Find out how iPhone performance depends on battery life.
iPhone is designed to be simple and easy to use. This was achieved thanks to a combination of the most modern technologies and advanced engineering solutions. An important area of application of such technologies is related to the influence of the battery on performance. A battery is a sophisticated technology product. Battery and iPhone performance generally depends on a number of factors. All rechargeable batteries are consumables and have a limited life. Over time, their capacity and performance decreases, so there is a need for replacement. When the battery reaches its end of life, iPhone performance may decline. We have prepared this article for those who need more information.
Li-ion Battery Information
The iPhone uses lithium-ion batteries. Compared to previous types of batteries, lithium-ion batteries charge faster, discharge longer, have a higher charge density and lower weight. The rechargeable lithium-ion battery technology is the best available today. Learn more about lithium-ion batteries.
Maximize battery performance
Battery life is the amount of time a device works without recharging. Battery life is the amount of time that the battery is working properly until a replacement is needed. Battery life and battery life depend, in particular, on the tasks performed. No matter how you use the device, its performance can be improved. Battery life is associated with its “chemical age,” which is not just a period of time. Other factors should be considered, such as the number of charge cycles and compliance with the operating rules. Follow these guidelines to maximize battery performance and extend battery life. For example, leave your iPhone half charged if you are not going to use it for a long time. Also try not to charge or leave the iPhone in places with high temperature, including in the open sun, for a long time.
Chemical aging of batteries
All rechargeable batteries are consumable components whose performance decreases as they age.
With the chemical aging of lithium-ion batteries, the amount of charge that they can accumulate decreases, as a result of which the device has to be charged more often. This is called a decrease in the maximum battery capacity. a value that is measured as the ratio of the current capacity to the capacity of a new battery. Among other things, the maximum instantaneous battery performance (or peak power) may decrease. To ensure the correct operation of the device, electronic components must be instantly powered by a battery. One of the factors that affects such an instant charge return is the battery impedance. A battery with high impedance cannot always give off the charge in the amount needed for the system. The battery impedance may increase as it chemically ages. It temporarily increases at a low charge level and at low ambient temperatures. With a large chemical age, it increases more significantly. These are chemical characteristics common to all lithium-ion batteries.
When a charge is removed from a battery with high impedance, the voltage can drop significantly. Correct operation of electronic components requires a certain minimum voltage. These components include the device’s internal data drive, power circuits, and the battery itself. The power management system determines the ability of the battery to supply the necessary power and manages the load to maintain performance. When all the capabilities of the power management system are exhausted and it is impossible to maintain operability, the system shuts down to protect electronic components. Although the device shuts down intentionally, this may come as a surprise to the user.
Prevent unexpected device shutdown
At low charge, high chemical age or low temperatures, unexpected shutdown occurs more often. In extreme cases, shutdowns can occur quite often, making the device unreliable or completely unusable. iOS on iPhone 6, iPhone 6 Plus, iPhone 6s, iPhone 6s Plus, iPhone SE, iPhone 7 and iPhone 7 Plus dynamically controls peak performance, preventing iPhone from shutting down unexpectedly and extending its life. Performance management is only available on iPhone and is not available on other Apple products. This feature is available on iPhone 8, iPhone 8 Plus and iPhone X with iOS 12.1 or later and on iPhone XS, iPhone XS Max and iPhone XR with iOS 13.1 or later. Performance management performance on these new models may be less noticeable with advanced hardware and software.
It allows you to monitor the temperature of the device, the state of charge of the battery and the total resistance of the battery. Only with a certain combination of this data in iOS, the performance of some system components, such as the central and graphic processors, is dynamically controlled to prevent unexpected shutdowns. As a result, the workloads of the device are automatically balanced, which allows you to distribute system tasks more evenly and eliminates the occurrence of instantaneous performance peaks when they are simultaneously performed. Sometimes the user may not even notice changes in the daily performance of the device. The level of perceived changes depends on how much you need to manage performance on a particular device.
When serious measures are required, the user may notice phenomena such as:
- slowing down the launch of programs;
- frame rate reduction during scrolling;
- decrease in backlight brightness (this can be changed in the Control Center);
- decrease in speaker volume by 3 dB;
- gradual decrease in frame rate in some programs;
- disabling the camera flash in extreme cases (this is reflected in the camera interface);
- the need to restart when starting programs that are updated in the background.
Performance management does not affect many important features. These include, but are not limited to:
- cellular quality and network bandwidth;
- quality of photo and shooting;
- GPS performance;
- geolocation accuracy;
- operation of sensors (gyroscope, accelerometer, barometer and others);
- work Apple Pay.
At low battery levels and at low temperatures, changes associated with performance management are temporary. If the device’s battery is significantly aged chemically, such changes may be more long-term. This is because all rechargeable batteries are consumables and have a limited life. Therefore, over time, they need to be replaced. If you have such a problem and want to improve the performance of your device, try replacing the battery.
For iOS 11.3 or later
In iOS 11.3 and later, the performance management function has been optimized: now the system periodically evaluates the required level of performance management to prevent an unexpected shutdown. If the state of the battery allows for predicted peak power, performance management actions will be minimal. In the event of a repeated unexpected shutdown, performance management will become more active. Evaluation is carried out regularly, which guarantees high flexibility in the operation of this function.
Thanks to the improved hardware and software of iPhone 8 and later, you can more accurately assess battery capacity and device power requirements, which increases overall system performance. Thus, performance management in iOS is carried out in a new way, which allows you to more accurately identify the threat of unexpected shutdown and prevent it. As a result, the performance management feature on iPhone 8 and later may be less noticeable. Over time, the capacity and peak performance of the battery on all iPhone models are reduced, and therefore requires battery replacement.
On iPhone 6 and later, after upgrading to iOS 11.3 or later, new features become available: view the battery status and notify you to replace it. These functions are in the “Settings” menu. “Battery” “Battery Status”.
In addition, users can check if the performance management function is enabled, which dynamically changes the maximum performance to prevent the device from turning off unexpectedly, and disable it if necessary. This function is activated only after the first unexpected shutdown of a device with a battery whose capacity is not enough to provide a sufficient level of maximum instantaneous power. The feature is available on iPhone 6, iPhone 6 Plus, iPhone 6s, iPhone 6s Plus, iPhone SE, iPhone 7 and iPhone 7 Plus. This feature is available on iPhone 8, iPhone 8 Plus and iPhone X with iOS 12.1 or later and on iPhone XS, iPhone XS Max and iPhone XR with iOS 13.1 or later. Performance management performance on these new models may be less noticeable with advanced hardware and software.
Note. After updating the device with iOS 11.2.6 or earlier, the performance management function will be disabled. It is activated if an unexpected shutdown of an updated device occurs.
All iPhone models are also equipped with a basic performance management system that is responsible for the proper operation of the battery and the device as a whole, as well as for protecting internal components. It depends on it (among other things) the operability of the device at high or low ambient temperatures, as well as the voltage on the internal components. This performance management system is essential for security and proper functioning. You cannot disable it.
Maximum Battery Capacity
The Battery Status screen displays information about maximum battery capacity and peak performance.
Maximum battery capacity is the ratio of current capacity to new battery capacity. As the battery chemically ages, its capacity decreases, and therefore, the battery life from it can be reduced. Depending on how much time has passed from the production date of the iPhone to the moment of its activation, the displayed battery capacity may be slightly less than 100%.
The standard battery is designed to maintain up to 80% of the original capacity after 500 full charge cycles when operating under normal conditions. The one-year warranty includes the right to service a faulty battery. If the device is not under warranty, Apple may charge you for the battery. For more information on charging cycles, see this page.
As the battery deteriorates, peak performance may decline. On the Battery Status screen, there is a Peak Performance section where the following messages may appear.
If the battery status allows you to maintain normal peak performance and performance management is not enabled, the following message will be displayed:
“The battery now supports normal peak performance.”
Performance Management Function Active
When the performance management function is activated, the following message appears:
“This iPhone turned off unexpectedly because the battery could not provide the required peak power. To help prevent such outages in the future, performance management has been enabled. Switch off…”
Please note that after disabling the performance management function, you cannot activate it manually. It is automatically activated in the event of an unexpected shutdown of the device. The ability to disable will also remain available.
Battery status unknown
If iOS cannot determine the battery status of the device, the following message will be displayed:
“Failed to determine the battery status on this iPhone. An Apple Authorized Service Center can service the battery. about battery maintenance “
This may occur due to improperly installed or unrecognized batteries.
Performance Management Disabled
If you disable the active performance management function, the following message appears:
“This iPhone turned off unexpectedly because the battery could not provide the required peak power. Performance management has been manually disabled. ”
If the device shuts down unexpectedly, the performance management function is activated again. The ability to disable will also remain available.
Battery condition has deteriorated
If the battery condition deteriorates significantly, the following message appears:
“The battery condition has deteriorated significantly. You can replace the battery at an Apple Authorized Service Center to restore full capacity and performance. about battery maintenance “
This message is not a security warning. The battery can still be used. However, problems with battery power and performance may be exacerbated. To operate the device in accordance with the technical specifications, replace the battery.
Important Battery Message
If the following message appears, it means that you cannot check the iPhone battery. This post applies to iPhone XS, iPhone XS Max, iPhone XR, and later.
Failed to confirm that this iPhone uses an Apple battery. Information about its state is not available for this battery. Additional Information.
Status information for the specified battery is not available. To check the battery status, contact an Apple Authorized Service Center. Learn more about service options.
If a used battery significantly degrades the performance of your device and you would like to replace it, contact Apple Support and find out about available service options.