Have you ever wondered how much of your battery is being used? Or been in a quick pinch and you’re desperate to make your device last the whole day? Even though it’s at 18% and you won’t be able to access a charger for several hours?  Or have you ever wondered why sometimes when you use certain apps your battery dramatically drains? New in the iOS 9 Settings application is the ability to put your device in Low Power Mode.

Low Power Mode temporarily reduces power consumption until you can fully recharge your device. When it is turned on, the system notifications, mail fetch, background app refresh, automatic downloads and visual effects are reduced or turned off.

When you are using the device and have the battery get down to 20%, you’re iPhone pops up with a notification in the middle of whatever you are doing. The notification informs you that you have a low battery with 20% remaining, and suggests turning on Low Power Mode. To activate Low Power Mode, just tap on the option on the alert. Normally when the battery has less than 20% remaining, the color in the battery icon in the upper right hand corner is red. When you turn on Low Power Mode, the color in the battery icon is yellow to indicate reduced activity.

Alternatively, to manually put on Low Power Mode at any time, open up Settings and scroll down until you see Battery.

Then you are able to turn on Low Power Mode by tapping on the white circle toggling to green.

When you charge the device, Low Power Mode will automatically turn off when the battery gets sufficiently charged, usually around 80% charge.

With iOS 9, by default the Battery Percentage is turned off except when using Low Power Mode. For everyday usage, I recommend turning it on, as it will immediately give you a better representation of what your battery life is as opposed to the picture of the battery.

Here you also have some information about the battery, which is very similar to the battery settings in iOS 8. You will see a list of the apps and how much the app has used the battery. It will display the information for the past 24 hours as well as the last several days. This information can help you determine if you are constantly using certain apps or it could be due to background activity. Tapping on the clock icon next to the battery usage will break down the data even further, telling you how long the app has been on the screen, and how long it’s been running in the background. All the way down at the bottom shows the Time Since Last Full Charge. It shows you your Usage, how long you have actually been engaged with the device using the display and it will show you Standby, how long the device has been idle and not been used.

There are several different reasons why apps will use a lot of the battery:

  • The app is being constantly used by you. In my example above, that is precisely the case with Tweetbot.
  • The app is being used in the background. It could be downloading content, uploading content, using location services or streaming audio.
  • The app is being used in an area with poor cellular service. When this happens, it puts more work on the battery and drains it quickly. If this happens, the Phone app will be listed and it will list low signal.
  • The app is not working properly. For example the app can be constantly crashing. Or the app you barely use, but yet it is at the top of the list.
  • The app is using AirPlay. The app is streaming audio to AirPlay speakers, or video to an Apple TV.

Now that you know how to turn on Low Power Mode and how to monitor your battery, your iPhone battery life should last longer.