In the wake of backlash from users in December last year, Apple announced that it is working on bringing a solution. The solution was in response to Apple’s own power management feature which was introduced in iOS 10.2.5. Users reported slow performance on their iPhones, and when Geekbench investigated into the matter and found out that Apple introduced CPU throttling in iOS 10.2.5 to compensate for phones whose batteries cannot meet peak power delivery, Apple issued a public apology and promised to address the issue in a future update.

We reported earlier that the said feature is coming in iOS 11.3 and the update is being tested by developers in beta. Apple has put up a support page outlining power battery power management works in iOS 11.3. The support page is extensive, it educates consumers on various topics such as Lithium-ion technology and why Apple had put the feature in the first place, which was not to force users to upgrade, as many users believe was the intention.

Apple reiterates that due to the nature of Lithium-ion technology, batteries have a chemical age that shortens overtime as you continue to recharge it. “All rechargeable batteries are consumables and have a limited lifespan”, describes Apple.

“As lithium-ion batteries chemically age, the amount of charge they can hold diminishes, resulting in shorter amounts of time before a device needs to be recharged. This can be referred to as the battery’s maximum capacity—the measure of battery capacity relative to when it was new. In addition, a battery’s ability to deliver maximum instantaneous performance, or “peak power,” may decrease. In order for a phone to function properly, the electronics must be able to draw upon instantaneous power from the battery. One attribute that affects this instantaneous power delivery is the battery’s impedance. A battery with a high impedance may be unable to provide sufficient power to the system that needs it. A battery’s impedance can increase if a battery has a higher chemical age. A battery’s impedance will temporarily increase at a low state of charge and in a cold temperature environment. When coupled with a higher chemical age, the impedance increase will be more significant. These are characteristics of battery chemistry that are common to all lithium-ion batteries in the industry.”

To compensate for aging batteries, iOS adjusts CPU and GPU frequencies so your phone does not randomly shutdown if the battery is not able to provide to instantaneous peak loads. However, with iOS 11.3 it is now possible to turn off this battery power management completely. Here is how the new battery health app will suggest actions based on current battery condition and past random shutdowns.

Battery can meet peak performance: In this case, power management will not be applied.

After a random shutdown: Battery power management will kick in once the iPhone has experienced its first random shutdown. It is by default set to disabled. As previously mentioned, you can turn off the feature completely, enabling possibility that the phone might experience random shutdowns.

Battery health cannot be determined: This could happen due to an “improperly installed battery or an unknown battery part”. Apple suggests seeking help from an Authorized Service Provider.

Battery has degraded significantly: Once the battery has aged past a certain point when power management will be stricter, the app will recommend a battery replacement.

It is evident that Apple has taken the whole outrage seriously. The app provides useful insight about the battery and iOS’ protocols, where previously users had no clue as to why their devices were running slow. Since Apple is known to support its older devices with software updates for far longer than any other phone maker, you can potentially stick on an older iPhone by simply replacing the battery.

Author: Jawwad Iqbal

Having written on tech for years now, Jawwad Iqbal took his passion for sharing news and opinions with the inception of Hardware Blitz. He holds a firm view that quality content drives long-term success.