Does Quitting Apps Save iPhone Battery Life?
The short answer is: no, quitting apps doesn't save battery life. This may be surprising to people who believe in this technique, but it's true.
How do we know? Apple says so.
An iPhone user emailed Apple CEO Tim Cook to ask this very question in March 2016. Cook didn't respond, but Craig Federighi, who heads up Apple's iOS division did. He told the customer that quitting apps doesn't improve battery life. If anyone would know the answer to this question for certain, it's the person in charge of the iOS.
So, quitting apps does not help get your iPhone better battery life. That's simple. But why this is the case is more complex, and explains why the technique isn't helpful.
How Multitasking Works on iPhone
The idea that quitting apps saves battery likely comes from seeing that the iPhone seems to be running a lot of apps all at once and the mistaken belief that those apps must all be using battery.
If you've ever double clicked your iPhone's Home button and swiped side to side through the apps, you've probably been surprised to see how many apps appear to be running.
The apps presented here are ones you've used recently or may be using in the background right now (you might be listening to the Music app while you browse the web, for example).
Despite what you may think, almost none of these apps is using battery life. To understand why, you need to understand multitasking on the iPhone and the five states of iPhone apps.
According to Apple, every iPhone app on your phone exists in one of these states:
Not Running—In this state, the app isn't running or was automatically quit by the iOS
Inactive—This is a brief transitional state, generally only used when switching from one app to another
Active—This is your primary app, the one you're using right now
Background—Running behind the scenes. Most apps can't run in the background, but apps that play music, provide GPS/mapping features, and a few other classes of app can work in the background
Suspended—The app exists in the background, but it's not actually running.
The only two of these five states that use battery life are Active and Background. So, just because you see an app when you double click the Home button doesn't mean it's actually using battery life. (For a more technical explanation of what happens to apps when they're suspended, and how that proves that they don't use battery life, check out this article and video.)
Can Quitting Apps Actually Harm iPhone Battery Life?
How's this for irony? People quit their apps in order to get more battery life, but doing this may actually cause them to get less life from their batteries.
The reason for this has to do with how much power it takes to launch an app.
Launching an app that hasn't been running and doesn't show up your multitasking view takes more power than restarting an app that's just been suspended since you used it last. Think of it like your car on a cold morning. When you first try to start it, it may take a little longer to get going. But once the engine is warm, the next time you turn the key, the car starts up faster.
The amount of extra battery life you use to launch apps that aren't running probably isn't a huge difference, but it's still doing the opposite of what you want.
When Quitting Apps Is a Good Idea
Just because quitting apps isn't good for saving battery doesn't mean you should never do it. There are a number of situations in which closing apps is the best thing to do, including when:
- App is malfunctioning—If app an is causing problems for your phone or not responding, quitting is often the best way to fix it
- It's using background data—Want to make sure an app is only using your data when you expect it? Quitting the app ensures it won't use data in the background (this also requires that Background App Refresh be turned off).