How To: Here’s What Happens To Your iPhone Every Time You Turn On Low Power Mode

When you turn on power saving mode on your iPhone, it’s not always clear what steps it takes to reduce battery drain and conserve power. Changes to power-hungry features you use daily may be immediately noticeable, but some features you use frequently may be turned off or reduced without any obvious sign.

Your iPhone will ask if you want to turn on low power mode when the battery level reaches 20% and the remaining charge is 10%, but this is not necessary. You can also turn it on or off manually from Settings -> Battery, Control Center, or Siri, and you can even automate it on a schedule or with specific triggers through the Shortcuts app.

Regardless of how you activate it, Power Saving Mode will take certain power-saving measures to keep your battery running longer until you have time to charge it. But you may not want some features that have been disabled or reduced to be affected, which will help you decide if low power mode is needed or not. So knowing what’s going on can be important.

Plus, knowing all the tasks that power saving mode temporarily affects, you’ll be able to use it whenever it helps curb a particular feature, even if your battery is reasonably charged.

No matter why you use Low Power Mode, it will automatically turn off when your iPhone’s battery level rises to 80% or above. Some of the features and tasks listed below may work as normal when power saving mode is turned on when the iPhone battery is 80% or higher.

1. Disables 5G (mostly)

iPhone 12 series models, iPhone 13 series models, and iPhone SE (3rd generation) support 5G. You can get incredible speeds on your carrier’s 5G network, but not when power saving mode is turned on.

Low Power Mode disables 5G on your iPhone, pushing you to a 4G or LTE network until you turn off Battery Saver Mode. However, for video streaming and large downloads, you should still use 5G because it’s more efficient than using 4G or LTE for these tasks.

2. Disables 5G offline

5G Standalone is an excellent 5G network as it has a 5G network core making it self sufficient and it is not available from every carrier or mobile virtual network operator. T-Mobile is one of the few carriers to offer an offline service. Non-standalone 5G networks, which are more common, have a 4G LTE network core, which gives you some of the benefits of 5G, but not all that true 5G is capable of.

Low Power Mode disables offline 5G network access, but only on iPhone 12, iPhone 12 mini, iPhone 12 Pro, and iPhone 12 Pro Max. Unlike non-standalone 5G, video streaming and large downloads will not continue to use offline 5G as the entire connection will be dropped, so they will revert to live 5G networks.

3. Reduce screen brightness

The brightness of your iPhone’s display can drain your battery if you always use it at maximum. You can reduce power consumption by turning on auto-brightness or by adjusting the brightness in the Control Center or Settings, but the power saving mode also helps.

Whenever you turn on low power mode, your display dims slightly, and you may not even notice when this happens unless you look for it specifically. Your brightness controls will remain unchanged because iOS doesn’t actually adjust them when power saving mode is enabled.

Instead, the most likely culprit is the White Point Reduction feature, which reduces the amount of whites on the screen, lowering the overall brightness. The Reduce White Point slider only moves from 25% to 100%, so Apple can play around with 25% in low power mode.

When power saving mode is on, you will see a dim display regardless of whether you have White Point Reduction or Auto Brightness enabled or not.

4. Disables receiving email

Email accounts in the Mail app can either send you new emails as they hit the servers, receive new emails at intervals you set, or manually download new emails whenever you view an account or refresh its page. This is also true for other types of data in other apps, such as calendars, notes, contacts, and reminders associated with your email accounts. You can find these settings via Settings -> Mail -> Accounts -> Get new data.

Low power mode disables the fetch service, so you’ll have to check for new emails manually if those accounts aren’t set to push. When you turn off Power Saving Mode or your iPhone reaches a healthy 80% charge or higher, your download schedule will resume.

5. Reduces Auto-Lock waiting time

By default, iOS makes your display go to sleep after 30 seconds of inactivity. If you’ve disabled auto-lock or set it to 1, 2, 3, 4, or 5 minutes, Low Power Mode will change your display’s sleep time back to 30 seconds until it’s turned off.

6. Disables perspective scaling

Perspective zoom moves your home screen wallpaper and interface elements based on motion data from the accelerometer and gyroscope. The background moves much faster than the top layer of home screen icons, widgets, alerts, notifications, page dots, and the dock, creating a 3D illusion of depth and space with a parallax effect.

When power saving mode is enabled, perspective scaling is disabled, so there will be no background or foreground movement on the home screen until power saving mode is disabled.

Other motion effects such as weather animations in the Weather app, live wallpapers, zoom and slide effects for screen transitions, bubble and full screen effects in messages, most animations in the app, etc. will still animate when enabled. in power saving mode. Switching to “Reduce Motion”in Settings -> Accessibility -> Motion will also disable perspective scaling, but it will also affect the other motion effects I just mentioned.

7. Disables animated wallpapers

Dynamic wallpapers for the home screen and lock screen contain objects that move in the background, constantly repeating, adding life to your iPhone.

With the power saving mode enabled, the animated motion will stop and you will have a temporary still wallpaper until the power saving mode is disabled. The still image is the last frame viewed in the animated sequence, so it may look different each time you turn on power saving mode.

Live wallpapers (and live photos) are not affected as you need to manually activate motion. Wallpapers that update in real time on lock screens in iOS 16, such as Weather or Astronomy, are also unaffected.

8. Pauses iCloud Photo Sync

If you’re using iCloud Photos, your iPhone is constantly trying to sync photos and videos across all of your iCloud devices. When power saving mode is enabled, the synchronization process stops. Any new pictures you take or upload will only remain on your iPhone until power saving mode is turned off. In Photos, you might see something like “Download paused for [#] items”with a “Manage”button that will take you to the power saving mode settings. When power saving mode is disabled, sync should resume normally.

9. Reduce background app refresh

Background app refresh allows apps to check for new data even if they are not currently active. If you’ve just used the app, it will run for a short time after you exit it, but then go into a pending state where it can’t do anything unless background app refresh is enabled.

Not all apps offer this feature, but if they do, they will be able to check for updates and new content long after you last used them. When there’s something useful that the app thinks you want to know about, such as a sudden change in the weather, you’ll get a notification alerting you to that important information.

You can enable or disable background app refresh system-wide via Settings -> General -> Background App Refresh. You’ll also see a list of all the apps that will update on their own, each with a toggle so you can enable or disable your update settings on a per-app basis.

Background app refresh is disabled system-wide when low power mode is enabled, so none of the important notifications will come through. When power saving mode is disabled, all of your background app refresh settings revert to their previous state.

10. Disables automatic downloads

The auto-download options for the App Store, Books, and Music in Settings let you automatically download apps or media to your iPhone when you purchase or install it on another of your iCloud-connected devices. You can also set all your apps to update automatically, which is even more useful.

When you turn on power saving mode, automatic downloads for apps, app updates, and books are disabled (but not for music for some reason), and these restrictions will be lifted when you deactivate power saving mode.

11. Disable autoplay video

There’s also a Video Autoplay option in the App Store settings that automatically plays videos to preview apps in the App Store. If enabled, it will temporarily turn off every time you turn on low power mode, and re-enable app video previews automatically when you turn off low power mode.

12. Decreases the refresh rate

When viewing content in Safari and elsewhere on iPhone 13 Pro or Pro Max, your display shows a 120Hz refresh rate at 120fps. When power saving mode is enabled, the refresh rate will not exceed 60Hz at 60fps in many areas. All other iPhone models use 60Hz at 60fps and drop to 30Hz at 30fps when low power mode is enabled.

So if you’re browsing the web and notice that everything is a bit choppy, low power mode might be the culprit. You can check the refresh rate with a web tool like testufo.com.

13. Reduces CPU and GPU performance

In addition to dropping the refresh rate, iOS slows down the overall CPU and GPU performance of your iPhone when Low Power Mode is enabled. Thus, you may notice that your iPhone may not be as fast and the graphics may not be as smooth. You can test the features of your iPhone with a benchmarking app like GeekBench.

14. Suspends discretionary and background activities

I have already mentioned several background processes that are affected by the power saving mode. However, there are other things you may notice, such as the lack of updates for location data and network activity. However, not all apps will be bound to low power mode, and apps that do will behave differently.