Battery Life and Health

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All iPhones come with a Lithium Ion battery designed to maximize the speed and lifetime of your device. While Lithium Ion batteries do not last forever – just like all batteries they chemically degrade over time – they are a long lasting and reliable component that improves user experience. This section will go over the general capabilities of batteries, certain settings that you can enable to maximize your battery life, as well as ways to quickly check your battery’s overall health.

Battery Performance and Upkeep

Apple batteries are closely tied into the performance of your device, and as such if your battery is not performing at its maximum capacity, then your phone will not either. The term “maximum capacity” refers to the amount of charge that the battery can hold when it is fully charged – as the battery ages this number will decrease, as the battery will no longer be able to store the total amount of energy it did originally. As the maximum capacity decreases, you will notice that the time it takes for your battery to lose its charge will decrease as well. We recommend that you replace your battery when its maximum capacity reaches 80%, and the length of time it may take for your battery to reach this capacity varies depending on general usage.

If the battery has aged to a point where it can no longer support the other hardware components on the machine, then the device will shut down. These shut downs typically occur when the battery can no longer provide the necessary power output to sustain operations, and as a result the device will shut itself down in order to protect the other components. So, if you begin to notice that your device is shutting down unprompted, even when the battery still has a charge, your battery is most likely in need of replacement. If you notice either a decrease in battery life, or random shutdowns occurring, reach out to your nearest Apple store or Apple service provider. 

There are several ways to maximize the performance of your battery, these general tips can both increase the lifetime of your battery – that is, the length of time is takes to consume a full charge – as well as the lifespan of your battery – that is, the complete age of the battery from its manufacturing date to when it needs to be replaced. The best rule is to make sure that your device is both stored and charged in moderate temperatures. If your device is left in either extremely hot or extremely cold environments for extended periods of time, then this can negatively affect your battery, causing the component to degrade at a faster rate. For the lithium ion batteries in phones specifically, any temperatures hotter than 95 degrees fahrenheit or colder than 32 degrees fahrenheit will damage the battery, or at the very least affect iPhone performance.

Another tip that we recommend is to ensure that if you are not going to be using your device for extended periods of time, that you drain the battery to a half charge before fully shutting down the device and storing it. If the battery is fully drained when it goes into storage, this may prevent the phone from powering back on when you proceed to use it again, and conversely the battery can lose capacity if it is stored for long periods of time while fully charged. You should note that when powering on your device for the first time after an extended period of being shut down the boot time for your phone may be longer than normal. In fact, you may need to leave the phone on the charger for at least twenty minutes before the phone powers on. Additionally, iPhone batteries manage their own capacities, meaning that it is no longer necessary to allow your battery to completely die before recharging.

Last but not least, make sure that your device is running the latest operating system. If your device is up to date, then all your hardware will be running optimally, including the battery, and your performance management systems can properly ensure that your battery power output is correctly calibrated to maintain operations and system performance. For more information on iOS updates, see our topic “iOS: When You Should Upgrade” included in the iOS course.

Battery Health and Usage

On devices running iOS 11.3 and later there is a section available in Settings that allows users to check the health of their battery, as well as track their daily battery usage. These features provide phone owners with the opportunity to monitor the health of their devices, and determine what digital activities consume the most power on their phone. Similarly, the battery health feature can notify iPhone users if their battery is in need of replacement or service.

To check the health of your battery, follow these steps:

  • Open Settings
  • Select “Battery”
  • Select “Battery Health”

On the next screen your maximum capacity will be listed, as we stated previously, we recommend  battery replacement when your maximum capacity reaches 80%, at this point performance will begin to deteriorate, and you may notice shorter battery life or random shut downs.

This screen can also notify you if your battery can no longer support peak performance capability. As a result, if your battery has aged or degraded to the point where it affects the overall performance of the device, then you will be able to see that here. If your device has experienced an unexpected shutdown due to insufficient battery output, then you will receive a notification indicating that peak performance management has been applied in order to prevent future shutdowns. In more extreme cases, you may notice certain changes to your device, such as slower frame rates, longer launch times for applications, as well as backlight dimming and an overall lower speaker volume. If you choose to do so, you may disable this feature, but please note that you cannot re-enable it manually, however it will reactivate automatically if the phone experiences another shutdown.

You can also turn on or turn off optimized battery charging at the very bottom of this screen using the green toggle switch. This feature allows your device to track your general usage, in particular when you charge your device,  in order to preserve battery age. To do so, your device will only charge your phone fully, or past 80%, when you need to use it, and this will be determined by your history of battery usage. We recommend turning this feature on if you have not already done so, as it has been shown to maximize the lifespan of your battery.

To check battery usage, follow these steps:

  • Open Settings
  • Select “Battery”

On the next screen, under “Battery Usage” are two charts that provide a history of your battery charge and activity over time. The first chart depicts your battery charge throughout the day. If the bars are underlined, then this means that during this period your phone was charging. If the bars are yellow, this means that your phone was in low power mode, and if the bars are red, this means that your battery was below 20% charge. However, if you toggle this chart to show the past ten days, then it becomes less specific, rather than being able to track the battery charge for each hour of the day, you can now only view how much of your battery’s charge you consumed per day.

The chart below shows the various levels of activity on your device by time. If you are on the chart that collects data form the past 24 hours, you will be able to see a breakdown of your usage by hour, as well as how much of that usage was taken by active and passive screen time, that is, whether you were engaging with the application, or whether it was running in the background – these two categories are designated by screen on and screen off. Each bar on the activity chart shows an hour of usage, and how much of that hour has been spent on the phone. These bars are further divided into screen on or screen off activity, with the lighter blue sections designating background activity, and the darker blue sections depicting active engagement.

If you scroll down further you can also see a list of applications, these applications are listed in order of the amount of time spent on the platform, as well as the percentage of battery usage. To toggle between the two, select the blue title above the right hand column, which will say either “Show Battery Usage” or “Show Activity” depending on which category you currently have selected.

Similar to the battery usage chart, you can adjust the time period of the activity chart to display the past 10 days, rather than the past 24 hours. The graph will now instead display the total hours of activity per day, and the list of applications will show the total hours of usage over the past 10 days, rather than 24 hours. Additionally, you can select specific days by tapping on the bar that represents that day, and the usage or activity by app section will adjust accordingly to show the breakdown of either battery percentage or time spent on each application.

Takeaway: The Lithium Ion batteries installed in iPhones have a limited lifespan, but there are certain settings or features that you can enable to maximize the efficiency and performance of your battery. You can also monitor the overall condition and health of your battery, as well as track app usage and activity, using the battery section of your settings on iPhones running iOS 11.3 or later.