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Understand how the “Battery Health” feature of iOS 11.3 works and how you can make your iPhone faster

Battery chemistry is really giving Apple a job. The company is doing everything to erase the image of vile in this story and, with the introduction of the resource Battery Health in the second beta version of iOS 11.3, she decided to put on the air a support article explaining absolutely everything about this component so in vogue these days.

In the document, Apple again explains about lithium-ion batteries (how it is still the best option compared to other battery technologies) and what you can do to maximize their performance (for example, keeping the iPhone at half charge when stored for a long period and avoid charging or leaving the iPhone in hot environments, including direct sunlight for long periods of time). So, nothing we don't know.

Chemically "old" battery

What we do not know about the relationship of the battery to the performance of the iPhone. See just this explanation from the company about what a chemically "old" battery is and, of course, its direct relationship with the performance of the device:

As lithium-ion batteries ?age? chemically, their ability to keep charge down, resulting in shorter periods of time for recharging the device. This can be called maximum battery capacity, which is a measure of the battery's capacity compared to when it was new. In addition, the battery's ability to provide maximum instant performance, or ?peak power?, may decrease. For the phone to function properly, the electronic components must be able to obtain battery power instantly. An attribute that affects this instantaneous power supply is the battery impedance. A high impedance battery may not be able to provide enough power for the system that needs it. The impedance of the battery can increase if the battery is older in age. The battery impedance will temporarily increase in a low-charge state and in a cold temperature environment. When this is combined with a higher chemical age, the increase in impedance will be more significant. These are chemical characteristics of the battery, which are common to all lithium ion batteries in the industry.

When power is obtained from a battery with a higher impedance level, the battery voltage will drop to a greater degree. Electronic components require a minimum voltage for proper operation. This includes the device's internal storage, the power circuit and the battery itself. The power management system determines the capacity of the battery to supply this power and therefore manages the loads to keep it running. When operation can no longer be maintained with the full capacity of the power management system, the system will perform a shutdown to preserve these electronic components. Although this shutdown is intentional from the device's perspective, it may be unexpected by the user.

Apple's solution

This is exactly why Apple introduced dynamic management of peak performance in iOS some time ago, in order to avoid unexpected shutdowns so that the iPhone can still be used. This performance management feature is specific to the iPhone (models 6, 6 Plus, 6s, 6s Plus, SE, 7 and 7 Plus) and does not apply to other Apple products.

This performance management works like this: iOS analyzes a combination of device temperature, battery charge status and battery impedance. Only if these variables require it, the system will dynamically manage the maximum performance of some system components, such as CPU and GPU, to avoid unexpected shutdowns. In this way, the device's workloads will be automatically balanced, allowing for better distribution of system tasks, instead of fast, higher performance peaks at once. Also according to Apple, in some cases, the user may not notice differences in the daily performance of the device; the level of perceived change depends on how much performance management is required for a given device.

Going to the extreme example of the thing, in which the user experience is actually hampered by this reduction in performance, Apple explained that the following areas / actions in the system can be affected: longer app launch times, lower frame rates during scrolling, dimming the backlight (which can be replaced in Control Center), lower speaker volume (up to -3dB), gradual reductions in frame rate in some apps, camera flash will be disabled as visible in the camera user interface (in more extreme cases) and apps being updated in the background that may require reloading after startup.

Many key areas of the system, however, are not affected by this performance management feature, including network transfer rate and cell call quality, quality of captured photos and videos, GPS performance, location accuracy, sensors such as gyroscope, accelerometer and barometer, in addition to Apple Pay.

What's new in iOS 11.3

With the controversy formed, Apple had to act. And acted. So, in iOS 11.3 (which is still in the testing phase and will only be released to everyone within a few months), we have news related to the health of the battery and the performance of the processor itself when the battery is chemically "old".

IOS 11.3 periodically evaluates the level of performance management required to avoid unexpected shutdowns. If the battery's health level is able to meet the observed peak power requirements, performance management needs to be less. If an unexpected shutdown occurs again, then performance management will be greater. This continuous assessment allows for more adaptive performance management.

iPhones 8, 8 Plus and X "out"

Apple stressed that the models 8, 8 Plus and X have a more advanced hardware and software design, which provides a more accurate estimate of the power needs and the power capacity of the battery to increase the overall performance of the system. This allows a different performance management system, allowing iOS to have a more accurate forecast and avoid an unexpected shutdown. Consequently, performance management impacts may be less noticeable on these newer devices.

Still, over time, rechargeable batteries in all iPhone models will have their capacity and peak performance decreased and, at some point, will need to be replaced.

The ?Battery Health? feature

Battery Health on iOS 11.3

For iPhone 6 and later models, iOS 11.3 offers new features that show the battery's level of health and recommend if you need to replace the battery. These resources are available in Battery Health Settings (Beta).

In addition, users can see if the performance management feature (to avoid unexpected shutdowns) is enabled, and can choose to disable it. It is worth noting that this feature is automatically activated by the system only after the first occurrence of an unexpected shutdown on a device with diminished capacity to provide maximum instantaneous power. It applies to iPhones 6, 6 Plus, 6s, 6s Plus, SE, 7 and 7 Plus. That is, a device that is upgraded to iOS 11.3 has performance management initially disabled; it is reactivated if the device subsequently experiences an unexpected shutdown.

All iPhone models include basic performance management to ensure that the battery and system in general function as expected, and internal components are protected. This includes behavior at high or low temperatures, as well as internal voltage management. This type of performance management is necessary for security and expected operation, and cannot be disabled.

Maximum battery capacity

The ?Battery Health? feature includes information on maximum battery capacity, as well as peak performance capacity. The maximum battery capacity measures the battery capacity of the device in relation to when it was new. Batteries will start at 100% when they are activated for the first time and will have their capacity decreased as they age ?chemically?, which can result in fewer hours of use between charges.

As we have already explained here on the website, a normal battery is designed to retain up to 80% of its original capacity in 500 full charge cycles when operating under normal conditions. Apple's one-year warranty includes service coverage for a defective battery, meaning if a battery runs out of less than 80% during the first year of using the device, you can exchange it free of charge at an Apple store or at an Apple Authorized Service Center. If it is out of warranty, Apple will offer the service at a cost (currently R $ 149).

As battery health declines, the ability to provide peak performance may also be decreased. The ?Battery Health? screen includes a section for ?Peak Performance Capacity?, where the following messages may appear:

  • The battery is providing normal peak performance at the moment. That is, there is nothing to worry about;
  • This iPhone was shut down unexpectedly because the battery was unable to provide the peak power required. Performance management has been applied to help prevent this from happening again. Disable. If you disable performance management, you can enable it again. It is worth noting that it will be activated again automatically if an unexpected shutdown occurs;
  • This iPhone could not determine the health of the battery. An Apple Authorized Service Provider can service the battery. More about maintenance options. This message may appear due to improper battery installation or an unknown battery part;
  • This iPhone was shut down unexpectedly because the battery was unable to provide the peak power required. You have manually disabled performance management protections.. When you manually disable performance management, this is the message that appears. If the device experiences an unexpected second shutdown, the performance management features will be applied again and, if you want, you can disable it again;
  • The health of the battery is significantly degraded. An Apple Authorized Service Provider can replace the battery to restore maximum performance and capacity. More about maintenance options. what appears when the battery health is already very low. This message does not indicate a security problem and the battery can still be used. However, you may see more problems involving the battery and performance, so replacing the battery is the most recommended.

Simply placing a switch by which we can easily enable / disable the feature (as I and many probably imagine) would not be the best option. ?Hiding? the activation as a simple link in a word and on top of that activating the feature automatically always after an unexpected shutdown seemed to me a great way to implement performance management, taking into account the lay / hasty behavior of many users.

And you, what did you think of the explanation of Apple and the measures taken?