How To: Use Low Power mode on iOS 9 and how it works

iOS 9’s new Low Power mode can come quite handy when your iPhone’s battery is running low (yes, it’s only available for iPhones) and keep it going for a while longer, until you can get to a convenient power source to plug it in.

Whenever your phone gets to 20 percent battery it will prompt you to turn on the Low Power mode, but it doesn’t mean you can’t enable the feature earlier, as a preventive measure (more on that later).

How Low Power mode works

The feature’s name is self explanatory – it obviously reconfigures your iPhone to save battery power – but only to a certain extent. What Low Power mode does, is it changes some of your phone’s settings to reduce battery consumption, such as turning of auto-fetching of new mail, automatically locking the phone and turning off its screen faster, lowering the screen brightness and others.

But Low Power mode is a bit more complex than that. Apps can also detect when its turned on, and as a result disable battery-draining features such as animations. Among other things Low Power mode turns off, are animated wallpapers, motion effects, background activities, networking and it even lowers the performance of your iPhone’s CPU and GPU. Yes, this will make your phone slower, but it won’t be so battery-hungry.

How to enable/disable Low Power mode

As I already mentioned and you probably know this by now, if you’ve been using iOS 9 on your iPhone for a while, a prompt to turn on Low Power mode automatically appears when your phone has 20% battery power left. You can enable the feature by tapping on Continue after or Cancel if you don’t need it.

iOS 9 - Low Power mode Settings

Nevertheless, Low Power mode can be turned on manually, at any time. You can do this from the Settings app by opening the Battery menu. From there simple toggle on the “Low Power Mode” slider. Just to remind you the feature is enabled, for as long as it’s turned on, the battery icon in the status bar will be yellow.

Low Power mode prompt

When your iPhone charge level reaches 80%, Low Power mode will be automatically disabled. So if you want to turn it back on the next day, you’ll have to do it manually.

How to tweak some of the settings used by Low Power mode

Low Power mode has some limitations: you can’t keep it turned on permanently and you can’t exactly customize its behavior. What you can do is tweak some of the settings it uses and get better battery life for your iPhone at all times.

Here are some settings you can tweak on your iPhone for extended battery life:

Mail fetching – Email accounts set to “fetch” new emails require your phone to automatically verify them at regular intervals and download new mail if available. Obviously this feature can use quite a bit of battery power. For the sake of saving some battery you can either set your email accounts to “push” new mail or turn this off completely and verify your email manually, although the latter option won’t send you any email notifications either.

Auto-lock timeout – Go to your Settings app, tap on General and then on Auto-Lock to setup how fast your iPhone automatically turns of the screen and locks itself. If you want the battery to last longer it’s always wise to set a short period of time for Auto-lock timeout – 30 seconds seems decent enough.

Screen brightness – For the sake of your iPhone’s battery the best setting would be to turn on auto-brightness. You can find it in the settings app under the Display & Brightness category. It will ensure your screen remains readable regardless of the current lighting conditions but without keeping the brightness too high when it’s unnecessary. And the screen is a notorious battery hog for any smartphone, not just for iPhones.

Background refresh – Disabling this feature for an app will prevent it from automatically refreshing in the background. You may need background refresh on for some apps, but surely you have others for which the feature doesn’t need to be enabled. To tweak it, open the Settings app and go to General -> Background App Refresh. From here, you can either disable the feature completely or customize it on a per app basis.

How should you use Low Power mode?

I know this might seem obvious for some of you, but turning the feature on just when your iPhone’s battery is hanging by a thread is just one way to use it. I think Low Power mode can be used successfully to make a phone’s battery last longer and as a result enabled as soon as you leave the house with your fully charged iPhone.

Say you know today you’re going to be on the road, or generally in places where you can’t recharge your phone. Enabling Low Power mode even when your iPhone’s battery level is full or at least high can drastically reduce battery usage. And yes, your apps won’t refresh as often, some animations will be disabled, your phone’s performance will be a little lower but you’ll still be able to perform most usual tasks.

If you’re curious how this works, check out Matt Birchler’s experiment. He tracked battery performance for several days in both Low Power and normal modes so you can see how the battery saving feature can help a great deal to make your phone last all day when it wouldn’t have been possible otherwise.

Have you ever tried going for a full day with Low Power mode turned on? How did that work? Let us know in the comments section below or drop us a line on Facebook, Twitter or Google+.