Why Can't They Fix This?

[Se7enLC]

When most people are faced with a problem like this, they just have to unscientifically try a bunch of things, because they can't just go out and buy a bunch of extra phones just to test them, and they can't leave their daily driver on a table for a full day. But you've got those extra test phones, and it's not that hard to swap over to another phone for the sake of SCIENCE.

 

You tested your S9+ to the newly-purchased S9+ and saw a huge difference. Since you weren't actively using the phone at the time, that means it can't have anything to do with your usage patterns. It must be either the hardware or the software. To test this, you really need to factory reset both devices and set them up identically. If the problem persists, it's a provable hardware problem. If the problem disappears, it's a software or configuration problem. Isn't that exactly what you'd do to diagnose a PC problem? You wouldn't just keep fscking around with a borked Windows installation, you'd reimage the machine.

 

If you determine that it is a software issue, then you can start adding applications back in until you find the culprit. Most likely you won't find it, and when you get the new installation back to fully installed, it will work just fine.

[Zincfusion]

I'm a S9+ user and had some battery drain issues previously too, here's how I fixed it.

 

1) Go to Device Maintenance in Settings and click Optimise Now, this does a pretty good job clearing out trash in the phone without losing settings or personal data

2) Upon completion, go back into Device Maintenance and click Battery

3) Scroll to the bottom and click Unmonitored Apps

4) Make sure no apps are in this list. Don't worry, notifications still comes in, I've tested them. The problem I've noticed are some apps automatically installed themselves in this list and basically the OS does not monitor or regulate their usage hence they will keep running even when you killed them. Apps in this list are provided with unlimited power usage at all times.

5) Once the list is cleared, go back and click Always Sleeping Apps

6) Add apps that you don't used often to this list, I usually add apps that I used at most once a day or less

 

To find the rogue app (still trial and error though)

1) Go back to the Battery page

2) Click Save Power, this kills all running apps including their background tasks. Notifications will not come in unless you run the app again!

3) Use phone normally and check back at this page every few hours, if you noticed abnormally high drain, the culprit is likely in this list

4) Repeat this process with a smaller number of apps to narrow down that culprit app

 

I've helped a few friends fixed their S9+ battery drain with the above steps, hope this helps

Also, I'm using Battery Mix to monitor battery usage as the built in monitor wipes off the history on every charge, Battery Mix allows me to see my usage trend over long periods so that I can spot abnormalities.

 

[blaze756]

Do you set up new phones from backup or as new phone, this could contribute to your battery life problems?

[Speed Weed]

I get below 3 hours SOT with the S7. I am a light to moderate usage. 

[Moderateinsanity]

I have owned the Galaxy S4, Note 4 and S7 and have had the same issues where while idling it will get so hot that I can't hold it or leave it in my pocket and the battery life was woefully inadequate. My S7 for instance, with minimal usage, would rarely make it through an 8 hour work day.

I now have a Xiomi Mi Mix 2 with lineage OS and have had many nights where I would forget to plug it in and still have plenty of battery for the next day.

[Egg-Roll]

@LinusTech Smash the phone (or something) make it go viral about how bad their phones are 

 

Simply because it is Samsung, always has been... Family members S3 always being repaired, My S4 overheated constantly, The note 7... Someone I know had their S7 (I think) battery expand, they are not a heavy user.

 

If you want them to notice you do something shocking towards their bad device or state you will not only never review their products but state they are untrustworthy and unreliable as a company when issues arise.

[Ishant]

Hi Linus,

i have the same exact problem with my galaxy note 8 where it would give me a screen on time of 2 and half hours even when i am not using it. the battery just drains. i noticed that when the battery just drained one night from 80 percent to just  to 0 for no reason. since then;   it has that issue of battery going from 5 and half to 2 and half. i have tried contacting samsung about it but as i bought it from USA and i stay in Malawi, Africa. thats why i cannot give it for replacement. i am really frustrated and i hope you could help.

@LinusTech

[Milyan360]

Quote

I think linus should download this app onto his S9 and the new S9 and it should be able to tell you how many cycles the battery has gone through and what the health of the battery is. This app just reads one of the files on the phone thats used to tell the health of the battey so its a pretty accurate reading. Battey capacity calculator apps also come very close to this number so its safe to trust it.

I currently use an S9 and I always end up with a half dead phone that feels like it was taken out of an oven after I take a nap

@LinusTech

 

[WR10]

Not sure if it's just a Samsung problem as I have battery issues with my LG V30+ as well, however, mine occurs randomly, not everyday. I'd say the drain occurs about 4 out of 7 days per week, and like Linus said in the video, the battery while using the phone is actually fine, however once it goes on idle, it can easily use up an extra 5-10% per hour for me. I'm not a heavy user AT ALL, most of my days my screen on time is about 1 hour within a 10 hour time frame and my battery drops to 40-50% (when the drain doesn't occur a 1 hour+ SOT can last me 24 hours before it reaches the 50% mark). 

 

Checking with the phone's settings, the drain is caused by mdnsd, and 'system' will take up half my battery usage with mdnsd using most of the battery. I've done some googling and what I found out is that firefox and some drone app causes the mdnsd to activate, however I don't have both of those apps. Naturally, I figured that some app is causing the mdnsd to activate so i tried force stopping them one by one to see if any of them causes mdnsd but none of them show signs of activating it. This is very frustrating.

[Egg-Roll]

14 minutes ago, WR10 said:

Checking with the phone's settings, the drain is caused by mdnsd, and 'system' will take up half my battery usage with mdnsd using most of the battery. I've done some googling and what I found out is that firefox and some drone app causes the mdnsd to activate, however I don't have both of those apps. Naturally, I figured that some app is causing the mdnsd to activate so i tried force stopping them one by one to see if any of them causes mdnsd but none of them show signs of activating it. This is very frustrating.

My guess is background apps like facebook etc. Also if you notice apps being continuously updated disable google play auto update on wifi as well.

https://forums.att.com/t5/Android/What-is-mdnsd-and-why-is-it-killing-my-battery/td-p/5015034

[Muhvinssi]

I'm having the same problem with my honor 8 lite

[HtotheG]

I have a galaxy s8+ and I have been experiencing the same problem. My phone battery goes like crazy and it doesn't seem to even be affected by screen on time which is ridiculous. I have been trying so many things but also have not gotten any closer if anything you find helps I would love to know thank you for making me feel like this is not just my problem for something stupid I did. 

[TheEye]

I work for a mobile game developer and have noticed that if you use the device while its charging it degrades battery life. So if your using it like that that's your problem.

[MrDodojo]

Response to 

The S9+ being hot is a corrupt kernel or no/bad battery config/software calibration, likely some issue because of flashing with haste(Argh Samsung)... 

reflash everything with odin.(without rooting of tripping knox)

[werl]

Here is a bit of an odd one, but my friend has similar issues because of sweating, damaging the device one way or another.

[Joescalon]

It has to be something to do with the screen off time. I will use my Note 9 while working for some light streaming, social media, and GPS navigation and be at 10% after 12 hours, with 2.5 hours SOT. Or I can stream twitch all day on my day off with 9.5 hours SOT and be at 10% battery life. My last phone iPhone X was nearly opposite but had roughly same battery life...terrible.

[Poor Luck Pierre]

I've had similar problems over the course of 3 generations of Notes. Problem usually ended up a lot worse if I traveled or if I had bad connection to either a wifi network or more significantly my mobile network. Both bad internet and phone reception could cause my battery to free fall at times as if it was in full use. Turning the phone off and back on at times would show different battery values (Either lower or higher). Battery replacement usually didn't solve the issue. Felt to me like it was either related to the phone trying to constantly connect to a network or an app constantly trying to force a connection. 

In essence the phone never went to sleep mode. 

[kerb28]

i had same problem on my pixel 2 with wear os could not see any think under battery meter because it a show up under google play service but when i was trying to find what was eating up all my data every month found it out it was wear os eat 20gb of data after unstalling i gone from 20%battery at end of day back to 50% battery.

[Jelle4Life]

Hi linus,

 

The "always on screen" turns itself off when in your pocket. It uses the proximity sensor to do this. If there is a problem with your proximity sensor then it may turn off randomly. Or not at all...

 

Mine is faulty... Just figured it out

 

Kind regards.

Jelle.

[dogwitch]

sounds right. had same issue with a s4 2 times.

[psd]

Very long shot but since you mention its only on samsung devices and its mainly specific to 1 person. 

 

You might can say that also 1 thing they might have in commen is your sim. It might be worth to check if your sim is slightly bigger then normal or creates a small kinda short wich might kill the battery over time and makes battery warm. Since you might assume that samsung keeps using the same simholder methode every device change for the last few year since why redesing something if its ok.

 

Annyway doubt it is but just a gues outside the normal realm of software blaming

[Xio88]

You switch out your sim-card alot right?

 

Maybe your sim-card broke, and is throwing interrupts causing the CPU to stop idling.

 

[Naman1265]

I've the same issue that you have, and I've checked everything and everything was fine. I even tried to replace my battery twice, but nothing works. So if anyone has any idea what's going on pls tell 

[MrDodojo]

8 minutes ago, Naman1265 said:

I've the same issue that you have, and I've checked everything and everything was fine. I even tried to replace my battery twice, but nothing works. So if anyone has any idea what's going on pls tell 

Reflash everything with odin..

[Buyingbf_]

1 hour ago, MrDodojo said:

Response to 

The S9+ being hot is a corrupt kernel or no/bad battery config, likely some issue because of flashing with haste(Argh Samsung)... 

reflash everything with odin.(without rooting of tripping knox)

I have a hardware monitoring app on my S8 that loves reporting Unaccounted battery loss in the history. Would the bad battery problem be the issue here?