iPhone Slow: What you need to know

iPhone 6s Plus
iPhone 6s Plus (Image credit: iMore)

Apple has published a letter explaining the confusion caused by the iOS 10.2.1 update last year that prioritized battery health over peak performance. The company is also offering deep discounts on battery replacements, down from $79 to $29, and has issued a software update that provides far more insight for customers into the state of their battery health. Most recently, Apple has offered a $50 credit to those who replaced their iPhone batteries before the discount program took affect. Here's what you need to know.

January 14, 2018: Apple replaced 11 million batteries — 5x to 10x normal — as part of the discount program

John Gruber, writing for Daring Fireball:

During Apple's all-hands meeting January 3, Tim Cook said Apple replaced 11 million batteries under the $29 replacement program, and they'd have only anticipated about 1-2 million battery replacements normally.

For much of last year, Apple Retail was packed with people waiting to get battery replacements. Anyone who visited the stores with any regularity, or who had even a passing familiarity with Apple Retail itself could easily see how the influx of people could not only become a new small business itself, but in hindsight, following Tim Cook's previous comments, a significant factor in slowing upgrades beyond China.

But, it's great John could put a number to the wide range of assumptions.

January 2, 2018: Tim Cook: Battery replacements impacted iPhone upgrades in Q1 2019

Looks like there was a cost to the battery upgrade program beyond just the parts and the labor. From Tim Cook:

we believe there are other factors broadly impacting our iPhone performance, including consumers adapting to a world with fewer carrier subsidies, US dollar strength-related price increases, and some customers taking advantage of significantly reduced pricing for iPhone battery replacements.

Cook had previously addressed the issue during Apple's Q1 2018 conference call:

On the battery, Toni, we did not consider in any way, shape, or form what it would do to upgrade rates. We did it because we thought it was the right thing to do for our customers and I, sitting here today, I don't know what effect it will have. And again, it was not in our thought process of deciding to do what we've done.

October 31, 2018: iPhone 8, iPhone 8 Plus, iPhone X join power management program with iOS 12.1

Apple has updated its knowledge base article, adding last year's iPhone 8, iPhone 8 Plus, and iPhone X to the list of devices that, as of iOS 12.1, are included in Apple's performance management system, which tries to maintain battery longevity and prevent unintended shut downs due to spikes in power demand, by throttling down the speeds, where and when necessary.

But, due to iPhone 8, iPhone 8 Plus, and iPhone X's more advanced power management systems to begin with, Apple says it's less likely anyone will notice.

From Apple.com:

Starting with iOS 12.1, iPhone 8, iPhone 8 Plus, and iPhone X include this feature, but performance management may be less noticeable due to their more advanced hardware and software design.

As always, if you hate the very idea of performance management, you can keep it off in Settings > Battery. Not adding last year's iPhones, given how lithium ion batteries age, especiallly prematurely if they're exposed to excessive heat or other damage, would have been irresponsible, so whether you use it or not, be glad it's there.

May 23, 2018: Apple offering $50 credit for out-of-warranty iPhone battery replacements

Apple is offering a $50 credit to people who paid for an out-of-warranty battery replacement for iPhone 6 or later. The replacement had to have been done between January 1, 2017 and December 28, 2017, and completed at an Apple Store, Apple Repair Center, or an Apple Authorized Service Provider.

From Apple:

The credit will be provided as an electronic funds transfer or a credit on the credit card used to pay for the battery replacement service.Eligible customers will be contacted by Apple via email between May 23, 2018 and July 27, 2018 with instructions on how to obtain the credit.If you have not received an email from Apple by August 1, 2018, but believe you are eligible for a credit based on the terms above, please contact Apple by December 31, 2018. Note that proof of service at an Apple authorized service location may be required.

So, if this applies to you, sit tight and wait for your email.

May 9, 2018: iPhone replacement batteries no longer facing shortages

MacRumors:

Apple Stores and Apple Authorized Service Providers can now order iPhone replacement batteries from Apple and receive them without facing extended shipping delays, but that doesn't necessarily mean that every Apple Store or authorized repair shop will have supply available right away.

Good news. If you've been waiting to have your iPhone battery serviced under the replacement plan, you shouldn't be waiting much longer.

March 29, 2018: iOS 11.3 now available with Battery Health

With iOS 11.3, Apple has delivered on its promise to surface battery health information for iPhone users whose devices are subjected to advanced performance management. The new panels, available in Settings > Battery, show current maximum capacity and peak performance capability, and will also inform you if your iPhone is being slowed down, whether it needs service, and will even allow you to turn off advanced power management — now called performance management — if you so choose.

If your iPhone SE, iPhone 6, iPhone 6s, or iPhone 7 had been slowed down due to prevent an unexpected shutdown, iOS 11.3 will restore it to its previous, unmanaged performance levels. Performance management will only kick back in when and if you experience another unexpected shutdown. Until then, it's a clean slate.

Peak performance capability is the ability of your iPhone's battery to supply adequate charge even in the face of highly demanding tasks, up to and including those that cause power spikes.

You can disable performance management in settings as well, though you risk unexpected shutdowns if you do so.

March 1, 2018: Apple testifies about 'iPhone slow' before Canadian Parliamentary Committee

John Poole, the Ontario resident who runs Primate Labs, the makers of Geekbench, and Apple Canada were brought in to testify today in front of a House of Commons committee looking into the recent controversy surrounding iPhone battery throttling.

While the iPhone sold in Canada is identical to iPhones sold in other parts of the world, and iOS on iPhones in Canada is identical to iOS on other iPhones running in other parts of the world, some members of parliament wanted to be seen doing their part for queen and country. And, since battery throttling kicks in when batteries are old or cold — and Canadians not only face extremely cold winter weather but sometimes also prematurely age their iPhones by mounting them in front of heating vents in the cars or leave them on top of heating elements in their homes, we can benefit from the additional exposure and education.

Based on early reports, it sounds like Poole's testimony was substantially in line with what he discussed on the Vector podcast when the story first started breaking.

Apple Canada's statement, issued by Jacqueline Famulak, Manager of Legal and Government Affairs at Apple Canada, was also directly in line with previous statements from Apple in the U.S. and Apple's CEO, Tim Cook.

Apple Canada Inc. is a sales and distribution entity. We also have 29 retail stores across Canada. The design, manufacture and testing of devices has always been done by Apple Canada's parent company, Apple Inc. ("Apple") which is based in California.I'm here to help the Standing Committee understand the facts of Apple's efforts to make sure that users of Apple devices get all the benefits from the devices they use, and that these benefits last as long as possible, even in a world of rapid innovation.Apple Inc. has recently answered a series of questions posed by the chairs of the United States Senate Committee on Commerce, Science and Transportation, and of the United States House of Representatives Committee on Energy and Commerce. Apple's comprehensive answers to those questions are attached to my written statement.I am here today to answer your questions, but before doing so, I would like to share a few important points at the outset about Apple's actions regarding iPhone batteries and performance and what the Canadian consumer may have experienced as a result of those actions.First, Apple would never intentionally do anything to shorten the life of any Apple product or degrade the user experience in order to drive customer upgrades. Apple's entire philosophy and ethic is built around the goal of delivering cutting-edge devices that our customers love. Our motivation is always the user.Second, Apple's actions related to performance of iPhones with older batteries were designed specifically to prevent some older models from unexpectedly shutting down under certain circumstances. And we communicated this publicly. Let me explain.In order for a phone to function properly, the electronics must be able to draw power from the battery instantaneously. But, as lithium-ion batteries age, their ability to hold a charge diminishes, and their ability to provide power to the device decreases. Very cold temperatures can also negatively affect a battery's performance. A battery with a low state of charge may also cause the device to behave differently. These things are characteristics of battery chemistry that are common to lithium-ion batteries used in all smartphones, not just Apple's.If power demands cannot be met, the iPhone is designed to shut down automatically in order to protect the device's electronics from low voltage.We do not want our customers to experience interruptions in the use of their iPhones, whether that is making an emergency phone call, taking a picture, sharing a post, or watching the final minutes of a movie. To address the issue of unexpected shutdowns, we developed software that dynamically manages power usage when, and only when, an iPhone is facing the risk of an unexpected shutdown. This power management software helps keep iPhones on when they otherwise might turn off – it does this by balancing the demand for power with the available supply of power.The sole purpose of the software update in this case was to help customers to continue to use older iPhones with aging batteries without shutdowns – not to drive them to buy newer devices.Third, Apple regularly provides software updates for iPhone and our other devices. These software updates can include everything from new features, to bug fixes, to security updates. Whenever we issue a software update, we include a ReadMe note which has a description of the contents of the update for the customer to review prior to the software installation. In the case of iOS 10.2.1, we stated that it "improves power management during peak workloads to avoid unexpected shutdowns on iPhone."Those things said, our intention has been to give our customers the best products and the best experiences possible. We take our customer concerns seriously and have taken a number of steps to address them.First, Apple is offering to provide out-of-warranty replacement batteries for $35 instead of the original price of $99, to anyone with an iPhone 6 or later whether they have experienced any performance issues or not. This offer began on December 28, 2017, and is available through to the end of December 2018, so customers have plenty of time to take advantage of it.Further, Apple is also providing customers with additional information on its website about iPhone batteries and performance including tips to maximize battery performance.In addition, iOS 11.3, which is now in public beta, will add new features to give customers easy access to information about the health of their iPhone's battery. Available this spring, the new software will offer power management which will recommend if a battery needs to be serviced. It will also allow customers to see whether the power management is on, and they can choose to turn it off if they wish.

It's hard to parse how much politicians care about consumers versus how much they care about the spotlight. Hopefully, in this case, the members of parliament are doing their jobs, educating themselves, and working towards policies that truly benefit Canadians, not just news cycles.

January 31, 2018: Apple: iOS 11.3 battery feature update going into beta next month, release this spring

Apple and Tim Cook previously said iOS 11.3 would include new battery features, including information on battery health, notification for batteries that need servicing, and even a way to toggle off the advanced power management that reduces performance on iPhones with degraded batteries to prevent them from shutting down.

In a statement from Apple today, the company let me and other outlets know that those features will first appear in beta next month and in the release version of iOS 11.3 this spring.

"About a year ago, we delivered a software update that improves power management during peak workloads to avoid unexpected shutdowns on certain iPhones with older batteries," an Apple spokesperson told iMore. "We know that iPhones have become an important part of the daily lives of our customers and our intention was to improve the customer experience."We sought to further improve the customer experience in December by announcing a significant discount on replacement batteries for certain iPhones. We also announced that we began developing a new iOS feature to show battery health and which would recommend when the user should consider replacing their battery. These actions were taken to further assist our customers and help extend the life of their iPhones. In addition, users will be able to see if the power management feature is being used to prevent unexpected shutdowns, and turn it off if they so choose. These features will be included in a developer release next month and a user release this Spring."As we told our customers in December, we have never — and would never — do anything to intentionally shorten the life of any Apple product, or degrade the user experience to drive customer upgrades. Our goal has always been to create products that our customers love. Making iPhones last as long as possible is an important part of that.

And, with regards to the investigations reported yesterday (see below):

" We have received questions from some government agencies and we are responding to them."

January 30, 2018: DOJ and FEC reportedly looking into iPhone power management

The United States Department of Justice (DOJ) and the United States Securities and Exchange Commission (SEC) are looking into how Apple handled disclosing the advanced power management (and related performance throttling) introduced in iOS 10.2.1.

From Bloomberg:

The government has requested information from the company, according to the people, who asked not to be named because the probe is private. The inquiry is in early stages, they cautioned, and it's too soon to conclude any enforcement will follow. Investigators are looking into public statements made by Apple on the situation, they added.

Apple included the following in the release notes of iOS 10.2.1:

It also improves power management during peak workloads to avoid unexpected shutdowns on iPhone.

At the time, Apple also briefed iMore, TechCrunch, and possibly other outlets about the reasons for fix.

Again, from Bloomberg:

While the slowdown has frustrated consumers, U.S. investigators are concerned that the company may have misled investors about the performance of older phones.

Investors really only care about making more money. So, "performance of old iPhones", in this context, likely means, "how the changes could potentially negatively impact the stock price."

January 18, 2017: Apple will let users disable performance throttling introduced last year to prevent unexpected shutdowns

Apple CEO, Tim Cook, has stated that an upcoming iOS software update will let users turn off the advanced power management that prevents unexpected shutdowns by throttling the processor. But they shouldn't.

Speaking to ABC News (transcript via MacRumors):

We're also going to... first in a developer release that happens next month, we're going to give people the visibility of the health of their battery. So it's very, very transparent. This hasn't been done before, but we've thought through this whole thing and learned everything we can learn from it.So we want to do that, and in the situation... and we will tell someone we're reducing your performance by some amount in order to not have an unexpected restart. And if you don't want it, you can turn it off. Now we don't recommend it, because we think people's iPhones are really important to them, and you never can tell when something is so urgent. Our actions were all in service of the user. I can't stress that enough.

When people first became upset about the advanced power management in iOS 10.3.1, I suggested Apple should have let the phones shut down once and then, immediately on reboot, offered a button to enable advanced power management to prevent it happening again. That way, I reasoned, people would better understand the problem and that Apple was trying to help extend the useful life of the devices. This is like that but in reverse.

As Cook said, I don't think anyone should disable it. I don't recommend anyone disable it. I don't think anyone who understands why Apple implemented it will even want to disable it. But for those with very specific needs and circumstances, or for whom it's never really been about understanding, the switch will be there.

Cook also said Apple explained what it was doing at the time but that many people probably weren't paying attention and that Apple could have done a better job explaining what was happening and why.

As someone who had the 10.3.2 changes explained to him by Apple at the time, I think it's clear "advanced power management" didn't equate to "performance throttling" in people's minds, regardless of how obvious it might seem in hindsight.

I'd also guess even Apple didn't imagine how noticeable the throttling would become for people with older batteries in extremely poor health.

Apple hasn't said precisely which iOS update will include the new battery health features and advanced power management switch, though iOS 11.3 seems like a likely candidate. Look for it in beta next month and release towards the end of the quarter.

December 30, 2017: Forget mid–January, Apple starting discounted battery replacements now.

"We expected to need more time to be ready," an Apple spokesperson told iMore. "But we are happy to offer our customers the lower pricing right away. Initial supplies of some replacement batteries may be limited."

What you need to know about Apple's $29 battery replacement program

From Apple:

We've been hearing feedback from our customers about the way we handle performance for iPhones with older batteries and how we have communicated that process. We know that some of you feel Apple has let you down. We apologize. There's been a lot of misunderstanding about this issue, so we would like to clarify and let you know about some changes we're making.First and foremost, we have never — and would never — do anything to intentionally shorten the life of any Apple product, or degrade the user experience to drive customer upgrades. Our goal has always been to create products that our customers love, and making iPhones last as long as possible is an important part of that.

Specifically, here's what Apple's doing:

To address our customers' concerns, to recognize their loyalty and to regain the trust of anyone who may have doubted Apple's intentions, we've decided to take the following steps:

  • Apple is reducing the price of an out-of-warranty iPhone battery replacement by $50 — from $79 to $29 — for anyone with an iPhone 6 or later whose battery needs to be replaced, starting in late January and available worldwide through December 2018. Details will be provided soon on apple.com.
  • Early in 2018, we will issue an iOS software update with new features that give users more visibility into the health of their iPhone's battery, so they can see for themselves if its condition is affecting performance.

As always, our team is working on ways to make the user experience even better, including improving how we manage performance and avoid unexpected shutdowns as batteries age.

At Apple, our customers' trust means everything to us. We will never stop working to earn and maintain it. We are able to do the work we love only because of your faith and support — and we will never forget that or take it for granted.

Simultaneously, Apple has published a tech support article that explains in far greater detail what happens with lithium-ion batteries in modern devices like iPhone.

From Apple Support:

Our intention for iPhone is to deliver an experience that is simple and easy to use. Doing so requires a lot of engineering and many advanced technologies. One important technology area is battery and performance. Batteries are a complex technology, and there are a number of variables that contribute to battery performance and related iPhone performance. All rechargeable batteries are consumables and have a limited lifespan—eventually their capacity and performance decline so that they need to be serviced or recycled. As this happens, it can contribute to changes in iPhone performance. We created this information for those who would like to learn more.

Overall, this is the right move from Apple after a series of missteps: It offers clarity on the issue, communication on why it happened, and explanation of how the company will fix it.

We're still digging into everything, and will update again with more information and further analysis ASAP.

The Genesis of "#iPhoneSlow"

How did #iPhoneSlow become an issue? It starts with a simple problem: Aging lithium-ion batteries. It's been two years since iPhone 6s shipped, and three years since iPhone 6.

Two to three years can be a long time for batteries, as we've seen from these Reddit comments:

My iPhone 6S has been very slow these past few weeks, and even after updating multiple times, it was still slow. Couldn't figure out why, but just thought that iOS 11 was still awful to me. Then I used my brother's iPhone 6 Plus and his was... faster than mine? This is when I knew something was wrong. So, I did some research, and decided to replace my battery. Wear level was somewhere around 20% on my old battery. I did a Geekbench score, and found I was getting 1466 Single and 2512 Multi. This did not change wether I had low power mode on or off. After changing my battery, I did another test to check if it was just a placebo. Nope. 2526 Single and 4456 Multi. From what I can tell, Apple slows down phones when their battery gets too low, so you can still have a full days charge.

Once upon a time, you loaded a web page or downloaded an email then spent a few minutes reading, turned off your iPhone, and went back to your day. Now, we have social and gaming apps that keep the screen on while checking GPS, downloading media, showing the camera's live view, and layering on augmented reality near-constantly. The tech industry has been prioritizing power efficiency over performance for years: Processors could always run at redline, but they'd burn the battery out just as fast.

Balancing power and performance is key, and Apple has been addressing this in multiple ways — like systems-on-a-chip with both high-efficiency and high-performance cores, and machine-learning-based power management.

But lithium-ion batteries are lithium-ion batteries. When it comes to older phones or those with poor battery health, Apple begun prioritizing battery life over processor speed in iOS 10.2.1. Here's what Apple told me at the time:

"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."

That caused a hit to the phone's performance, but now allowed older iPhone models to last longer throughout the day and keep them from unexpected shutdowns. Here's what I wrote at the time:

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 10.2.1. 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.

But Apple's power management may have been too overly aggressive (or the "battery service" notice in Settings was overly passive). Between Reddit threads and Geekbench tests, a number of users experienced Apple's ramped-up power management without seeing the explanation or understanding why.

After complaints, Apple initially provided iMore with the following statement:

"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 company has now put a firmer hand on things, rolling out a low-cost battery replacement program and apologizing for the issue. It's in Apple's best interests to keep customers happy so that they remain customers. Likewise, everyone at Apple has friends and family with older iPhones, and I've never gotten anything from anyone there other than a profound desire to keep those iPhones running as well as possible for as long as possible.

Apple would certainly be accused of maleficence either way: If it doesn't provide updates, it's withholding features. If it does, it's overloading. If it prioritizes performance, it's letting old phones die. If it prioritizes battery life, it's slowing them down. It's Apple's job to provide the best balance it can for as many customers as it can, though, and to take any all accusations that come along with it.

Rene Ritchie
Contributor

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.