Closing applications actually drains battery (Still under testing)

[Ser Aphim]

A fellow member Ardchoille posted an article about how to save battery life. The step that really caught my eye was "Closing apps actually drains battery life.". That kept me thinking though, how could leaving apps open save battery life? When we all know, that force closing apps actually saves battery life. Apparently is was from a former employee from the genius bar.

I found a few articles about it. Many articles support the theory. Here is what LifeHacker say's about this:

Yes, it does shut down the app, but what you don't know is that you are actually making your battery life worse if you do this on a regular basis. Let me tell you why.

By closing the app, you take the app out of the phone's RAM . While you think this may be what you want to do, it's not. When you open that same app again the next time you need it, your device has to load it back into memory all over again. All of that loading and unloading puts more stress on your device than just leaving it alone. Plus, iOS closes apps automatically as it needs more memory, so you're doing something your device is already doing for you. You are meant to be the user of your device, not the janitor.

The truth is, those apps in your multitasking menu are not running in the background at all: iOS freezes them where you last left the app so that it's ready to go if you go back. Unless you have enabled Background App Refresh, your apps are not allowed to run in the background unless they are playing music, using location services, recording audio, or the sneakiest of them all: checking for incoming VOIP calls , like Skype. All of these exceptions, besides the latter, will put an icon next to your battery icon to alert you it is running in the background.

There was a comment saying that mobile multitasking isn't like multitasking in a computer, where running multiple programs will slow down the device. In iOS, when you exit an app, it automatically "Freezes it". iOS already closes apps automatically to free up RAM. Force closing apps and opening them again can cause stress and that stress could drain battery life.

I'm not even sure if I should follow this. But I sure hell will test this!

 

[ardchoille]

This is how it was explained to me:

When you exit an app some of the app elements are cached so that the app will start up faster when it's needed again. The app isn't actually using system resources so it's safe to leave it cached, the system will free up memory as needed. Force closing an app, on the other hand, removes these cached elements so starting the app up again causes the system to have to restart the app "from scratch", and that uses more system resources than if the app were allowed to remain cached. It's easier on the system and battery if the user avoids force closing apps, except in the case of a problematic app, and allows the system to take care of the house cleaning. That former genius bar employee was spot on.

I really think this is a *nix thing because Linux does the same thing. And, from what I understand, iOS is based on a variant of BSD. When it comes to a *nix system, unused ram is wasted ram.

 

[s2mikey]

Hmmm.... Interesting concept. It kind of makes sense. But, somehow, I'm not sold completely. I've been so happy with battery life that I probably wouldn't notice anyways.

 

[Ser Aphim]

Hmmm.... Interesting concept. It kind of makes sense. But, somehow, I'm not sold completely. I've been so happy with battery life that I probably wouldn't notice anyways.

Yeh I'm not sold either but I got to try this out for myself. If this gets to 12 hours, when the total I got is 10 or 11 hours, or even surpasses 12 hours I may be impressed.

I noticed that opening apps is now faster. Seems like even if my battery life stays the same it will be faster for me to open apps

 

[ardchoille]

Yeh I'm not sold either but I got to try this out for myself. If this gets to 12 hours, when the total I got is 10 or 11 hours, or even surpasses 12 hours I may be impressed.

I noticed that opening apps is now faster. Seems like even if my battery life stays the same it will be faster for me to open apps

Yes, opening previously used apps will always be faster, so long as you don't force close them, that's the point of caching them - speed and less system resources required.

 

[The OB]

There may be some substance to what both you guys (above) are saying.
The following wisdom from Apple is saying that it's typically unnecessary to force an app to close as it seems to be sitting in a "suspended" state, implying not all of that app is there working in the background.
http://support.apple.com/kb/ht5137

And considering this background working (multitasking if you like) we further hear from Apple that the iPad will do its own thing to "lessen the effect on battery life" by scheduling its own background refreshing "for efficient times" like when connected to WiFi, or to a power source, "or being actively used"
Bit of reading, but you'll find that here:
http://support.apple.com/kb/HT4211

And of course there are a lot of "experts" in this world, but this one seems to make some sense also:
http://www.imore.com/tipb-answers-close-apps-multitasking-dock

So, again, some interesting points raised by you guys. Thanks
Andrew


Sent from Oz using Tapatalk

 

[Ser Aphim]

There may be some substance to what both you guys (above) are saying.
The following wisdom from Apple is saying that it's typically unnecessary to force an app to close as it seems to be sitting in a "suspended" state, implying not all of that app is there working in the background.
iOS: Force an app to close

And considering this background working (multitasking if you like) we further hear from Apple that the iPad will do its own thing to "lessen the effect on battery life" by scheduling its own background refreshing "for efficient times" like when connected to WiFi, or to a power source, "or being actively used"
Bit of reading, but you'll find that here:
iOS: Understanding multitasking

And of course there are a lot of "experts" in this world, but this one seems to make some sense also:
TiPb Answers: No, you don't need to kill all the apps in your multitasking dock | iMore

So, again, some interesting points raised by you guys. Thanks
Andrew


Sent from Oz using Tapatalk

Just in case someone says "So whats the point of force closing apps?!"

So you can fix it when you are having problem with the app, as stated in the first link.

 

[The OB]

Just in case someone says "So whats the point of force closing apps?!"

So you can fix it when you are having problem with the app, as stated in the first link.

Yeah, I've had a tendency to force close all apps each night thinking this "cleans" up stuff. But it seems the iPad is designed to save us that work and itself looks after that side of it when necessary. Of course, best to force close an app that "misbehaves" so it can be reinstated afresh when next used, IMO.
Andrew


Sent from Oz using Tapatalk

 

[Ser Aphim]

So the only way to truly make an app run in the background is by turning in background app refresh.

 

[The OB]

So the only way to truly make an app run in the background is by turning in background app refresh.

I think that's right. You can choose which apps will refresh and which apps the system will remove to tidy up the system, apparently after a period of time by Settings>General and choose which apps to refresh.
Andrew


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[Ser Aphim]

Basically I thought Facebook, and other social networking app or apps that downloads files coukd drain battery. But then it turns out that it will onky drain battery when there is an activity going on. Like posting photo's, videos, and other attachments. Until the activity is done, it would still remain open. It would close after the activity is finished. So no need to worry about that :/

Here are the exceptions I found on articles I found that needs to be forced closed:

Streaming audio like Pandora. This can keep playing in the background but if you pause or turn off the music, it ends. No need to force quit these apps either. (Just check to make sure volume isn't off, otherwise you might as well pause the music...)
VoIP apps like Skype. These can keep running in the background and Skype especially can drain your battery. You can close Skype or other VoIP apps if you aren't actually waiting for a call.
Turn-by-turn navigation like TomTom. These can stay in the background and give you location and voice instructions and if you don't need it anymore you can quit it to spare your battery the aGPS hit
Task completion, like finishing uploading a picture to Facebook or downloading your Twitter stream. These will automatically close when the activity is finished. Even if the activity doesn't finish they'll close after a short period of time anyway. So again, unless you really want to stop what they're doing there's not need to close them.

So keep that in mind.

 

[ardchoille]

I just performed a little test with Safari to show myself that apps don't typically continue working in the background after you press the home button.

1. Open Safari
2. Choose a website that hasn't been visited since cookies and data were last cleared
3. As soon as the website begins to load, imediately press the home button
4. Wait a minute or two and double-press the home button to view Safari in the multitasking view

I noticed that the website still hadn't fully loaded (Safari was "frozen" due to being sent to the background), proof that Safari didn't continue loading a website in the background. I left it like that (multitasking view) for another minute and then opened Safari again to find the website was still loading.

 

[Ser Aphim]

I just performed a little test with Safari to show myself that apps don't typically continue working in the background after you press the home button.

1. Open Safari
2. Choose a website that hasn't been visited since cookies and data were last cleared
3. As soon as the website begins to load, imediately press the home button
4. Wait a minute or two and double-press the home button to view Safari in the multitasking view

I noticed that the website still hadn't fully loaded (Safari was "frozen" due to being sent to the background), proof that Safari didn't continue loading a website in the background. I left it like that (multitasking view) for another minute and then opened Safari again to find the website was still loading.

Yeh I notice that too. I didn't care about it at first but right now that is helping me

 

[The OB]

I just performed a little test with Safari to show myself that apps don't typically continue working in the background after you press the home button.

1. Open Safari
2. Choose a website that hasn't been visited since cookies and data were last cleared
3. As soon as the website begins to load, imediately press the home button
4. Wait a minute or two and double-press the home button to view Safari in the multitasking view

I noticed that the website still hadn't fully loaded (Safari was "frozen" due to being sent to the background), proof that Safari didn't continue loading a website in the background. I left it like that (multitasking view) for another minute and then opened Safari again to find the website was still loading.

Yes that's interesting as it seems the system leaves a sort of "key" there so it "remembers" where it left off with a task. The same happens when you stop reading in a Book Mark or reading list and it returns to the same page that you were reading.
Andrew


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[ardchoille]

Yes that's interesting as it seems the system leaves a sort of "key" there so it "remembers" where it left off with a task. The same happens when you stop reading in a Book Mark or reading list and it returns to the same page that you were reading.
Andrew


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Yep, that seems to prove that apps don't just go about their merry business when they are sent to the background.