Why Apple slows down the iPhone with aging batteries |igeneration

After several days of doubts and controversy, Apple confirmed to slow down certain iPhone models with aging batteries."Last year", explains the company's press release, "we added to the iPhone 6, iPhone 6s, and iPhone a functionality smoothing brutal peaks when necessary […].We extended this feature to the iPhone 7 with iOS 11.2, and plan to do so with other products in the future." What's the point ?

An old battery is a lazy battery

"Lithium-ion batteries more difficult to provide their maximum current in low temperature, low load or aging conditions," explains Apple.This is a question of internal resistance, which increases with the drop in temperature, with the reduction in load, and with the repetition of the (dice)) cycles.The measurement of internal resistance is a good indicator of the aging of a battery, which becomes less and less capable of responding to the requests of electronic components.

Pushed into her last entrenchments, she can even be dangerous.Dendrites, small peaks of metallic lithium which gradually "grow" on the anode, can end up provoking damage and short-circuits.These problems are inherent in the chemistry of lithium-ion batteries, but are exacerbated by the uses of smartphones, which put the batteries to the test.

Lithium-ion batteries bear it quite difficult to be fully loaded and unloaded, hate cold, and do not like excessive heat more.A literally explosive cocktail ... However, you load your iPhone every night, with an induction charger that heats up or an ultra -fast charger that burns, use it in snow as on sand, to play games using all the power of the processorsand mobile graphics chips.

You always ask your phone more, but the chemistry of lithium-ion batteries has not fundamentally changed for 25 years, even if it has progressed a lot.Worse: Instead of changing your device before the battery reaches 800 or 1,000 cycles and these problems are inevitable, you now tend to keep it longer, then resell or pass it on to your loved ones.

The software protects you from batteries and protects the batteries

This is why all manufacturers multiply software tips to protect you from batteries ... and protect the batteries.The most famous example is undoubtedly that of the battery level indicator: "100 %" does not indicate a full battery (but rather an almost full battery, the end of the recharge requiring a very specific procedure and very verylong)), "0 %" does not indicate an empty battery (but an almost empty battery, the controller having to remain powered while you find a socket)).

Worse: all figures between these two terminals are only an approximation, based on average consumption relating to the theoretical capacity of the battery.Launch an intensive operation and the level will melt as snow in the sun, but stabilize or even go up in stride, because the system has surreated.(The withdrawal of the macos hourly indicator, which never existed on iOS, was not vain or unjustified.))

With the aging of the battery, the estimate will be less and less precise, which explains that iPhone can be extinguished suddenly at 20 %.The system believes that there are 20 % of the battery, but is wrong because it no longer knows the specific characteristics.This is why it is recommended to regularly calibrate the battery: by observing its discharge then its recharge, the system can calculate its true capacity.

These estimates are all the more difficult since the characteristics of each battery are very slightly different at the exit of the factory, much more after a few weeks of use, a variability that an algorithm can foresee but not completely resolve.Add the possibility that the characteristics of a batch of batteries are extraordinary, and you get the situation that motivated the replacement program for the battery of the iPhone 6S.

A communication problem ...

The battery indicator is a lie, but of these pious lies that never bothered anyone.Why then the fact that Apple lied on the slowdown in iPhone, certainly by omission, is it a problem today?No doubt because it influences the use in a disproportionate way: no one has complained that the battery is not really 100 %full, thousands of people have felt the slowness of iOS 11 which can'Partially explain by an aggressive reduction in the performance of the old iPhone.

The problems raised by Apple are real and potentially dangerous, its logic of preservation of old devices is healthy and commendable, but its solution is questionable.Even though she makes sure to accompany the slowdown in product renewal cycles, even precedes by extending the software management of the old models, she is now accused of wanting to replace the products by slowing them downartificially.

A perception difference revealing a major communication problem. Était-il si difficile, « l’année dernière », d’annoncer clairement cette nouvelle politique ? Et aujourd’hui, est-il si difficile d’indiquer clairement l’état de la batterie dans la section idoine des réglages ? Il ne s’agit pas seulement d’indiquer que la batterie doit être remplacée (comme iOS le fait déjà)), mais plutôt de prévenir dès qu’elle commence à être dégradée (comme le fait macOS)), et que le système doit prendre des mesures palliatives.

Without necessarily being able to deactivate the clamping, justified even if it is severe, the user would be at least informed.In the absence of this information, it must today use applications all the less reliable as the API allowing to raise the battery level has disappeared with iOS 10, or turn to social networks to try to find asolution… or muggish against a large international conspiracy.

… And consistency

In the presence of this information, the user would know the origin of the slowdown in his iPhone, and could perhaps even understand it.Things would have at least the merit of being clear: the user could accept the degradation of performance in favor of the extension of the life of the battery, or pay a few tens of euros to replace the battery in order to prolong the life ofits whole device.Unfortunately, this replacement is not necessarily possible.

"The Apple limited warranty covers a defective battery," explains Apple, "but not normal wear and tear.Only batteries that have lost more than 20 % of their initial capacity can be replaced immediately, an operation billed at € 89, the batteries being considered as wear parts.The operation is free if you have taken out an Applecare contract, or if the battery shows more severe dysfunction signs.

Apple will systematically refuse to replace a battery "in the green", to use the words of a "genius" that we interviewed on this subject, even if you wave € 89 under the nose of your interlocutor."A battery requires delicate recycling," explains this employee, "and recycling a battery in good condition is waste."This penalizes customers who would like to see us for real problems," adds another genius.

But the slowdown in an iPhone is indeed a "real problem" when the frequency of the processor of an iPhone 6 goes from 1.4 GHz to 600 MHz because the battery is worn, but not enough to be replaced without long negotiations.Without calling for rare and dear materials waste, we can probably claim a little more consistency from Apple.