did the same thing.. I live in Vancouver so the temperature isn’t that low compared to other parts of Canada. I went to the genius bar and so called “genius” ran the diagnostics and my phone passed all the tests. she told me not to use the phone outside… that or she said i’d have to pay $90 for a battery replacement and $400 for a refurb phone..this will most likely be my last iphone..