Friday, December 22, 2017

Apple Confirms That It Throttles iPhones With Degraded Batteries

Matthew Panzarino (Hacker News):

Here’s a statement that Apple provided when I inquired about the power profile that people were seeing when testing iPhones with older batteries:

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.

John Gruber:

Prior to adding this feature to iOS last year, iPhones with older declining batteries were shutting down unexpectedly when taxed at peak performance. That’s obviously not good. So now, iPhones with older declining batteries are throttled, when necessary, to keep them running. But now Apple faces accusations that they’re deliberately slowing these devices down to convince people to buy new iPhones.

Jason Koebler:

iFixit teardown engineer Jeff Suovanen performed similar tests with iFixit employees’ phones and shared the data with Motherboard.

Suovanen found that iPhone 6S devices that still had their original batteries (they are about two years old now) had benchmark scores that were up to 57 percent lower than the GeekBench average. Replacing the battery instantly improved the benchmark scores drastically; he saw 70 percent swings in benchmark performance after swapping the old battery for a new one.

“Everyone came back a day later and said, ‘Wow, it works so much faster,’” Suovanen told me on a phone call.


What makes it worse is that Apple does not make it easy to replace the battery yourself, discourages third party repair, and doesn’t have the first party repair infrastructure to handle large numbers of in-store battery swaps, especially in states that don’t have lots of Apple Stores.

Andrei Frumusanu:

Capacity and supply voltage of a battery decreases over time as a function of charge cycles and charging behaviour (Higher charging currents causing more degradation per cycle). This causes the total useable battery capacity before the cut-off voltage to decrease.

The problem facing the iPhones as Apple explains it is however two-fold; the issue at hand happens only during load spikes in which the battery isn’t able to maintain a high enough voltage for the PMIC to reliably be able to use as a source.

SoC blocks such as CPUs and GPUs can have very short transitions from idle to load causing steep transients and load spikes going above the +10W ranges. As batteries degrade over time and the cell impedance also rises also in function of the state of charge and temperature, the current flow becomes restricted and the cell is no longer able to satisfy the power requirement at a high enough operating voltage.


If this is the case then another question rises is if this is indeed just a transient load issue why the power delivery system was not designed sufficiently robust enough to cope with such loads at more advanced levels of battery wear? While cold temperature and advanced battery wear are understandable conditions under which a device might not be able to sustain its normal operating conditions, the state of charge of a battery under otherwise normal conditions should be taken into account during the design of a device (Battery, SoC, PMIC, decoupling capacitors) and its operating tolerances.

If the assumptions above hold true then logically the issue would also be more prevalent in the smaller iPhone as opposed to the iPhone Plus models as the latter’s larger battery capacity would allow for greater discharge rates at a given stable voltage. This explanation might also be one of many factors as to why flagship Android and other devices don’t seem to exhibit this issue, as they come with much larger battery cells.

Jacob Kastrenakes (Hacker News):

There is some good reason for Apple to do this. By their nature, lithium-ion batteries degrade over time, storing less and less of a charge. This happens very quickly on a device we use 24/7. So it's not a bad idea for Apple to limit speeds on older phones, such that they don't push things too far on a depleted battery. That absolutely makes the phone more useable — it apparently helps stop random shutdowns, which are a major pain. And I would think it helps with battery life in general as well.

But it also speaks to a really enormous problem with the iPhone: this $700 to $1,000-plus product, as designed, isn't able to function near its peak after just a year of use. That should be unacceptable.

Slowing down the phone is one way to work against aging issues, but there are other, more obvious things Apple could do here. It could put larger batteries in the iPhone in the first place, so that they last longer before this kind of adjustment needs to kick in.

Some of my thoughts:

Previously: Does iOS Throttle CPUs When Using a Degraded Battery?.

Update (2017-12-22): Rene Ritchie describes additional power management that slows down the CPU separately from the protection during load spikes.

More lawsuits have been filed.

Kirk McElhearn recommends iMazing for checking your battery’s health.

Update (2017-12-23): I already find the iPhone 6–8 thin enough that I need a case to hold them comfortably. I’d much rather carry extra battery than inert plastic.

After the Reddit story broke, an Apple genius told Michael Glenn that iOS does not throttle when the battery is degraded; he was able to fix the performance issues on his iPhone by wiping and restoring it, which got rid of a “rogue system process that somehow persisted through upgrades and restarts” (via John Gruber).

Update (2017-12-28): See also: Accidental Tech Podcast.

Apple has posted a statement.

Update (2018-01-01): Antonio Fonseca:

It seems the SoC team needs to interact more with the battery / engineering team and all of them with the industrial design team. It seems like things are a bit out of sync when it comes to goals for the iPhone project.

Nilay Patel:

Processor speed is just one piece of the battery- and performance-management puzzle, according to Apple: iPhones with older batteries may also more aggressively dim their screens, have lower maximum speaker volumes, and even have their camera flashes disabled when the system needs more peak power than the battery can provide. But other core features, like the cell radio, GPS, and camera quality, aren’t affected, Apple says. The whole approach actually quite clever, but cleverness isn’t a great substitute for speed.

In any event, Apple has a long way to go rebuilding trust with its customers — this story broke well past the tech press and hit TV morning shows and local news with zero nuance about “smoothing instantaneous peaks” and battery chemistry degradation. A lot of people already believed that Apple slowed down their iPhones, and this wave of news was a big data point confirming that for them. It’s going to be a difficult road back.

Ian Spencer:

Key phrase is “whose battery needs to be replaced”. In my experience Apple is loathe to admit a device (iPhone or Mac) has battery problems.

Mitchel Broussard:

In response, iFixit has decided to match that price point and lower the cost of every DIY iPhone battery fix kit to $29 or less.

Rene Ritchie:

No #iPadSlow: Basically, the iPad battery is so big there’s much less concern over power spikes and so Apple hasn’t added them to the same advanced power management system that iPhone 6, iPhone SE, iPhone 6s, and iPhone 7 are on.

dwc1 (via Jon Maddox):

I went to the Genius Bar yesterday and got a walkin appointment for my T-Mobile purchased 6s. The wait time was quoted as 1 hour but took 20 mins. They ran very deep diagnostics to see if I qualify for the $29 offer which I was not expecting since I thought you could just ask for replacement on demand. They told me my battery was working well enough and almost turned me down. I had to press hard that the battery just does not hold the charge long enough anymore. The tech found a workaround by prompting me to sort of claim that the device shuts down unexpectedly on occasion. Once I said yes to shutdown issue that they replaced the battery for FREE. It looks like Apple will be sort of strict about these $29 battery replacements. I also had to leave my phone for the actual repair for about 90 mins wait time while they did the work.

20 Comments RSS · Twitter

They were happy giving people low-power mode with a icon indicating it was active: why not do the same with throttling? Let people know the phone's battery is underperforming for whatever reason and that they can expect the phone to not perform at full performance whilst in the throttled down mode. Ideally there should be away to find out how to avoid the throttled mode: be it charging the battery or replacing it.

"My guess is that Apple’s decisions came from its “we know your needs better than you” philosophy rather than anything this cynical, but it looks bad regardless."

The rest of your points argue pretty persuasively for the "more cynical" option.

As Lukas put it well in a previous thread of yours on the topic: Apple is intentionally acting against the interests of its own users, under the assumption that they're too dumb to notice.

"I’m puzzled by all the people rushing to defend Apple. It’s not that I think Apple purposely did this so people would buy new phones."

The human incentives in all the people rushing to defend Apple don't puzzle me. There's one group of folks who are professionally invested in an "Apple is not Uber" worldview. There's a larger group of folks who have no skin in the game, but would experience unpleasant cognitive dissonance in seeing Apple as predatory and sleazy.

Even you're rushing to defend Apple, Michael! You're just more intellectually honest than most, so you lay out a compellingly damning case at the same time you're uncomfortable in reaching the obvious conclusions.

I mean, the positive case for Apple here is essentially the pretty strained:

They didn't purposely do this so people would buy new phones. They did this out of extreme carelessness and laziness, making a string of decisions that all functionally led to incentivizing people to buy new phones, but they never quite realized their decisions would have the effect of making them more profit, even though making more profit is essentially their job description.

The good news here is that Apple still isn't Uber! The breaches of trust that Uber practices are far more fundamental than what Apple does. But this isn't some wildly unusual behavior for Apple either. Strategies for inducing planned obsolescence / speeding up the replacement buying cycle are a core part of what Cupertino thinks about and bases decisions upon. This one just looks worse than normal when exposed to sunlight, and will have reputational cost.

"Spontaneous shutdowns have occurred at least as far back as the iPhone 5s"

Don't hesitate to add iPhone 5.

A Victim

@Chucky The “obvious conclusion” would require them thinking they could keep it secret and/or avoid much reputational cost, and neither seems likely to me.

I think the positive case is that they just really like thin designs and prioritize that. It’s unquestioned. They didn’t realize the extent of the problem until they added more analytics about a year ago, then got the results over the next few months, at which point if they were going to make major hardware changes it would be for iPhone 8 or later. They tried to paper over it with the software fix, then when customers figured out what was happening they botched the response.

[…] Michael Tsai’s Roundup of Articles Related to Apple’s Throttling of iPhones With Degraded Batter… […]

"The “obvious conclusion” would require them thinking they could keep it secret and/or avoid much reputational cost, and neither seems likely to me."

Yup. No matter what anyone thinks Apple was consciously doing, we can all agree this was a massively botched strategy.

"I think the positive case is that they just really like thin designs and prioritize that. It’s unquestioned."

See, this is the broader point I was trying to touch upon. Why do they "really like thin designs"? Do we think that after years of pursuing thin designs as the Prime Directive, it hasn't occurred to all Cupertino decision makers that thin designs are a handy way to force planned obsolescence, accelerate the replacement cycle, and increase profits? Do really we really think this is just coincidental to Jony Ive's aesthetic taste, and not an intentional business strategy?

The real question in trying to sort out the motivation behind "thin design" is examining to what degree Apple's interests align with its customers' interests. I think this alignment was quite strong a decade ago, and it's far, far weaker today.

To cite an individual example, when Apple rolled out the MacBook Air, it was producing thin design in alignment with its customers interests. For some folks, a MBA was perfect! It had a shorter lifespan, but it was more convenient for certain use cases. For others, a MBP was perfect! Now, you can only buy a MBA. Why is that? I'd propose that a decade ago, Apple saw a broad strategic financial incentive in aligning with its customers' interests in a way that it doesn't today.

In the example of iPhone CPU throttling, determining whether or not Apple did this in its customers interests or not is at the core of how people react to this, even while everyone agree they botched whatever they meant to do. Their degree of alignment with their customers is the question that determines if folks think this episode has any broader meaning.

In short, I fully agree with your analysis of the "positive" case for Apple here. But I see "thin design" as non-explanatory: a hint of the actual problem, not the problem itself.

@Chucky It could be as simple as having many years of success pursuing thin, plus “Jony says.” In 2008 it was inconceivable that a MacBook Air would be enough for everyone, so the choice was forced on them. Anyway, I don’t think we on the outside have enough information to get a satisfactory explanation. Thomas Brand is less charitable.

Regardless of Apple's motivation(s) or when they originally identified this hardware issue, their response is what matters. Apple *could have* issued a recall or replacement program to address this hardware issue. Instead, they *deliberately chose* to decrease the performance of already-purchased hardware in a way that kept customers from knowing there was a hardware issue in the first place.

Remember when Intel recalled the initial release of their Sandy Bridge chipsets because the SATA ports could degrade or fail over time in unusual environmental conditions? That was a big financial cost for them (Intel set aside $700 million), but ultimately it didn't hurt their reputation much because of the perception that they tried to get out ahead of the problem as much as possible. Imagine if instead of a recall, Intel decided to deliberately/remotely/silently slow down the SATA bus after people bought their PCs, and then only acknowledge they did this after being called out on it, all while claiming that this course of action was in the best interest of customers...

I'm sorry, the unofficial Apple PR team that masquerades as tech press, when at best they represent sheer partisan punditry, should be especially ashamed of themselves....again.

I've read many of these people over the years and even enjoyed their writings, but sometimes they have to step out of the Cupertino bubble and actually understand how technology and people interact. "My phone is super slow and Apple won't replace it under warranty until if fails a test, and even better, refuses to even let you pay them to replace it," is simply not consumer friendly.

This was a stupid, unnecessarily manufactured controversy that Apple alone created. Apple just plain refused to communicate. They reign from on high and use their tech heralds to disseminate their pronouncements instead of getting down and dirty with their actual customers.

"Regardless of Apple's motivation(s) or when they originally identified this hardware issue, their response is what matters ... Remember when Intel recalled the initial release of their Sandy Bridge chipsets..."

I think that's a bad analogy.

This isn't a "hardware issue". This is an engineering trade-off decision. Recalling iPhones wouldn't change the way batteries age or the resulting implications.

And while the plaintext "scandal" is that Apple didn't tell folks what was going on, Apple's motivation is the true issue, even though I agree with Michael that we're not likely to discover what that motivation was. There's a vast difference between negligently sloppy communication and predatory corporate behavior.

>it hasn't occurred to all Cupertino decision makers that thin designs
>are a handy way to force planned obsolescence, accelerate the replacement
>cycle, and increase profits?

Given what we know, it's very difficult not to at least consider this explanation to be a very plausible one.

Any time there is any kind of survey of iPhone users, battery problems are at or near the top spot for complaints. "It's too thick" never even shows up. Clearly, the majority of iPhone users would be happy to give up a bit of the device's thinness in order to gain some additional battery capacity. Yet Apple refuses to do just that, and keeps battery capacity at a constant "just barely (but maybe not really) adequate" level.

At some point, you just have to wonder why that is, and the "Jony just really really really loves thin devices" explanation is starting to smell a little bit fishy.

Also, there remains the thing about just how brazenly incompetently Apple has behaved here. Even if we assume benign intent on everybody's part, just how incredibly stupid do you have to be to deal with constant conspiracy theories about planned obsolescence, only to secretly introduce a feature that looks exactly like planned obsolescence, and has a pretty much 100% probability of being discovered immediately. Just what in the world was going through these people's minds when they made that decision. Was there really nobody in those meeting rooms who was like, hey, guys, about that thing you are planning... You do realize that this is going to totally blow up in our faces, right? Not to mention that it's totally unethical to do this without telling our users?

My iPhone SE battery is at 86% original capacity, and I’ve noticed slow down. Just ran geek bench and, sure enough, the scores are way down - about 25% lower than the standard se score.

Interestingly, gpu compute scores aren’t affected (or only very slightly). I very rarely play games, so don’t know how much impact the battery problem is causing there for sure, but I guess games will be hit hardest by this new limiter.

This is going to be a real issue for apple - every claim about having the fastest cpu is going to be followed (in reviews and in peoples’ minds) by a reminder that fast cpus will become slow quite soon. For what it’s worth, I’d like a larger battery and consistent performance, but I like the se size and i’ll probably get it again if they update it...

Hi Michael.
This situation is baffling, not just because Apple did something consumers don't like, but because their reasoning is too opaque for even domain experts like you and Chucky to agree!

The other baffling thing consumers need to cope with is re-evaluating the real cost of owning an iPhone. I know I'm busy doing back of the envelope calculations right now, and I'm not feeling a whole lot of confidence in the results. Is it 500 cycles Apple claims to get to 80% to trigger a battery replacement? Macworld thinks its only 400. But they also think 400 cycles = 13 months of full time use, but more likely 24 months. (But not 26 months?) At two years, AppleCare expires, so save $130 up front, spend $80 later? So a $450 6s + $80 = $530, but is that amortized over two years, or do we assume four, since the replacement battery is probably good for two years. Maybe?

Anyway, I was just talking to a pretty mainstream, non technical person, a small business owner, and they already know about the battery capacity thing. And they think $80 is pretty expensive for a fix. Yeah, $79, but that isn't fooling anyone who calculates sales tax in their head 10 hrs/day.

People like predictability, stability, reliability. Does Apple still have a reputation for that?

>This isn't a "hardware issue". This is an engineering trade-off decision.

Isn't it... both? An engineering tradeoff that directly led to a hardware issue?

Short of a revealing email or expert testimony to demonstrate that they knew this would happen, I doubt a court would hold Apple liable for making an engineering tradeoff. But a deliberate choice to 'fix' the issue in a way that keeps customers from knowing the issue exists? I think a judge might very well hold Apple accountable for that because there's no need for speculation in this approach. Apple's already admitted they degrade performance to keep the hardware issue from surfacing, and they didn't tell customers about it until third parties and the media revealed this behavior.

>Recalling iPhones wouldn't change the way batteries age or the resulting implications.

Is this the case? Does a phone with X battery capacity and Y peak power consumption have the potential to exhibit this issue when operating below Z air temperature, regardless of the quality of other power-delivery components? I don't know the answer, but it still seems to be an open question, right?

If an iPhone is experiencing this throttle issue because of a degraded battery, does the phone experience this issue when it's plugged to an unlimited power source?

@stephane Yes. But I’ve heard conflicting reports on whether the throttling only happens when the battery is charging.

[…] Previously: Apple Confirms That It Throttles iPhones With Degraded Batteries. […]

[…] is how today’s Apple handles hardware design defects, from bending phones to batteries, desktop and laptop keyboards, and 2013 Mac Pro thermal failures. You might expect, based on the […]

[…] interesting, compared with the “a very small number” that Apple used in discussing the iPhone battery issues, and because on Twitter, at least, it seems like the percentage is not […]

[…] Previously: Apple Confirms That It Throttles iPhones With Degraded Batteries. […]

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