yashsingh1/xdaforums huggingface dataset:
[AT&T Samsung Galaxy S II SGH-I777] tboooe:
From what I read, the issue with the battery life is caused by the stock kernel so I am not sure how flashing a rooted, stock kernel will help. As a matter of fact, I did just root my phone and the battery issue remains. I just read that this modified kernel addresses the problem:

http://xdaforums.com/showthread.php?t=1263838

The only drawback is that it doesnt support modified ROMS like Cognition, etc. I am not sure if any of the modified ROMS addresses this issue though.
[AT&T Samsung Galaxy S II SGH-I777] dandrumheller:
menu>settings>privacy>factory data reset

I did NOT wipe my USB storage (not that I have a lot of stuff on there yet)
[AT&T Samsung Galaxy S II SGH-I777] Entropy512:
SiyahKernel's source is not available (the developer is not complying with the GPL) and it is not compatible with the I777.

I think he got lucky with fixing the AOS bug, and I'm not sure if he even fixed it. Based on reading his thread, his development methodology is "throw **** at the wall to see what works". Probably that's why he hides his intermediary work.

I am now positive that at least some instances of high Android OS battery usage are false readings - I'm running a kernel patched up to 2.6.35.14 and Android OS percentage is WAY down, but my drain rate and deep sleep percentages haven't changed a bit. (They were great even when AOS was at 60%.) All this past week I'd get less than 1% an hour drain when the phone was idle overnight and AOS would still be at 60%. In fact, the HIGHER it was the better my battery life was - more evidence that in some cases, it's a reporting bug.
[AT&T Samsung Galaxy S II SGH-I777] manbeer:
Words with friends chewed though my battery like a monster. I'm talking like 50% in under 2 hours. Went from full to dead in only 3:15 display on time and 8 hrs and it was hot as he'll even uc to 1.0 and undervolted. be forewarned about this app on this phone
[AT&T Samsung Galaxy S II SGH-I777] phonic:
Yup, I mentioned this earlier. It's crazy. When playing, the battery level reads like a minute countdown. Due to delays in playing a word, the other player to receive it, them choosing their own word, and me receiving theirs, it basically takes 3-4% per round. I used my phone all day today, from 10AM on. Played Angry Birds for an hour, streamed music, made some calls, downloaded apps, read the news, etc., and after 10 hours I had ~40% left. After playing Words with Friends for 25 minutes, I was down to 24%.
[AT&T Samsung Galaxy S II SGH-I777] apexi350z:
I have two AT&T verson's GSII, and one is rooted, and other is not. The one that is NOT rooted has GREAT battery, while the rooted one does not. I have tried the Congition X2 rom, swap physical battery between two phones, but the results are still the same.. so today I flashed back to the stock kernal, rooted and the battery was still draining too fast.. I believe the reason was because it didn't go to "deep sleep" long enough.. So I did a reset from factory recovery (hold vol-down+power), and it finally fixed the problem! not sure what was running that caused it, but it finally has great battery life!

Just want to share my experiences with you guys..
[AT&T Samsung Galaxy S II SGH-I777] kinubic:
did a factory reset and rooted ~ AOS hovers around 10-13% now comapred to before around 84% lol
[AT&T Samsung Galaxy S II SGH-I777] dfxda:
I'm new to this but what the hell, I got a GS2, the day it came out, and well, I can get 3-4 hours maybe of internet time on it before the battery is drained, and then when I have to charge it, it takes forever. Is this normal?

I gotta say though, this phone rocks, needs a few things fixed on it though, but great phone. but the battery........
[AT&T Samsung Galaxy S II SGH-I777] Entropy512:
When you mean "internet time" - do you mean 3-4 hours with the screen on?

That's mostly normal, maybe a bit low - drop your brightness settings.
[AT&T Samsung Galaxy S II SGH-I777] gqonmars:
Update, rooted uninstall those apps, now I get 25 hours with 13% left, having 3hours of screen time.

Android os 41%

display 23%

Android system 12%

Cell stand by. 5%

Sounds like a master reset then reroot will do better, but, I am fine with these numbers coming from 12 hours to 3%.........
[AT&T Samsung Galaxy S II SGH-I777] dandrumheller:
This sounds pretty close to what I got on that first run after reset - a good portion (probably 70%) of that on time for me was spent at home with wifi on for data, and a solid cellular connection via MicroCell.
[AT&T Samsung Galaxy S II SGH-I777] Simba501:
This is what I get. The amount of hours mine lasts solely depends on how fast I get to just over 3 hours of screen time.
[AT&T Samsung Galaxy S II SGH-I777] gqonmars:
My friend have the sgs2 for sprint, goes 2 days easy with stock every thing. I am guessing bigger battery, less Bloatware and better connection than me with AT&T. Here in NYC area. :mad::confused:
[AT&T Samsung Galaxy S II SGH-I777] jetarpon:
Can anybody explain what happened here? I was having problems with my bluetooth, so I rebooted my phone. When it came back, my battery level had dropped about 20%.
[AT&T Samsung Galaxy S II SGH-I777] dandrumheller:
I've seen batteries do those on occasion. Not really sure what causes it. Holy wakelocks though. ..what do you have running that is keeping your device awake so much?
[AT&T Samsung Galaxy S II SGH-I777] MikeyMike01:
Someone took a bite out of your slide.
[AT&T Samsung Galaxy S II SGH-I777] knimrod:
So far, I'm missing my iPhone 3GS.. The I777 is my first android phone (actually my 2nd.. I had an Atrix for ~3 weeks and swapped it for the GS2) and the short battery life is killing me. I can only get about 10-11 hours before having to recharge and that's with me being paranoid and stingy with usage. I could go 2 days on my 3GS without worry (The Atrix was also way better than the GS2). I've done most of the usual things for increasing battery life with only a slight improvement. I still routinely see the phone is awake at times with the screen off in the battery history and I suspect that the bloatware is the issue.

Is there a guide to exactly what battery robbing apps/services can be safely removed on rooted I777 and the best way to remove them?

Thanx.
[AT&T Samsung Galaxy S II SGH-I777] apexi350z:
have you tried juicedefender? It gave me about 30-40% more battery life when I set it correctly.

I stream sirius xm for about 1.5-2hrs daily, phone calls about 30-40min, 10-20 text msg, not much browsing.. my battery has 45% left after 15hrs on battery (7am-10pm)

but if you want the best battery life, then iphone still better than gsII, without much tweaking.
[AT&T Samsung Galaxy S II SGH-I777] knimrod:
I'm using "Android Booster" which seemed to work wonders on the Atrix while I had it..
[AT&T Samsung Galaxy S II SGH-I777] vladm7:
I wonder how much installing of Cognition ROM improves the situation with battery? Can anyone who did that comment with some numbers?
[AT&T Samsung Galaxy S II SGH-I777] jetarpon:
Took a walk in the morning with cardiotrainer running. Ran errands with my book playing on audible. Have tasker running, too. I have been running latitude, but I turned it off at some point yesterday. Don't remember exactly when.

I'll try to see if things are better today without latitude.

I usually plug in when I'm in the car, but I've been keeping it unplugged to get a better handle on my actual battery life.
[AT&T Samsung Galaxy S II SGH-I777] mgam888:
i777 is a lot better than the 3GS in terms of battery life at least in my experience. I was a 3GS user too and could only reach about 24 hours.

What I did:

- purchased i777 from AT&T. My world almost "collapsed" when I found out battery life is 13 hours (and I have stock applications).

- took the matters in my own hands (completely bypassed AT&T Support) by rooting the i777 and flashing to the STOCK kernel ((I followed the FIX in the 1st page)

- purchased Titanium Pro and froze the ff: apps:

*Media Hub 130

*Social Hub (2 svcs)

*SNS 1.5

*all SNS instances (FB, Tweeter, etc)

*ATT Navigation

Holy MACKEREL! i777 can easily hit 24 hours with about 25% (yellow) left. I use Exchange Sync Push for corporate email, Yahoo email, have a couple of news apps, played iheartradio for 2 hours (battery went down from 70% to 60%). I leave wifi on outside of home, but turn off gps and bluetooth.

I have also observed i777 to lose power from 100% to 90% from 10pm to 6am (overnight) doing nothing.

Charging from 25% to 100% takes about 2.5 hours (much faster compared prior to rooting).
[AT&T Samsung Galaxy S II SGH-I777] roadrash7:
I have been using cognition beta 2 for a while now and the battery life has been great I can get a whole day heavy use with 5 hour screen time. I really think that it just comes down to certain apps installed that are the battery drainers. I plan on trying beta 4 soon as I think it has a different kernel To see the difference
[AT&T Samsung Galaxy S II SGH-I777] dandrumheller:
+1. I am now getting 36 hours of uptime with almost 4 hours screen on from full to empty. I am not rooted (yet) and thus have all the AT&T bloat still on there. I saw somewhere that qik is a potential culprit, so I have not opened it since I factory reset. I just keep a close eye on what is causing wakelocks, and monitoring deep sleep time. with minimal usage I am seeing about 85% deep sleep, using CPUSpy.
[AT&T Samsung Galaxy S II SGH-I777] roadrash7:
Use Google talk and tango for video chat I think all others are battery drainers imo
[AT&T Samsung Galaxy S II SGH-I777] Entropy512:
mgam888 had a pretty good summary there.

First SisoDrmProvider is a notorious battery hog and only useful if you're playing DRMed media in Media Hub. The problem is that it wakes up EVERY FEW SECONDS to "phone home" even if you don't have a single DRMed file on your device.

Second is the SNS services. Nuking these removes some of the social network integration features, but not much. The Facebook app alone does well for me. (The Facebook app used to be a notorious battery hog but it's gotten much better lately.)
[AT&T Samsung Galaxy S II SGH-I777] Stixho:
After 50 hours my S2 battery was at 30%. I was able to accomplish this by having all data syncing off, and I took the extreme step of turn off my data packet. By experimenting with the data packet off it allowed me to get the extended battery life, because as from what I can tell I crippled all those stupid stock apps that runs around in the background wasting battery doing nothing!!! LOL

Ok so after experimenting farther I noticed that similar to everyone else whose not rooted yet, that crappy AT&T Crapware is the main cause, which is why I cripple my phone by disabling the data packet considering that I hardly use it like that (even knowing its one of the best smartphones). But below you will find a pic of my current battery usage using the cripple effect. I got 65 Hours off one charge!!!
[AT&T Samsung Galaxy S II SGH-I777] dandrumheller:
Nice battery life! Somebody correct me if I'm wrong here though - with packet data disabled in the settings, data over a cellular connection is completely disabled, correct?
[AT&T Samsung Galaxy S II SGH-I777] knimrod:
Geez... Isn't there just some way to turn off data syncing when the phone is asleep? ie. A completely manual data sync process? I can turn off data syncing now but it doesn't turn back on when I wake the phone up..
[AT&T Samsung Galaxy S II SGH-I777] Simba501:
I think Juice Defender does this.
[AT&T Samsung Galaxy S II SGH-I777] roadrash7:
I have been very pleased with battery life with this phone. I did do some things though. Flashed cognition beta 2 yet to try 4 cause I have been so pleased, removed some apps and froze some stuff too. I will never turn of backround data or sync that for me defeats the purpose of my "smart"phone but I just have my Gmail syncing. You can easily get 4 hours of screen time with this phone. I have got 5 hours sometimes.

Today it has be 14 hours I'm at 31% life left, I've had 3 hours and 15 minutes display time, over 2 hours of music playback through Bluetooth, 20 minutes of video chat. I maybe could have achieved this on my cappy but it would be near dead by now. I think I am very satisfied.

At first I had high android OS usage and it was.killing me. Like over an hour at the end of the day. Factory reset flash cog ditch qik and media hub drm and sns things and other things people have pointed out. Now android OS is only at 24 minutes. I really think it comes down to certain apps and things running. I e been watching CPU spy and I am deep sleeping like 95 percent of the time when screen is off. Talk and tango are only video chat apps that don't constantly run and suck down battery life I think. In my running services when I am not doing anything with my phone there is only like 5 or 6 things running.

So I don't think you need to kill data and sync and defeat the purpose of these great phones but there is some tweaks and uninstalling and optimizations that need to be done.
[AT&T Samsung Galaxy S II SGH-I777] tboooe:
Here is what I have done...

Like many, I was getting really bad battery usage. I would lose 4-5% every hour at idle! This morning I did a factory reset then have been adding in my apps one at a time. I then monitor the battery usage and see if the phone goes into an Active for at least one hour. I also use BetterBatteryStats and CPU Spy to ensure that my phone is going into Deep Sleep when not is use. If it looks like the app isnt doing anything out of the ordinary I add in another app and so on. So far, I am getting only 2% battery drain after 2 hours. This is with Data and Sync on. It should be noted that my phone is rooted and I used Titanium Backup to freeze some of the apps mentioned in this thread. Hopefully by tomorrow I will identify the app or apps that was causing so much battery drain.

I know this is a tedious process but so far it has been worth it as I am getting so much better battery performance. I will update again tomorrow.
[AT&T Samsung Galaxy S II SGH-I777] Stixho:
@dandrumheller: yep you're right, it does disable all data usage. But for me that's no problem because I'm always at a computer throughout the day. Once I decide to root must likely sooner than later I should be able to keep it on considering I, will be able to delete all that bloatware!!! But for new my little experiment paid off. Currently with data packet on 12hrs and already at 24%!
[AT&T Samsung Galaxy S II SGH-I777] aimfire72:
Same here, only I'm rooted and on the CogX2 rom, beta 4. Battery life was awful, draining at around 15% per hour. I'd go to sleep at night, put the phone in airplane mode, and wake up with 12% battery gone!

So I did a factory reset (still on Cog rom) and no idea what happened, but now my battery life is *awesome*! Going 9 hours so far with mod to heavy use and only down 15%! I would highly suggest this to anyone having battery problems.

And as someone else mentioned, this is a smartphone, you shouldn't need to cripple it by turning off 100 things to save some battery.
[AT&T Samsung Galaxy S II SGH-I777] Entropy512:
You don't need to cripple it by turning off 100 things, you need to un-cripple it by removing 100 crappy things AT&T added that shouldn't have been there in the first place and in most cases have significantly better free alternatives on the Market. (Most of which were removed in Cog.)
[AT&T Samsung Galaxy S II SGH-I777] gqonmars:
So far this morning...

10h 33m on battery with "86%" remaining.

android OS 55%

android system 17%

Display 15%

cell stand by 8%

phone idle 6%

Time On 22m

========================

the above was achievable after root, un-installed all bloatware and have juiceDefender running.
[AT&T Samsung Galaxy S II SGH-I777] jrl022:
Yeah there's definitely some funky ish going on with my battery life.

Bullet Points!!

- I am not a first time Android user.

- I've had the phone for 6 days.

- Stock, unrooted.

- A good few apps installed, but overall less than I had on my DroidX (and no different ones)

- Background data and Auto Sync are ON. I need my Gmail.

- I have a corporate Exchange account set to "push". It's a company paid phone. Need Email.

- Signal strength in the office hovers around -75dBm. At home it's around -100dBm.

I charted my battery usage yesterday and it wasn't pretty (More bullets!)

- Unplugged at 8 on a full charge

- 8:47am: 98% remaining. 49 mins off charger. 3 mins display time (including what it took to check)

- 10:06am: 88%. 5 minutes of total display time. I basically didn't touch my phone.

- 11:30am: 76%. 14 minutes display time. I poked at the phone for a few minutes, nothing intense.

- 12:30pm: 64%. 33 minutes display time. Couple of texts, messed with some home screens. No streaming or games.

- 1:31pm: 47%. 1h 19m display time. I downloaded and configured a couple of apps I used to have, read a couple of articles on Pulse. May have sent a text or two.

- 2:38pm: 37%. 1h 22m display time. Didn't touch the phone and lost 10%.

- 3:38pm: 29%. 1h 24m display time. Again only touched it to write this down.

- 4:31pm: 22%. 1h 29m display time. Haven't touched for fear of driving home with a paperweight.

Halfway through my drive home I got a battery alert. By the time I made it home at 5:35 it was at 9%. This is not good.

Here are the requisite screenshots:

And I did monitor the CPU usage with CPU Spy. Like some earlier users reported, most of the time is spent in that 200 mHz range. Deep sleep is only 40-45%.

SO with that said, I realize I have junk going on as far as sync and account. But I had all that same stuff going on over the last month I had my DroidX and the battery life was nowhere near this bad.

I don't think the signal strength is the biggest culprit because I'm working from home today and after 3h 22m with 15 minutes of display time I'm already down to 78% remaining.

So I suppose the next step is to factory reset the device and start trying to isolate the problem. I'll report findings here to the best of my ability.

I just wanted to put this up here for those who think there is no problem just because their particular device is getting great battery life. I'm happy for you if so, but I don't think this should be normal.
[AT&T Samsung Galaxy S II SGH-I777] tboooe:
@jrl022: something is definitely wrong. You are getting similar results as me. Do you have BetterBatteryStats? This app will tell you what is wakelocking your phone. From you charts, I can see major chunks of time when the phone is awake but the screen is not. What worked for me was a full factory reset. You may also want to root your phone and use Titanium Backup to freeze all the bloatware.

As for me, my results after factory reset and adding apps back in one at a time have been very good. I went from draining about 5% every hour to 1%. I took my phone off charger at 5:30pm yesterday and as of 4am today I had 86%. This morning I also turned off Backup in the privacy settings. According to BBS, google services was responsible for over 17mins of wakelocks, by far the biggest offender on my device. I already use Titanium Backup so I am not sure the google service is needed anymore. I will update again later today after I install a my last remaining apps.
[AT&T Samsung Galaxy S II SGH-I777] Entropy512:
Yup. Something definitely wrong. Time to go wakelock hunting.
[AT&T Samsung Galaxy S II SGH-I777] rbtconsultants:
@jrl022; After careful experimentation, I can say that Corporate exchange is easily identifiable as hitting my battery. 8-10% per hr battery drain when on "push". 5% per hr battery drain when on "every 5 minutes". 3-4% battery drain when on "every 15 minutes".

Click on Email in your battery use and see how long it keeps awake. My phone has been off battery for 4 hours and EMAIL currently says awake for 55 minutes. BetterBatteryStats shows email partial wakelocks of 55 minutes. Many/most of those little blue "awakes" in your graph when your screen is not on is Exchange Email.

So IMO, the percentages are wrong in the battery use graph, Android OS is a red herring, and EMAIL for corporate exchange is a battery hog.

Now having said that, I can live with 3-4% an hour drain with every 15 minutes refresh (vs. 1% an hour or less when no exchange email).

This is my experience.

Bob
[AT&T Samsung Galaxy S II SGH-I777] jrl022:
I think this is right on. I installed BetterBatteryStats a little while ago at tbooe's recommendation and have been monitoring it since.

My stats are almost identical to yours. I've been off charger for about 6 hours and BBS says my Corporate Email is responsible for almost 50 minutes of partial wakelocks. This is right in line with battery usage list under "Email" where it says "Stay awake....49 minutes 48 seconds". Nothing else in BBS even comes close to this kind of percentage, so this has to be it.

That's a shame, too, because I really like the way I'm able to handle my corporate email through this app. I wonder if I should consider trying another option like K9 or Touchdown? And a bigger question might be if other versions of the GSII like the Sprint or International version have this same problem with Corporate Exchange Syncing?

I'll do some research to find out I suppose. I'll also monitor drainage now that I've altered the sync schedule to see if it really is helping.
[AT&T Samsung Galaxy S II SGH-I777] Entropy512:
That jives with some of designgears' experiences - he was having issues with an exchange server inhibiting deep sleep too.

I think it may be partly a server configuration issue. I've also heard that Hotmail calendar sync is a major battery hog, but having everything BUT calendar synced is OK.

Even gmail will sometimes go nuts on the battery in weak-signal conditions where the data connection drops frequently - but not THAT nuts...
[AT&T Samsung Galaxy S II SGH-I777] jrl022:
I had thought about the potential of it being something server related. But that doesn't necessarily agree with how I really didn't have this problem on my DroidX when it was set to "push" and connected to the same Exchange Server.

It just seems like this would be more widely documented if every GSII that had an Exchange account set to "push" had this same issue. This is a pretty popular phone world-wide.

I did find one thread on the I-9100 forum that reported very similar drainage issues with an Exchange account, but it was a short thread without much outcome.
[AT&T Samsung Galaxy S II SGH-I777] XGhozt:
I found an application called "Autostarts". I was able to disable just about everything from starting up and running in the background. I'm also using "Advanced Task Killer" and my battery life has gone from 4 hours of use to 12 hours of use.

Please also remember that it's important to drain the battery every once in a while to get an accurate reading. It's also important to not over charge it because that can hurt it in the long run.
[AT&T Samsung Galaxy S II SGH-I777] Entropy512:
NO NO NO NO NO! Please stop blindly applying HTCisms to Samsung devices.

Our fuel gauge's recalibration procedure is simple:

Pull battery

Reinsert

That's it. It has no provisions for nonvolatile statistics storage.
[AT&T Samsung Galaxy S II SGH-I777] jrl022:
Ugh. Well it looks like just changing the Exchange Email sync from "push" to once every hour (and once every four hours off peak) hasn't changed much. Email is still keeping my phone awake a ton of the time and blistering through my battery at pretty much the same rate. Went to bed last night at 10:45pm with 64% remaining and woke up at 6:30 with 14%. I can't be losing half my battery during eight hours of complete idle.

The first discharge above was yesterday's normal discharge. Total screen time on that discharge was a little under 1h 20min. And that was with Exchange set to 1 hour polling for most of the day. The second discharge was the aformentioned eight hour "idle" period while I was asleep.

So I suppose something's wrong with my mail program. I'm gonna factory reset it this morning and leave Exchange sync off the device for the rest of the work day to monitor battery usage - just to make sure that's the problem.

This really blows because I've really enjoyed this phone other than watching the battery gauge read like a countdown timer.