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battery drainage

J

jabbb

Newbie
Hello guys,

I'm new here and I'm new for android and smartphones in general.
I bought me s4 mini few months ago and now few days ago it started suffering of major battery drainage. I downloaded betterbatterystats and wakelock detector and I could see that "suspend_backoff" was keeping my phone awake all the time, but I couldn't pinpoint which was the problem causing app so I decided to reset the phone.
I did that yesterday and now I've been watching the info from those aforementioned apps and I noticed "deleted_wake_locks" is very high on the list.
I'm not sure but maybe the reason for this is because I had most of my apps on a sd card before resetting the phone, now I unmounted and removed it and I'll observe if my phone goes to deepsleep.

Do you think by formatting my sd card it will solve the deleted_wake_locks drainage?

One peculiar fact: betterbatterystats gives 0 seconds to "deleted_wake_locks" while wakelock detector gives it 5 minutes.
 
Also "suspend_backoff" rose its ugly head again, it has kept my phone awake for the last 1h.

Is there anyone who know what I should do with this problem?

ps. after factory reseting my phone I haven't downloaded any apps (except bbs and wld) and I've tried to disable all the automatic functions like "autosync"
 
Hi jabbb, and welcome to the board :)

From my understanding, the "suspend_backoff" wakelock is used when there are a lot of sleep/wake cycles requested in quick succession - rather than bouncing between wake/sleep states 10 times in 50ms (or whatever the standard is - not sure on that), the phone will use the suspend_backoff wakelock to just keep it awake for those 50ms instead.

That information isn't particularly helpful in tracking down the actual battery drain, but it will hopefully at least help explain what's going on.

How's your usage look under Settings > Battery? Detailed screenshots would be great. :thumbup:
 
Hi codesplice
Unfortunately I'm not sure how to make a screen shot, but android os is the second in the list of battery consumption with 25% right after screen with 27%. Before factory reset the os was takin more than 50%
 
You generally can take a screenshot by pressing the Volume-Down and Power buttons at the same time - hold both for about two seconds.

It would be very helpful if you could share a picture of your Battery overview page, the History Details page (tap the graph at the top of the Battery screen), and the Use Details for some of the top listings (tap the app/component name on the Battery screen). :thumbup:
 
Click "show" for screenshots
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Interesting that the Use Details screen shows Android OS holding the phone awake for 7.5 hours, but the Awake line on the History Details screen doesn't seem to match. :hmmmm2:

Maybe some screenshots from BBS / WLD would be helpful as well?
 
Thanks for posting those. I don't really see anything out of the ordinary - in fact, I think those stats look pretty good. Your phone was only held awake for just a few minutes over the course of almost 10 hours; I don't think wakelocks are killing you. :)

That said, I don't think that you should be dropping ~1.2% per hour while in standby. Any chance you could try letting the phone sleep in Airplane Mode tonight? I have a hunch that it may be spending a lot of juice trying to maintain a network connection. Running in Airplane Mode should help to confirm that, and we can then try to look into what might be causing it - though, unfortunately, that's often out of our hands.
 
Ok I had my phone in airplane mode for the night and the battery consumption was minimum...maybe 2~3%. I must say that the phone started behaving like this since I started writing here. Now the OS consumption is only 6%, before it was 25% and it seemed "suspend_backoff" hogging all the juices, at the moment it's little bit better
ObBjaMA.png

Is it normal to have suspend_backoff always so high in the list?
 
So that does sound like the overnight drain is probably related to trying to maintain a network connection - in other words, it's pretty normal and there's not a lot to be done about it.

I wouldn't worry too much about the suspend_backoff wakelock - when it appears, it's usually because it's more battery-friendly to just keep the phone awake instead of bouncing rapidly between wake and sleep repeatedly.

I also found some info on that pm8921_eoc wakelock as well:
Its about end of charging(eoc) thing. pm8921 is our charger driver for many qualcomm soc.
This wakelock starts when your battery charges to more than 90% and, charging current is reduced to trickle charge. And you see this wakelock because when your phone is connected to charger even after being full charged, it is identified as full and its in "not charging" state even when connected. And batterystatus app starts picking wakeocks as soon as android report "not charging" state, or I may say it starts reporting as soon as it finishes charging.

Anyways nothing to worry about it, as when you are connected to AC or USB, your device is never in deepsleep. This wakelock does not effect battery, as its not waking up device from deepsleep.
Click to expand...
 
OK, but if there's excessive amount of suspend_backoff it means it's draining the battery. Is there a way to find out which apps are related to suspend_backoff.

Also now I reattached my sd card to the phone and leave it lay on the table for some hours to see if there's any difference.

I think I'll start downloading apps one by one and see which one is the cause for battery drainage.

ps. should I keep all my apps up to date? even the ones I never use?
 
jabbb said:
OK, but if there's excessive amount of suspend_backoff it means it's draining the battery. Is there a way to find out which apps are related to suspend_backoff.
Click to expand...

If suspend_backoff wasn't used, I think you'd still have about the same amount of "held awake" time - it would just be distributed across other wakelock sources. I don't think there's a way to find out what app may be causing that, but my guess is that it's actually something within the OS.

I think I'll start downloading apps one by one and see which one is the cause for battery drainage.
Click to expand...
:thumbup:

ps. should I keep all my apps up to date? even the ones I never use?
Click to expand...

I would. Updates usually include bugfixes, which sometimes will include fixes for unnecessary battery drain.
 
ok let's hope it just doesn't keeping my phone awake and rise OS battery drainage.
Anyway the weirdest thing is that I didn't do anything to the phone after starting the thread and now it seems the phone fixed it self, even now after putting the sd card the battery consumption % are the same as before.

You think 360 security - av could cause reasonable drainage? and are av apps necessary in any case?

About the app updates: but aren't you gonna eventually fill up your phone memory if you keep downloading the updates?
 
jabbb said:
ok let's hope it just doesn't keeping my phone awake and rise OS battery drainage.
Anyway the weirdest thing is that I didn't do anything to the phone after starting the thread and now it seems the phone fixed it self, even now after putting the sd card the battery consumption % are the same as before.
Click to expand...

Sometimes a phone just needs a bit of time to "settle in" - particularly since you just recently did the factory reset (right?).

You think 360 security - av could cause reasonable drainage? and are av apps necessary in any case?
Click to expand...

AV apps really aren't necessary on Android anymore. Google already scans all the apps available in the Play Store; they then started scanning apps that you install from outside the Play Store (enable this at Settings > Security > Verify apps); and most recently they also implemented a lightweight background scan that watches for malicious activity even after an application is installed.

The only real reason that I've ever used an antivirus/security application on Android was for the anti-theft functions (remote wipe, device locate, etc), but that's now included by default with Android Device Manager anyway. My battery thanked me once I got rid of all the AV stuff ;)

About the app updates: but aren't you gonna eventually fill up your phone memory if you keep downloading the updates?
Click to expand...

Not for most apps. The updates either replace the already-installed package, or else it's a "delta" update which only patches a portion of the app. The one exception is for system applications (those which came pre-installed). Since those applications are actually installed on the protected /system partition, updates are unable to replace them. Those updates will take up some amount of space - but it usually won't be much. If it's an app that you truly never use, you can disable it (Settings > Applications) which will also prevent it from installing updates.
 
by disabling you mean turning them off or force stopping?..I've seen apps restarting alone even if you turn it off and/or force stop it
 
jabbb said:
by disabling you mean turning them off or force stopping?..I've seen apps restarting alone even if you turn it off and/or force stop it
Click to expand...

If you go to Settings > Apps > All and select one of those pre-installed apps, there should be a "Disable" button next to the "Force Stop" one (where "Uninstall" would be normally).
 
I'm guessing that the "Turn Off" button is a Samsung thing (not there on my Nexus, at least). It should accomplish the same thing though - you'll probably want to Uninstall Updates first though.
 
ok thanks codesplice you've been most helpful, one more question though, regarding 360 av. You don't find it useful that thru this app you can clean your memory, clean up disk, switch off apps from running in the background (and thus maybe saving some battery life). On my s4 mini you can clean your memory and turn off active apps from task manager but it doesn't seem to be the same thing with the 360av feature. You think these features are worth of the battery energy?
 
jabbb said:
ok thanks codesplice you've been most helpful, one more question though, regarding 360 av. You don't find it useful that thru this app you can clean your memory, clean up disk, switch off apps from running in the background (and thus maybe saving some battery life). On my s4 mini you can clean your memory and turn off active apps from task manager but it doesn't seem to be the same thing with the 360av feature. You think these features are worth of the battery energy?
Click to expand...

I'm not familiar with 360 av specifically, but in general those "clean up" operations are really unnecessary - and may actually be impeding performance/stability instead of improving it. "Clean your memory" is particularly suspect in my eyes: Android already has routines in place for managing memory, and using another app to try to do it better actually just gets in the way. The same goes for switching off (killing) apps in the background; unless something is grossly misbehaving apps are allowed to run in the background for a reason, and interfering with that reason means that the Android OS will have to work harder to do its thing.

To that end, I really recommend using the Greenify app instead. It makes it fairly easy to find specific apps that you don't want to run in the background (I use it largely for games which would otherwise spam me with notifications while I'm not playing), and automatically suspend those processes when you haven't used them in a bit. If you decide to try out Greenify, let me strongly recommend that you don't just Greenify ALL THE APPS: instead try to intelligently analyze what's going on and make choices accordingly.

And since you also mentioned cleaning up the disk: I use an app called SD Maid to periodically scan my storage for files left over by uninstalled apps, duplicate files, and other sorts of space-hogging data that can generally be safely deleted. I much prefer this hands-on on-demand approach to something that's going to run in the background all the time and try to do it for me.
 
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