What are wakelocks, how they affect the battery life of your Android device, and how to "Greenify" them

Have you ever gone to bed with your phone's battery well over 50% and woken up to find out that it has depleted overnight and the device has switched itself off? There are several causes for this abnormal behavior, and among the biggest culprits are the unwanted system wakelocks.

So, what exactly are these? Wakelocks are power-managing software mechanisms, which make sure that your Android device doesn't go into deep sleep (which is the state that you should strive for), because a given app needs to use your system resources. There are several types of wakelocks:

Normally, wakelocks shouldn't use a large amount of your system resources when you are not using your device, as it should be in a state of deep sleep. Although wakelocks on Android are not necessarily a bad thing, minimizing these should be the priority of any Android power user who's on the hunt for better battery life.

Unfortunately, some poorly-coded, malicious, or simply buggy apps might create an abnormal amount of undesirable wakelocks. Other apps require constant Internet access in order to operate in a normal fashion - Facebook and Messenger are probably the most popular representatives. They persistently request information from the web (the so-called "polling" for new events), which is causing subsequent wakelocks.

In other cases, an update to a given app can also cause certain issues, which usually result in partial wakelocks. The latter keep your CPU constantly humming in the background, sometimes without your knowledge, and prevent your device from "going to sleep". That's a pretty substantial prerequisite for anomalous battery drain. Thus, it is advisable to regularly monitor the wakelocks on your device and see which of your apps go harsh on our system's resources.

So, we'll show you the ropes on how to do this. First, we should find out what app or process might be causing these wakelocks.

Now, after we've found out which app is causing the device to stay awake and discharge its battery at the same time, we can do several things in order to get rid of the issue. As we mentioned before, uninstalling the app is one way to do this, but let's face it - that's a pretty harsh and barbaric method, isn't it? One of the more sophisticated, yet elegant ones is by using Greenify.

This amazing little tool that allows you to put a given app in "hibernation" when you are not using it. What Greenify does is simple - it literally hides the hibernated app from the prying eyes of Android, preventing it from polling, using your hardware resources, and most importantly, causing any partial or full wakelocks. The app will only run if you open it. Neat, right? 

Greenify can work on non-rooted devices, but for best results, your Android smartphone should be rooted. You'll also need a running Xposed framework if you want to make use of some of Greenify's experimental features. Note that the free version of Greenify only allows you to hibernate non-system apps, while the premium one has no such restrictions. You should know that it is not advisable to use this tool on certain system apps that you rely on or know nothing about, as this can make your system pretty unstable.

With that being said, let's see how one should put Greenify to good use!

And that's it! Don't forget to check out some of our essential tips & tricks on how to save even more of your battery's juice!

reference: Android Developers (1), (2), XDA



1. justsayit

Posts: 256; Member since: May 09, 2013

lol just go to dev option,then check "Dont keep activities" or somethings like that

3. TylerGrunter

Posts: 1544; Member since: Feb 16, 2012

That's a bad practice! Using that kills the apps as soon as you are out, which deletes all the information for the session. Doing that slows your phone a lot as it needs to get the information again next time you go into the app. Also killing services is a bad practice, as they restart themselves afterwards, so you spend even MORE battery doing that. In fact I have been using "Geenify" and the "Wakelock Detector" every time I have issues with the battery, and the comibitaion (if you are root) works like a charm.

12. justsayit

Posts: 256; Member since: May 09, 2013

but my g2,i enable this function and left it overnight,no battery used LoL i didnot bluff

13. justsayit

Posts: 256; Member since: May 09, 2013

yup it did slow down phone a little bit only notice when opening an apps,just not as snappy but still fast geenify need to root right? i still didnt want to root yet maybe after lg stop giving g2 update,then i root

15. Anonn

Posts: 230; Member since: Jun 04, 2014

Greenify does NOT require Root now

4. TylerGrunter

Posts: 1544; Member since: Feb 16, 2012

14. justsayit

Posts: 256; Member since: May 09, 2013

or limit background process

5. joey_sfb

Posts: 6794; Member since: Mar 29, 2012

I get by the large part of my Android experience without these tools. However, once i learn to use them i am able to control every aspect of my Android usage experience.

6. DavvyGhotra

Posts: 13; Member since: Jul 24, 2014

i m allready getting 1.5 day on htc one m7 with high usage and in my opinion A app can't save battery it will consume even more !

7. murali_v_2000

Posts: 36; Member since: Jan 31, 2012

6 days since full charge and still at 52% - Note 3, low usage. Used every possible power save option that there is (incl undervolt, greenify etc).

8. vishalaestro

Posts: 81; Member since: Dec 08, 2013

does hibernating apps like whatsapp makes delivering messages in a late manner?

10. SellPhones82

Posts: 569; Member since: Dec 11, 2008

I would test it, but pretty sure the messages will not come through until you open the app. I hibernate the FB Messaging app as it was waking my phone up all the time and I only get notifications when it's not hibernating. Never tested it with whatsapp though.

9. harigrg33

Posts: 188; Member since: May 20, 2013

I install this app but it says 'kitkat need root access as permission changes by google' and my phone is not rooted.

11. SellPhones82

Posts: 569; Member since: Dec 11, 2008

You can try this if you don't want to root. However, I'd think rooting would be an easier option. https://docs.google.com/presentation/d/1r3VlhZIZVSufZlAeICJet6QBtyAF7z06_ysl1kUKME4/edit#slide=id.p

16. Anonn

Posts: 230; Member since: Jun 04, 2014

Try "My Battery Drain Analyser"https://play.google.com/store/apps/details?id=com.WazaBe.android.BatteryDrain It can detect abnormal activities

17. cyberjet

Posts: 3; Member since: Jul 25, 2015

I Just purchased a Redmi 2 From Snapdeal.com in Apr, 2015 I Faced problem of heating in just the stand by mode after installing Whats App, MXPlayer etc., Phone generates heat at the back and auto swich off Due to the above problem i submits the mobile at the Janak Puri Dist,: HCL Touch (West) Address: G-5 (II), Shop No.5/126 & 5/127, Janak Place, Distt. Centre, Janakpuri, New Delhi Hours of Operation: Monday to Saturday, 10:00-18:00 Service Center Phone Number: 011- 25615338 on 11/07/2015 and they return it on 24/07/2015 after replacing the bettery But it still have the same problem, due to that i visit the service center again on 25/07/2015 and explained the problem, They ask to re-submits the phone for 2 weeks. I am unable to re-submits it for 2 weeks again

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