When you enable Low Power Mode on your iPhone, it's not always clear what measures it's taking to reduce battery drain and conserve power. Changes to energy-hungry features you use daily may be immediately noticeable, but some things you use frequently may be disabled or reduced without any apparent indicators.

Your iPhone will ask if you want to turn on Low Power Mode whenever your battery hits 20% and 10% power remaining, but it's not mandatory. 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 by using specific triggers via the Shortcuts app.

No matter how you activate it, Low Power Mode will enact specific energy-saving measures to ensure your battery lasts longer until you have time to charge it. But you may not want some of the features that are disabled or reduced affected, which would help you decide on whether Low Power Mode is needed or not. So knowing what's going on can be important.

Also, by understanding all of the tasks temporarily affected by Low Power Mode, you'll be able to use it whenever it helps curb a particular feature — even if your battery is charged enough.

No matter why you use Low Power Mode, it will automatically disable itself when your iPhone's battery level rises to an 80% or higher charge. Some of the features and tasks listed below may work as usual with Low Power Mode on when your iPhone's battery is 80% or higher.

The iPhone 12 series models, iPhone 13 series models, and iPhone SE (3rd Generation) all have 5G capabilities. You can get incredible speeds on your carrier's 5G network, but not when you turn on Low Power Mode.

Lower Power Mode disables 5G on your iPhone, pushing you to a 4G or LTE network until you turn off the battery-saving mode. However, video streaming and large downloads should continue to use 5G because it's more efficient than using 4G or LTE for those tasks.

5G Standalone is the superior 5G network since it has a 5G network core that makes it self-sufficient, and it's not available from every carrier or mobile virtual network operator. T-Mobile is one of the few carriers that offer a standalone service. Non-standalone 5G networks, which are more common, have a 4G LTE network core, giving you some benefits of 5G but not everything that true 5G is capable of.

Low Power Mode disables 5G Standalone network access, but only on the 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 5G Standalone because the entire connection is severed, so they'll fall back on non-standalone 5G networks.

Your iPhone's display brightness can drain your battery if you always max it out. You can help reduce the drain by enabling Auto-Brightness or adjusting the brightness from Control Center or Settings, but Low Power Mode also helps.

Whenever you turn Low Power Mode on, your display will dim slightly, and you might not even notice when it happens unless you look for it specifically. Your brightness controls will remain unchanged because iOS is not actually adjusting those when Low Power Mode is on.

Instead, the Reduce White Point feature is the most likely culprit, which lessens the intensity of the whites on the screen, lowering the overall brightness. The Reduce White Point slider only goes from 25% to 100%, so there's 25% for Apple to play around with for Low Power Mode.

When Low Power Mode is on, you'll see the display dim whether you already have Reduce White Point or Auto-Brightness activated or not.

Email accounts in the Mail app can either push new emails to you when they hit the servers, fetch new emails at intervals you set, or manually load new emails whenever you view the account or refresh its page. This is also true for other data types in other apps, such as calendars, notes, contacts, and reminders connected to your email accounts. You can find these preferences via Settings –> Mail –> Accounts –> Fetch New Data.

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

By default, iOS makes it so that your display will sleep after 30 seconds of inactivity. If you disabled Auto-Lock or set it to 1, 2, 3, 4, or 5 minutes, Low Power Mode would change your display's sleep time back to 30 seconds until it's deactivated.

Perspective Zoom moves your home screen wallpaper and interface elements based on movement 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 the parallax effect.

With Low Power Mode on, Perspective Zoom is disabled, so there will be no background or foreground movement on the home screen until Low Power Mode is turned off.

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 in-app animations, etc., will still animate with Low Power Mode on. Toggling on Reduce Motion in Settings –> Accessibility –> Motion will also disable Perspective Zoom, but it will also affect the other motion effects I just mentioned.

Dynamic wallpapers for the home and lock screens contain objects that move around in the background, continuously looping, adding life to your iPhone.

With Low Power Mode enabled, the animated movement will stop, and you'll have a temporary still wallpaper until Low Power Mode is disabled. The still image is the last-viewed frame in the animated sequence, so it could look different every time you turn on Low Power Mode.

Live wallpapers (and Live Photos) are not affected since you have to activate the movement manually. Wallpapers that update in real time on your lock screens in iOS 16, like the Weather or Astronomy ones, are also not affected.

If you use iCloud Photos, your iPhone constantly tries to sync the photos and videos on all your devices to iCloud. When you turn on Low Power Mode, the syncing process halts. Any new images you take or download will remain only on your iPhone until Low Power Mode is disabled. In Photos, you may see something like "Upload Paused for [#] Items" with a "Manage" button that takes you to Low Power Mode's settings. When you disable Low Power Mode, syncing should resume as normal.

Background App Refresh lets apps check for new data even when they aren't currently the active app. If you just used the app, it'd run for a short time after leaving it, but it will then enter a suspended state where it can't do anything unless Background App Refresh is enabled.

Not all apps offer this ability, but if they do, they'll be able to check for updates and new content long after you last used them. When there's something useful the app thinks you'll want to know about, like a drastic weather change, you'll get a notification alerting you of this critical 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 refresh by themselves, each of which has a toggle so you can enable or disable your refresh settings app by app.

Background App Refresh is turned off system-wide when Low Power Mode is enabled, so none of the important notifications will come through. When Low Power Mode is disabled, all your Background App Refresh preferences return to how they were.

The Automatic Downloads preferences for App Store, Books, and Music in Settings allow apps or media to download onto your iPhone automatically when purchased or installed on another of your iCloud-connected devices. You can also make all of your apps auto-update, which is even more helpful.

When you turn on Low Power Mode, Automatic Downloads for Apps, App Updates, and Books are disabled (but not Music for some reason), and those restrictions will be lifted whenever Low Power Mode is deactivated.

Also in the App Store settings is an option called Video Autoplay that automatically plays app preview videos in the App Store. If enabled, it will temporarily disable itself whenever you turn on Low Power Mode and reenable auto-playing app video previews when you shut down Low Power Mode.

When viewing content in Safari and other places on an iPhone 13 Pro or Pro Max, your display shows you a 120 Hz refresh rate at 120 frames per second. When Low Power Mode is on, the refresh rate will not exceed 60 Hz at 60 fps in many areas. All other iPhone models use 60 Hz at 60 fps and drop to 30 Hz at 30 fps when Lower Power Mode is on.

So if you're browsing the web and notice things are a little bit choppy, Low Power Mode may be the culprit. You can test your refresh rate with a web tool like testufo.com.

Aside from the refresh rate drop, iOS reduces your iPhone's overall CPU and GPU performance with Low Power Mode activated. So you may notice that your iPhone may not be as speedy, and the graphics may not be as smooth. You can test the specifics of your iPhone using a benchmarking app like GeekBench.

I've already mentioned a few background processes affected by Low Power Mode. Still, there are other things you may notice, such as missing updates for location data and networking activity. Not all apps will tie into Low Power Mode, though, and apps that do will do things differently.

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