How can I stop the battery deterioration

iPhone: battery and performance

Learn more about iPhone performance and how it relates to the battery.

The iPhone is designed to be easy and effortless to use. This is only possible thanks to a combination of the latest technologies and sophisticated technology. A key technological area is that of battery and performance. Batteries are based on complex technologies, and many factors can affect battery and connected iPhone performance. All rechargeable batteries wear out over time and have a limited lifespan. Ultimately, capacity and performance will decrease, so the batteries will need to be replaced. As the batteries age, the iPhone's performance can change. We have compiled this information for those who want to learn more.

Information on lithium-ion batteries

iPhone batteries use lithium-ion technology. Compared to older battery technology, lithium-ion batteries charge faster, last longer and offer higher power density, resulting in longer battery life with less weight. Rechargeable lithium-ion batteries are currently the best technology for your device. Find out more about lithium-ion batteries here.

Maximize battery performance

"Battery life" is the length of time you can use your device before it needs to be recharged. "Battery life", on the other hand, is the amount of time you can use your device before the battery needs to be replaced. The running time and the service life of the battery depend, among other things. how you use your device. In either case, there are ways to maximize these two values. Battery life depends on its "chemical age", which is based on more than just elapsed time. Various factors, such as the number of charging cycles and how the device was treated, play a role here. Follow these tips to maximize battery performance and extend battery life. For example, leave your iPhone half-charged if you won't be using it for an extended period of time. Also, avoid charging or leaving the iPhone in a warm environment or in direct sunlight for long periods of time.

Chemical aging of batteries

All rechargeable batteries are wearing components and their performance decreases with increasing chemical age.

As a lithium-ion battery ages chemically, its ability to hold a charge decreases. Therefore, the device needs to be recharged more often. The maximum capacity - i.e. the battery capacity compared to a new battery - changes. A battery's ability to provide maximum instantaneous performance, or "peak performance", can also decrease. In order for a smartphone to function properly, the electronics must be able to draw energy from the battery immediately. One characteristic that affects instantaneous energy delivery is the impedance of the battery. A high impedance battery may not be able to provide enough power when a system needs it. The impedance of a battery can increase with increasing chemical age. The impedance of a battery temporarily increases when the state of charge is low and in a cold environment, and this effect is much stronger when it is old. These are typical chemical properties of batteries that all lithium-ion batteries in the industry have.

As power is drawn from a battery with a higher impedance, the voltage on the battery will drop more. However, electronic components require a minimum voltage to function properly. These components include the device's internal memory, electrical circuits, and the battery itself. The power management system determines the battery's ability to deliver the energy it needs and regulates the load to keep it running. If operations can no longer be maintained without restricting the power management system, the system switches off to protect the electronic components. Even if the device is intended to be switched off in this way, it may be unexpected for the user.

Avoid unexpected shutdown

The lower the battery level and the higher the chemical age or the lower the temperature, the more likely it is that the device will turn off unexpectedly. In extreme cases, the device switches itself off again and again, making it unreliable or unusable. For the iPhone 6, iPhone 6 Plus, iPhone 6s, iPhone 6s Plus, iPhone SE (1st generation), iPhone 7 and iPhone 7 Plus, iOS dynamically manages power peaks to prevent the device from turning off unexpectedly. So the iPhone can continue to be used. This battery power management was specially developed for the iPhone and is not available on other Apple devices. As of iOS 12.1, this function is available on the iPhone 8, iPhone 8 Plus and iPhone X; on the iPhone XS, iPhone XS Max and iPhone XR this function is available from iOS 13.1. The impact of power management on these newer models may be less noticeable because of their more modern hardware and software design.

This type of battery power management is based on the combined analysis of device temperature, battery charge status and battery impedance. Only when these variables require it, iOS regulates the maximum performance of some system components such as CPU and GPU dynamically in order to avoid unexpected shutdown. As a result, high, rapid power peaks no longer occur at the same time, instead the utilization of the device is automatically adjusted and system processes are evenly distributed. In some cases, the user will not notice any difference in everyday device performance. The extent to which changes are noticeable depends on how much battery power management is necessary for a particular device.

In cases that require extensive battery power management, the user may notice the following:

  • Apps start slowly
  • Lower frame rate when scrolling
  • Dimming of the backlight (can be reset in the control center)
  • Volume up to -3 dB lower
  • Gradually decreasing frame rate in some apps
  • In extreme cases, the camera's flash will be disabled (this is shown in the camera user interface)
  • Apps that are updated in the background may have to be reloaded after starting

Many important areas are not affected by this battery power management. These include:

  • Quality of phone calls over the cellular network and transmission capacity over the network
  • Quality of the photos and videos taken
  • Performance of the GPS
  • Location accuracy
  • Sensors like gyroscope, accelerometer, barometer
  • Apple Pay

If the battery charge level is low and temperatures are low, the changes made by the battery power management are temporary. However, when a battery has chemically aged heavily, these changes can be more long-term. This is because all rechargeable batteries wear out over time and have a limited lifespan, so they will eventually need to be replaced. If this affects you and would like to increase the performance of your device, replacing your battery can help.

iOS 11.3 and newer

In iOS 11.3 and newer, this battery power management is optimized by regularly checking what level of power management is necessary to prevent an unexpected shutdown. If the battery condition can meet the determined maximum performance requirements, the battery performance management is reduced. If the device switches off unexpectedly again, the battery power management is strengthened. This assessment takes place on an ongoing basis in order to adapt the battery power management flexibly.

The iPhone models iPhone 8 and later have more modern hardware and software design so that the energy requirements and the ability of the battery to deliver power can be estimated more precisely. This can help maximize overall system performance. Therefore, they also have a different battery power management system that iOS can use to more precisely predict and avoid unexpected shutdowns. Therefore, the impact of battery power management on iPhone 8 and later may be less significant. The capacity and peak performance of the rechargeable batteries in all iPhone models will decrease over time, so the batteries will eventually need to be replaced.


Battery condition

For the iPhone 6 and newer, iOS 11.3 and newer offer new functions for displaying the battery status and for replacement recommendations. You can find this under "Settings"> "Battery"> "Battery status".

In addition, the user can see whether the battery power management, which dynamically manages the maximum power to prevent unexpected shutdown, is activated. The user can also deactivate the battery power management. The function is only activated on a device with reduced immediate energy supply after the first unexpected switch-off. This feature is available on the iPhone 6, iPhone 6 Plus, iPhone 6s, iPhone 6s Plus, iPhone SE (1st generation), iPhone 7 and iPhone 7 Plus. As of iOS 12.1, this function is available on the iPhone 8, iPhone 8 Plus and iPhone X; on the iPhone XS, iPhone XS Max and iPhone XR this function is available from iOS 13.1. The impact of power management on these newer models may be less noticeable because of their more modern hardware and software design.

(Note: On devices updated from iOS 11.2.6 or older, the battery power management is initially deactivated. It is only activated if an unexpected shutdown occurs.)

All iPhone models have basic battery power management to ensure that the battery and system as a whole are performing as intended, and that internal components are protected. This concerns the behavior at high or low temperatures as well as the internal voltage management. This form of battery power management is required for safety and proper functioning and therefore cannot be deactivated.

Maximum capacity of the battery

The Battery Health screen provides information about the maximum battery capacity and maximum performance.

The maximum battery capacity indicates the battery capacity of the device in relation to the new condition. Chemical aging reduces battery capacity. This can potentially reduce the usage time between charges. Depending on the length of time between the production of the iPhone and its activation, the battery capacity may be slightly less than 100%.

A typical battery typically retains up to 80% of its original capacity over 500 full charge cycles under normal operating conditions. The one-year guarantee also covers the servicing of a defective battery. Outside of the warranty, Apple offers battery service for a fee. Learn more about charge cycles here.

The worse the battery condition, the less the battery's ability to deliver maximum performance. The Battery Health screen includes a maximum performance area where the following messages can be viewed.

Performance is normal

If the battery condition can support normal maximum performance and the battery power management is not activated, you will see the following message:

Your battery currently supports normal maximum performance.

Battery power management activated

If the battery power management has been activated, you will see the following message:

This iPhone suddenly shut down because the battery was unable to perform at its maximum capacity. The battery power management has been adjusted to avoid this in the future. Deactivate …

If you deactivate battery power management, you cannot reactivate it. It will be reactivated automatically if the device unexpectedly switches off again. Then the option to deactivate is available again.

Unknown battery condition

If iOS is unable to determine the battery condition, you will see the following message:

This iPhone cannot check the battery condition. An Apple-authorized service provider can service the battery. More information about service options ...

This could be due to an incorrectly installed battery or an unknown battery part.

Battery power management deactivated

If you turn off battery power management, you will see the following message:

This iPhone suddenly shut down because the battery was unable to perform at its maximum capacity. You have manually deactivated battery power management.

If the device unexpectedly switches off again, the battery power management is reactivated. Then the option to deactivate is available again.

Bad battery condition

If the battery condition deteriorates significantly, you will also see the following message:

The condition of your battery has deteriorated significantly. An Apple-authorized service provider can replace the battery to restore full performance and capacity. More information about service options ...

This message does not indicate a security issue. The battery can still be used. However, there may be more noticeable battery and performance issues. With a replacement battery, you can make better use of your device.

Important battery message

If you see the following message, it means your iPhone's battery could not be verified. This news affects the iPhone XS, iPhone XS Max, iPhone XR, and newer models.

It has not been verified that this iPhone has a genuine Apple battery. Battery health information is not available for this battery.Additional Information...

Battery health information is not available. Contact an Apple Authorized Service Provider to have your battery checked. More information about service options.

Learn more about this message as it appears on iPhone 11 and iPhone 11 Pro.

Recalibrating the battery health report on the iPhone 11, iPhone 11 Pro, and iPhone 11 Pro Max

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