Apple and iOS 10.2.1 address unexpected shutdowns on iPhone 6, iPhone 6s

iPhone 6 and 6S
iPhone 6 and 6S (Image credit: iMore)

For a while now there have been reports of some older iPhone models, namely iPhone 6 and iPhone 6s, shutting down unexpectedly. Apple introduced some diagnostics into iOS 10.2 back in December to try and determine what was happening and, with iOS 10.2.1, they've rolled out a fix.

"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," Apple told iMore. "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." 

My understanding is that, if a particularly processor-intensive task, such as a complex photo filter, caused a significant spike in power demand, an older battery unable to meet that demand could prompt a shutdown. So, by improving the advanced battery management in iOS 10.2.1, Apple has reduced the likelihood of that happening.

Batteries do age with time and charge cycles, though. To help with awareness, Apple is adding a service notice to Settings > Battery in iOS 2.1. It's similar to the one already in place on the Mac. Anyone with a particularly weak battery who still experiences the issue should contact AppleCare.

You can also take steps to prevent your battery from aging prematurely. Apple offers a set of battery best practices (opens in new tab) available.

In general, though, Lithium Ion doesn't like getting too hot or too cold. Don't leave your iPhone on your car's dash board or beneath the hot sun in summer, or in a mount nf front of a hot car vent in winter. Likewise, don't leave it out in the ice and snow.

Technical elements aside, I like how Apple solved for this. Phones are complex, but Apple controls the whole widget from atom to bit to pixel. Getting new diagnostics into a previous update, collecting data, figuring out the problem, and then rolling out the solution in a subsequent beta isn't just clever, it's smart.

You can criticize how long troubleshooting sometimes takes or how Apple almost never communicates during the process, but the "measure as many times as needed, cut once" approach has so far produced good results. It's also one of the primary reasons I use an iPhone. No janky outsourced support, no carriers getting in the way of updates, just issues getting fixed.

If you were experiencing the shutdowns on iPhone 6 or iPhone 6s, let me know how iOS 10.2.1 worked for you!

Rene Ritchie

Rene Ritchie is one of the most respected Apple analysts in the business, reaching a combined audience of over 40 million readers a month. His YouTube channel, Vector, has over 90 thousand subscribers and 14 million views and his podcasts, including Debug, have been downloaded over 20 million times. He also regularly co-hosts MacBreak Weekly for the TWiT network and co-hosted CES Live! and Talk Mobile. Based in Montreal, Rene is a former director of product marketing, web developer, and graphic designer. He's authored several books and appeared on numerous television and radio segments to discuss Apple and the technology industry. When not working, he likes to cook, grapple, and spend time with his friends and family.

  • "Technical elements aside, I like how Apple solved for this." The rollout and adoption of updates on iOS devices is quite brilliant, but the glacial pace that has led up to it is not. The Apple support pages have been littered with reports of the battery issue since Sept 2015, and now nearly 18 months and a couple of class action law suits later they've issued a fix. Apple should be held to task for this, not applauded.
  • Please don't tell me you’re surprised?
  • the funny thing is that they didn't fix the issue just mitigated it for a majority of users. it looks like apple made some crappy design choices for the 6 and 6s and now it's biting them in the ***
  • I agree, this is a hardware issue and no software "fix" will eventually resolve the core issue. That's why I suggest everyone make an appointment wit Genius Bar and get their batteries replaced. I know I did. After I am done with my 6S and hand it down to one of my family member, at least I know they have a fresh battery
  • The issue certainly wasn't due to heavy tasking. My work phone is an iPhone 6 and I only use it as a phone in emergency situations, nothing else and I have had this happen a couple times. No idea yet if it's improved with this latest update but here's hoping it's finally put to bed after this many years. Posted via the iMore App for Android
  • Surely the best Apple phones to date would be the 7 and 7 plus? They're more powerful, the iPhone 7 Plus has the dual-lens, dual stereo speakers, the new home button means that they will no longer break so easily, among all the other improvements
  • The 7 Plus is indeed a great phone, but the 7's battery life is appalling in comparison to the 6S.
  • Strange. I hear the opposite. The 6s, on the other hand, is known to have even worse battery life than the 6 that came before it.
  • I'm just speaking from personal experience. With the 6S I could easily manage a day with average usage, with the 7 that replaced it I'd need to recharge by early evening.
  • You're LITERALLY the only person who is still complaining about "no 3.5mm jack" being an issue, despite the fact that the phone comes with an adapter _in the box_ and also comes with Lightning headphones. Battery life is definitely not worse, both me and my friend have iPhone 7 Plus's and can both attest to the fact that it has improved from the 6 Plus. There's no "etc", you wrote that because you couldn't think of anything else. Sorry Steve… er… TROLL!
  • René Jr you so bottom hurt! Just because someone has a different opinion to you! You think the iPhone 7 is great then that's fine, Steve thinks thier iPhone 6s is the best guess what ? That's fine too :-)
  • Either an alt account or one of Steve's 3 friends… Steve doesn't have an "opinion", he just likes to troll
  • I don't know anyone who needs to use both at the same, if this is a problem you're in the very small minority who have complained about this issue because you're the first person I've heard to say this. Why do you need both at the same time?
  • 6's also have the issue. Some apple support forums also mention ip5 having a few similar issues as well. Posted via the iMore App for Android
  • I'm assuming my daughter's iPhone 6s is fixed by the battery recall swap she just had done. Clearly the batteries in the early run 6s's were faulty. I was happy Apple fixed it w/o issue for us. I'm a recent convert and while the transition has been frustrating at times, it is things like this that remind me it made the right call by switching.
  • iOS 10.2.1 has been out for a couple of weeks now. I don't see this "about" section in the Battery section under Settings. And yes, my iPhone 6S Plus did face a random shutdown in iOS 10.2.1 where plugging in was necessary to get it to boot up again. Got this 6S Plus in December 2015 and it has less than 110 charge cycles on it and the battery health is already at 90-92% overall capacity, which is poor. My almost 2 and a half year old iPhone 6 is at 96% battery health capacity and it has a lot more than 100 charge cycles, maybe even double. Or is this a special build of iOS 10.2.1 which can be obtained manually via iTunes or from services like IPSW(dot)me ?