yashsingh1/xdaforums huggingface dataset:
[T-Mobile Samsung Galaxy S6] sodaboy581:
Can confirm Wi-Fi calling preferences solve cell standby battery drain completely for those with poor cellular signal at home. I just discovered this myself and came to post here, but searched first to see if someone else discovered it before me. :)

The place I live in has terrible T-mobile coverage inside of the building. This results in a massive battery drain while on standby, even with Wi-Fi calling on.

What I'd end up doing every time I'd get home is turn on Airplane Mode and then turn on Wi-Fi to help alleviate the battery drain. When I'd leave the house, I'd then turn off Airplane mode.

Yesterday, though, I went into the Wi-Fi calling options and set the "Never Use Cellular Network" option to on. I discovered it is a MUCH better solution than toggling Airplane and Wi-Fi mode when at home. Setting the Wi-Fi calling option to "Never Use Cellular Network" hardly uses the battery at all. My phone has been off the charger almost 2 hours and it's still 100% battery and it's still able to function with Wi-Fi and Wi-Fi calling for just about everything. I'd suppose the only thing you'd lose is cellular GPS, but don't really need that indoors.

Yes, I have to remember to turn off Wi-Fi calling when I leave the house (or I don't get cell service outside the house) and turn it back on when I come back home, but that's really not an issue as I use one of the customized quick buttons to do that now in one button instead of previously where I had to tap two.

Love it. :)
[T-Mobile Samsung Galaxy S6] ambervals6:
No idea what battery problem is OP talking about. Most probably some app running in the background.

Sent from my SM-G920T
[T-Mobile Samsung Galaxy S6] Alarand:
I think it has something to do with phone radio. It seems to have the same usage for me as radio-interface.

Forgetting my network then turning wifi and location off then clearing cache and reenabling actually helped my phone radio usage by a lot. There seems to be an issue with some aspect of the data connection where it encounters an error and just loops trying to rescan / reconnect.

Same here, kernel and android-system seem to be using higher than normal battery. Tried several different kernels
[T-Mobile Samsung Galaxy S6] popokrew:
At this point I'm just going to do a fresh install when 5.1.1 is available with root. Hopefully they fixed it.
[T-Mobile Samsung Galaxy S6] dchamero:
I think is pretty clear where is the problem. If you enable WiFi Calling in any other phone, as soon as it is enabled, the radio for mobile is turned off (no lines), but on the S6, it keeps being on (and most likely it keeps being engaged as if you were in a call all the time). It would be really easy to fix, but it looks like none of the programmers from Samsung (of from Tmobile) read this forums.... :(
[T-Mobile Samsung Galaxy S6] Dr. Fed:
If it were only that simple. Have you ever tried switching Wifi Calling preferences to "Never use cell"? Now the phone stops using the cell radio. But in this state, if you now shut off Wifi (for example if you leave the house), the cell radio is frozen on "off" and there is no data or voice signal. In order to correct this, wifi has to be turned on again and then wifi calling has to be switched back to "Wifi preferred." Now wifi can be shut off and the cell signals kick in.

So overall, the firmware has some major bugs that the update has not addressed. Battery killing firmware bugs.

---------- Post added at 02:00 PM ---------- Previous post was at 01:58 PM ----------

Shut Wifi-calling off before shutting off Wifi and the cell radio does not freeze.
[T-Mobile Samsung Galaxy S6] dchamero:
Yes, if you change it to Never use cell it works as it should BUT you have to remember to change it back every time you leave the wifi, because if not you have NO data ever.... very annoying and not practical. I personally switched OFF Wifi calling all the time and I don't have the problem anymore, but they should definitely fix it because many people need it
[T-Mobile Samsung Galaxy S6] ac21365:
I hear that.

"Cell Standby" is still using more power than it should, and my battery life has tanked with the 5.1.1 update. The 'fixes' from 5.0 don't work (VoLTE off/WiFi Calling off) with 5.1.1. What -was- a 5-5.5hr screen on time phone before the update now gets 3.5-4hr post-update, configured as close to it was before. I called T-Mobile and spoke with tech support to give them this information. Crap battery life post-update isn't an uncommon issue, according to the tech.

That's what I get for taking the update and not listening to my inner nerd.
[T-Mobile Samsung Galaxy S6] Dr. Fed:
The fix (disable VoLTE and WiFi Calling) still works for me. I factory reset after taking the update, maybe that's why it still works? Did you try that?
[T-Mobile Samsung Galaxy S6] ac21365:
Factory reset was the first thing I did after the OTA. Tried that as well as Reset/clear cache through the bootloader since. It's gotten better, but not back to where it was before 5.1.1.
[T-Mobile Samsung Galaxy S6] Dr. Fed:
Cell standby drain still happens with WiFi Calling on "never use cell network" as long as VoLTE is on.

I keep trying different combinations... cell standby drain continues to occur in situations that make no sense.
[T-Mobile Samsung Galaxy S6] bubblebuddyi:
For what's its worth, I had the horrible cell standby issue after the 5.1 update, and after s few days it just disappeared. Can't tell you why, but it did.
[T-Mobile Samsung Galaxy S6] masri1987:
I'm still on 5.0.1 and i have wifi calling on "if i have no cell signal" and i am not seeing the issues you guys are getting, 100% to 0 on medium to heavy usage 2 hrs of bluetooth streaming 1 hr of phone call i got 4 hrs of SOT.

I'm using greenify as well.
[T-Mobile Samsung Galaxy S6] lonewolf5460:
Just to let you guys know 5.1.1 fixed this for me I get 2 days 7 hours off the charger with 3 hours 40 minutes of screen on time. No more crazy drain location is on and bluetooth was on 70% of that charge too.
[T-Mobile Samsung Galaxy S6] masri1987:
With heavy usage
[T-Mobile Samsung Galaxy S6] ac21365:
Now that it's about a week, I'll admit that 5.1.1 has gotten significantly better with time. Why did what seemed like a firmware issue get progressively better with time? Who knows.

My battery life isn't -quite- where it was, but it's close... close enough for me to not be quite as upset as I was right after the update.

We'll see if it continues to get better over time. I might even give VoLTE a try again once things settle out. We'll see...
[T-Mobile Samsung Galaxy S6] masri1987:
so i have been running the phone without using Wifi calling since full charge, and my awake time and screen time are much more identical than my prior runs...

perhaps it is an issue like you guys are saying.

Gonna go with a international rom to see if battery life is any better
[T-Mobile Samsung Galaxy S6] phositadc:
How did you get center clock in status bar?

Sent from my SM-G920I
[T-Mobile Samsung Galaxy S6] tbns:
Da fuq? I don't get that with a debloated, greenified, modified kernel, custom-ROMed S6! What are you doing with your S6? Keeping it in cold storage?
[T-Mobile Samsung Galaxy S6] masri1987:
I have no idea, it might be the urbane theme and then the blacked out theme? Not quite sure, also tapping the clock turns off screen.

I also have greenified stock kernel, on looper 2.0, and i froze a bunch of stuff.

My phone deep sleeps like no one's business. i've gotten as low as 1% drained overnight so far.

I also use leandroid
[T-Mobile Samsung Galaxy S6] XTRoRDiNAiRE:
Man the battery life is horrible on this phone
[T-Mobile Samsung Galaxy S6] Dr. Fed:
well done. too bad that can't be achieved with stock unrooted. I am trying, however, but I'll never come close. The "battery power optimization" settings where you can manage your apps seems to help. But i have to keep VoLTE and WifiCalling off eliminate cell standby drain.
[T-Mobile Samsung Galaxy S6] masri1987:
Why are you not rooted sir?

Also, I'm trying to truly determine if Wifi calling is an issue... Is it an issue if you have Volte off and wifi calling on?

I don't understand how T-Mobile could just allow this bug be present in release software, very horrible.

For the record i've had VoLTE off since my Note 4, so i was just programmed to always turn it off since i never noticed a quality diff in voice calls.
[T-Mobile Samsung Galaxy S6] Dr. Fed:
Why am I not rooted? Just a personal choice. I knew when I got the phone that Samsung Pay was something I'd want to try out in the future. I also knew that AOSP roms wouldn't be available for a long time (maybe forever). I thought about maybe using Ping Pong (in Ding Dang) and then Flashfire, but I became curious about the 5.1.1 update, specifically if it would improve RAM management and eliminate the cell-standby bug. Knowing full well that root would be broken for the foreseeable future, I took the OTA. I'm trying to see how good I can make this full stock experience.

Regarding the cell standby drain, the only success I've had is with VoLTE and Wifi Calling off. I thought I had success with VoLTE off and WifiCalling set to "never use cell network", but now I'm not so sure. I do see a difference in call quality with VoLTE off (I get less dropped calls when it is on).
[T-Mobile Samsung Galaxy S6] masri1987:
Got it....

I am gonna test it with wifi calling on volte off,

already at 99% and i see my phone is awake 50% more than SOT.
[T-Mobile Samsung Galaxy S6] blv7:
Crazy Standby Battery Drain!!!

So Today, I had my phone on 100% charge at around 2 o'clock-ish. At the time of this post, it is 11 o'clock and i have f***ing 13% left without using it at all!!!!

*Note: I Have the Light Flow App installed and it recieved an update yesterday to resolve the issues it had with the 5.1.1 update where the notifications would just blink the blue color no matter what color you chose. And I had also installed Kik (deleted it a few hours ago).

Here are my battery stats since idk how to post a screenshot :/

Messenger (Facebook): 7%

Android OS: 6%

Facebook: 6%

Instagram: 5%

Google Play Services: 3%

Cell Standby: 3%

Amazon: 2%

Screen: 2%
[T-Mobile Samsung Galaxy S6] NYLUVBUG:
I shared similar thoughts. But now having this phone for a month. I'm ready to root and throw a rom on it.
[T-Mobile Samsung Galaxy S6] encrypshun:
This update did well for me. Much better results on battery. I've seen as high as losing 1% every hour overnight, and that is with VoLTE and WiFi calling enabled. I just disabled backing up to Google, turned off location services until I need it, and even disabled some wifi features. Very happy with the device, which is why I too won't root and ROM it.
[T-Mobile Samsung Galaxy S6] hegdesaspect:
The "battery power optimization" has been removed in the latest update that was rolled out after 5.1.1. That is very bad. Samsung does not allow rooting also with 5.1.1 as the kernel is modified to protect rooting by default. With rooting I could use Greenify (Paid). Samsung should either allow rooting or give the "battery power optimization" feature back.

There are some workarounds to root S6 with 5.1.1 by patching a different kernel. I got into some issues with that. Phone hangs sometimes, reboots unexpectedly, etc.
[T-Mobile Samsung Galaxy S6] Dr. Fed:
I still have the "battery power optimization" thing after the latest update.
[T-Mobile Samsung Galaxy S6] hegdesaspect:
That is interesting. Can you please mention the Kernel Version? Mine is as follows:

3.10.61-5499188

Tue Jul 28 20:01 KST 2015

I got an OTA update of around 250+ MB and this is after the major 5.1.1 update. After this minor update, the battery power optimization feature is not available.
[T-Mobile Samsung Galaxy S6] Dr. Fed:
T Mobile S6 Build COF8. Do you have the T Mobile S6?
[T-Mobile Samsung Galaxy S6] hegdesaspect:
No. I do not have T-Mobile. Mine is SM-G925I. I have now sent an e-Mail to Samsung Support to clarify about the behavior. I will update here further on that.
[T-Mobile Samsung Galaxy S6] hegdesaspect:
I got in touch with Samsung Support over phone. As per them, the feature will re-appear in the next update. They did not give me any specific reason for this change. I would assume there must have been some issues with it.

So I am now waiting for the next update from Samsung. I really wish they re-introduce the feature. Or else I will have to go with twrp+patched_kernel+greenify. Or the other workaround is to ODIN downgrade to the first 5.1.1 patch.

This new minor update introduced something called "Auto Restart". The option description says "Keep the device running smoothly. Automatically optimize and silently restart your device at set times". I am not sure what all optimization it does. Not sure if it does anything related to the battery consumption. Whatever it is, I think this new option description is in a way suggests that to run the device smoothly, one needs to restart it frequently! In contrast, the last time I restarted my iPad was around 3 months back!

However, I am ready to do this Auto Restart too if it really improves battery consumption. Testing it now...
[T-Mobile Samsung Galaxy S6] Dr. Fed:
Interesting. And what device forum is this?

You may want to post in your specific device's forum, I think you'll get better info there.
[T-Mobile Samsung Galaxy S6] hegdesaspect:
Oh! I did not notice that at all. Sorry for that. I saw only the title and thought it is about Galaxy S6 Edge in general. Thanks for pointing that out and I shall post it in the right forum. Sorry again for the noise.
[T-Mobile Samsung Galaxy S6] Dr. Fed:
No worries mate, good luck.
[T-Mobile Samsung Galaxy S6] dnknitro:
I have VoLTE and Wifi calling off and the battery life is OK. However whenever I turn on Wifi - the battery drain becomes really bad. Does anybody else experience this issue?
[T-Mobile Samsung Galaxy S6] Dr. Fed:
Yeah, everyone on T Mobile with an S6.
[T-Mobile Samsung Galaxy S6] El Jefe Cangri:
I have disabled a bunch of app that don't use, and I have them autostopped from Smart Manager and I am able to get idle percentage under 1% with WiFi and voice LTE on.
[T-Mobile Samsung Galaxy S6] Divine_Madcat:
The key is turning them off (Vo and WifiC), and then clearing the cache (i clear via TWRP, but either way). After doing so, without disabling anything else (and even leaving WiFi on) i am at less than 1% deep sleep drain.

Though, it may also be running Rapture 2.1 w/unikernel-v6 that is helping too.... But i know i saw an improvement on clearing cache.
[T-Mobile Samsung Galaxy S6] KCRic:
I was always under the impression that the phone app is what's active when there's an issue where the phone acts like its constantly on a call. Cell standby is for tower scanning/hopping and also background WiFi scanning (when its set to scan when when its turned off).

Based on that I would guess the issue here is with either the modem/radio or the towers. I'm sure a lot of us have noticed a decline in speeds and/or reception over the past few months or even year. If the phone is working longer or harder to transmit data or find a good tower then we would naturally see this exact issue. Just my 2 cents. I think were barking up the wrong tree.

Sent by the white rabbit
[T-Mobile Samsung Galaxy S6] rha_december:
Hi guys, so I kept my T-Mobile S6 off the charger throughout the day and this is what I'm getting. Could it do better, or is this fairly normal? I'm on 5.0.2 and rooted with ping pong.
[T-Mobile Samsung Galaxy S6] Dr. Fed:
way better than what i get, on stock unrooted 5.1.1
[T-Mobile Samsung Galaxy S6] vinnyjr:
After turning off VOLTE my battery problem still existed, had to reboot the phone and seemed to fix it. Turned my email sync off to manual and overnight only loosing 2%. That ain't bad. Don't use WiFi very much at all, have very strong LTE signal, I get entire day out of my battery. Instagram is a big battery hog, if I use it, I log out when finished. I think it's lollipop that is the battery killer, all phones running lollipop have some sort of battery issues. My stock Note 4 has lost battery life after update. Just my opinion.
[T-Mobile Samsung Galaxy S6] maxjivi05:
This is pretty good, lots of items frozen via Titanium but pretty good battery life now. Sad we have to resort to root just to have decent battery life!
[T-Mobile Samsung Galaxy S6] dnknitro:
Well, you can freeze (technically just disable) any app without root using Debloater (a windows application).

Worked for me without any issues and now I am happy S6 owner with really good battery life :)
[T-Mobile Samsung Galaxy S6] zathus:
GPS on, Bluetooth on, WiFi on, WiFi calling off, volte off. 5.1.1 not rooted.

4% over 9 hours.
[T-Mobile Samsung Galaxy S6] Dr. Fed:
So what's the recipe for this success?
[T-Mobile Samsung Galaxy S6] zathus:
What I listed was pretty much it. I have no special apps running or anything like that. I did use the settings in battery to turn off a bunch of apps from running in the background. But those are not system apps anyway so I don't know if it does anything. My disable list is pretty standard too. Just all the extra bloat that's not Google or Samsung I disabled. I also keep location history off in Google settings and don't have Google now enabled. I still have the okay Google function but no cards
[T-Mobile Samsung Galaxy S6] aff219:
Id like to chime in here a bit with something that is really bothering me about this phone.

I've had my S6 since release (And had to return it around 6 times due to various defects initially, so I've seen the battery life on multiple different models).

My friend just got his s6 last week (att provider), i helped him disable processes in spp manager and that's it. Today by lunch he had 15% more battery than me, around 6pm he was at 50%, I was at 20%.

He connects to wifi and links his bluetooth headset to listen to youtube/music with screen on for a large portion of the day....i tend to surf web.

I'm currently running 5.1.1 COH8 stock unrooted, Ive done as much as i can to optimize battery life on my own phone including:

-Tasker profiles to disable wifi when not in use for various occasions

-debloater to shut down as many bloatware processes as possible

-disable/uninstall as much garbage as i can

-black backgrounds

-disable wifi calling

-disable voice over LTE

-greenify everything i can

-use android assistant to monitor and disable crap during use

-turn off location services / keep bluetooth and sync off less actually needing to use them

With all this done, I get around 5 Hours of screen-on time (today was first day of testing since using debloater and tasker), and still come out 20% under him by 5pm.

Ive not rooted/installed custom roms yet because i havent found a way to do so without tripping knox for COH8, but thats about the last step i can think of to conserve any more juice.

Long story short he seems to have significantly better battery life than me regardless of heavier use on his side and maximum optimization on mine. What gives?

Picture attatched is screenshots of our phone info, as you can see hes running an older version, but even when I was running on older updates I wasn't seeing anything like his battery life.

We're both curious how much battery life he'd get if I were to optimize his phone like I did mine, given how well his is handling it currently with minimal optimization
[T-Mobile Samsung Galaxy S6] Dr. Fed:
I can concur with this. My "wife" has the S6 on Verizon, her battery life is much better than mine. Both phones unrooted, fully stock with no optimizations. From what I've seen, when comparing against Att and Verizon, the T Mobile S6 has the worst battery life. Not sure about Sprint. The cell standby drain seems to be the culprit. VoLTE and Wifi-calling on T Mobile's network I guess.
[T-Mobile Samsung Galaxy S6] jetbruceli:
I hate to say it but, this flagship lost most of its kudo points by arriving with such a low level battery. They didnt have to give us removable battery but at least a decent battery to get through the day. My S6 International doesnt make it no where near my wifes s5 International. She gets 4.5 screen on time versus the s6's 3.5. It's a shame and I wish they would fix something. I do believe though part of the problem is in the ram management. If an app has to reload everytime it launches then the system has to use extra resources everytime. Maybe if that is fixed we could see better results.
[T-Mobile Samsung Galaxy S6] aff219:
Small update:

Me and my friend began comparing battery stats Friday morning at 7:45am. Saturday at 1:10pm he Texted

him: "19% Battery"

me: "no charge after work?"

"not yet still not low enough to charge it"

I charged my phone by 8pm Friday as it was down below 15% and was at about 75% battery by the time I got his text Saturday (didn't use phone at all for the day at that point)

Keeping in mind as I said earlier, I'm -FAR- more optimized for battery life than him, and his using habits are more intense than mine because he uses bluetooth headset and both spotify and youtube to listen to music, and when using youtube he keeps the screen on since youtube auto-pauses if you turn it off

That's an ABSURD difference in battery life between the two carrier versions and I'm really curious as to why it's like this. Hes got to be getting 2-3x more life than me.

if the S6 in general just had this kind of battery power it wouldn't bug me that much, it would suck, but at least I know it's not a special issue for me, but knowing im as optimized as I am for battery power and my friend isn't, yet still gets so much more battery time than me just because hes with a different carrier really puts a bad taste in my mouth for both this phone and Tmobile

The only upside, is knowing other carriers have such better battery tells me HOPEFULLY this phone will receive an update soon that fixes the issue, because it should be easy to figure out what's different between the two
[T-Mobile Samsung Galaxy S6] Dr. Fed:
Well, after latest update... Battery life still sucks.
[T-Mobile Samsung Galaxy S6] aff219:
latest update has actually caused me to take a fairly significant hit (almost 50%) in battery life. Now cell standby's total connection time continues to increase even with wifi calling and VoLTE disabled so there's nothing I can do to stop it

more info here:

http://xdaforums.com/tmobile-galaxy...9-10-2015-g920tuvu2doh6-t3199238#post62794725
[T-Mobile Samsung Galaxy S6] shadowster:
I had the cell standby issue after the update till I wiped my cache and changed my wifi calling settings to off with Cellular Network preferred.
[T-Mobile Samsung Galaxy S6] Dr. Fed:
I read the T Mobile Note 5 thread regarding battery life. Seems like the cell standby drain plagues that device as well, which makes perfect sense. Some users have gotten amazing battery life however. Just like with this device, there is a huge disparity in battery life from one user to another. I'm trying to learn what the least common denominators are for those without root. We need more people with the s6 unrooted to post their formula for success.

For those of us who rely on WiFi calling, is there a solution? Is root plus custom rom the only way? Package Disabler Pro? Factory reset? WiFi calling cell preferred? GPS only for location services? VoLTE disabled? Is there any way to use WiFi calling and VoLTE and still get great battery life? Do we have a concise winning formula yet?
[T-Mobile Samsung Galaxy S6] fix-this!:
The new ota sucks hard. Terrible battery life.