that is hard question for everyone as battery usage is quite subjective and depends solely on how u use it, but people are saying at least on normal/medium usage, it should at least withstand a day long and with less usage maybe up to 2 days.

question regarding flashing or rooting is easier to answer and quite easy to do also as long as u can read English and understand English pretty well, the guide on the front page is also quite useful although not quite updated.

Now this is way out of topic of this thread, but I suppose, eventually one of reason people root to is get the better of their battery  by freezing and stuff, so I try shed my little experience. Bad news, you have to read up a few threads , maybe 40 pages in all to really know what's happening.

And If u scare it will brick by flashing around, its tough. Sooner or later you need to cross that bridge to get some goodies.

But for better battery you can try this without flashing ROM.

1. Root your phone with Doomlord method. Its either work or dont work only, wont brick ur phone.
2. Once rooted , you'll have superuser app to grant root permissions.
3. Download & install titanium backup pro . You can google around. Sorry cant give u links to crackware. Better buy it but its your choice.
4. Download BetterBatteryStats ( BBS). There is a free version on xda.
5. Download Setcpu - you can buy it or get the xda version free.
6. Get yourself JuiceDefender / JuiceDefender Ultimate. ( JD)
7. Get yourself Autostarts (AS)

There are many threads on xda , some people say use BBS, dont use JD and setcpu and there is another group that swear JD/SetCPU is good. What I did is to combine all  -  and feel free to experiment on your own. This is not the only way you'll save battery.

1. Use TitaniumBackup to freeze all unused apps that come preinstalled. Check thru and see which one you really need. I have frozen Accuweather,Allshare,Android Live Wallpaper,APMobile,Books( if u have it),unused fonts,Days,Email 1.0,Email 3.0.0.1,GameHub,Homescreen Tips,IM,Kobo,Livewallpaper picker,Maps, MiniDiary, News, Oceanwether, OMACP, Readers Hub,Samsung Apps/UNA,Entire SNS,Social Hubs,streetview,Windyweather, yahoofinance,Zinio Reader. You choose what u really need , rest just freeze it. All of the above I dont need or have alternatives.

2,I turn off stuff in settings, accounts and sync, I turn off auto-sync, I turn off motion ( i dont need it), in Location/Security, I turn off "Use wireless network", in Privacy, I turn off "back up my data". Turn off auto brightness and anything else that may suck battery. There are tonnes of articles online search, fiddle and experiment.
3.Then I charged my phone and used BBS to see what is still keeping my phone "awake". Most times, its friendcaster app. I adjust the settings for friendcaster and other apps. Again, pls read thru BBS thread in xda.
http://forum.xda-developers.com/showthread.php?t=1179809 - you can read a few pages in front and back.

4.I use setcpu and apply profiles that cap the cpu when screen is off and when battery is getting low.
Read here for start http://forum.xda-developers.com/showthread.php?t=1158102

5.I used JD Ultimate and settings from forums. See here but feel free to research and experiment and understand what you are setting.
http://www.villainrom.co.uk/forum/showthre...ender-(Ultimate

6. Of the remaining apps that are not frozen, I use autostarts, to turn of "event triggered starts". I have a very lean startup and most apps run only when i click on them. they dont autostart as they were programmed to do. You can start with a few and experiment as you go along.
With rooted stock firmware, with light-moderate use, I can stretch my battery to about 32 hours. Gmails, Friendcaster checks maybe 10 times, music for ~20-30mins,  some games (Angry Birds) , watch a few song video, many many SMS, a few calls, and check this forum online maybe 20 times. Also sync my office email with Roadsync 3-4 times manually. JD "claims" it has helped increase my battery about 1.8x. But 32 hours is not repeatable many times. Occassionally I get 24 hours,26 hours, 22 hours. Even with Juffo 2.1 is about the same.

Now I am rubbing my hands with glee since its mentioned that superatmos has tweaked power management. I really wanna see how long the battery lasts. So the above is my small experience . I been using android only ~ 2 months now. My biggest shock migrating from my Nokia N8 to SGS2 is battery life. Otherwise no complaints.

Just as i was asking about overheating issues...saw this news...

http://www.tomsguide.com/us/samsung-galaxy...news-13390.html

well since G variant is not as fast as his non-G brother i don't think the heat problem wont be haunting us... my G even i use for a long time usually gaming the battery temp only around 41-42c only

Yes, for I9100G

What you'll need;
1. Download DooMLoRD's Easy Rooting Toolkit from here; http://forum.xda-developers.com/showthread.php?t=1321582. I've used the version 1, but I think version 2 should also work.
2. Samsung driver for android phones installed or KIES installed

The idea;
Using Android Debug Bridge (adb.exe), you'll push zergRush exploit tools to crash the ADB interface and force it to reboot into root mode, accept Superuser and Busybox package which will be installed into your phone. Thanks DooMLoRD@XDA! Sound complicated? No, not really, just follow the steps below!

The Steps
1. Extract the DooMLoRD file. I've used the version 1, but I think version 2 should also work.
2. You'll need to edit a file alittle bit to make sure it work with SGSII I9100G, otherwise nothing will happen. Open the file "runme.bat" with Notepad (right click, open with, find notepad) and find the line that contain "adb wait-for-device". There should be 2 instances of that line, NO NEED TO STARE AT THE CODES AND GIVE YOUR SELF A HEADACHE!, just find the similar line in your files, which I've marked for deletion. Right afterword, please add the "@pause" command as illustrated below;

CODE
@echo ---------------------------------------------------------------
@echo               Easy rooting toolkit (v2.0)
@echo                    created by DooMLoRD
@echo         using exploit zergRush (Revolutionary Team)
@echo    Credits go to all those involved in making this possible!
@echo ---------------------------------------------------------------
@echo  [*] This script will:
@echo      (1) root ur device using latest zergRush exploit (10 Nov)
@echo      (2) install Busybox (1.18.4)
@echo      (3) install SU files (binary: 3.0.3 and apk: 3.0.6)
@echo  [*] Before u begin: 
@echo      (1) make sure u have installed adb drivers for ur device
@echo      (2) enable "USB DEBUGGING"
@echo            from (Menu\Settings\Applications\Development)
@echo      (3) enable "UNKNOWN SOURCES"
@echo            from (Menu\Settings\Applications)
@echo      (4) [OPTIONAL] increase screen timeout to 10 minutes
@echo      (5) connect USB cable to PHONE and then connect to PC
@echo      (6) skip "PC Companion Software" prompt on device
@echo ---------------------------------------------------------------
@echo  CONFIRM ALL THE ABOVE THEN
@pause
@echo --- STARTING ----
@echo --- WAITING FOR DEVICE
@files\adb wait-for-device                                       <== LEAVE THIS ONE ALONE!!!
@echo --- cleaning
@files\adb shell "cd /data/local/tmp/; rm *"
@echo --- pushing zergRush"
@files\adb push files\zergRush /data/local/tmp/.
@echo --- correcting permissions
@files\adb shell "chmod 777 /data/local/tmp/zergRush"
@echo --- executing zergRush
@files\adb shell "./data/local/tmp/zergRush"
@echo --- WAITING FOR DEVICE TO RECONNECT
@echo if it gets stuck over here for a long time then try:
@echo    disconnect usb cable and reconnect it
@echo    toggle "USB DEBUGGING" (first disable it then enable it)
@echo --- DEVICE FOUND
@files\adb wait-for-device                                       <== REMOVE ONLY THIS LINE
@pause                                                           <== ADD A PAUSE COMMAND
@echo --- pushing busybox
@files\adb push files\busybox /data/local/tmp/.
@echo --- correcting permissions
....


Above code might seems alittle bit fuzzy... Make sure you remove ONLY the second "@files\adb wait-for-device" line. ONLY THE SECOND ONE, key?

EDIT: Please add a "@pause" to allow some delay for adb to reconnect to the device which should be around 20 seconds.

Save and close the file.

3. Get your phone to enable USB debugging mode (Menu\Settings\Applications\Development) and enable "UNKNOWN SOURCES" (Menu\Settings\Applications)

4. Exit KIES if it is running. Also stop any phone management software that's running.

5. Plug in the USB cord and let the driver installation finishes

6. Double click "runme.bat", a black and white interface will come out. It should take a looong time for this process to finish... Read the output, you might find it interesting. This process might take 5-10 minutes...

7. (ADDED) You'll find "Press Any Key To Continue...". Please WAIT FOR 20 SECONDS before pressing your keyboard... Then, your phone will restart...

If successful, you'll find the Superuser icon. Yay!

Worked with me flawlessly. Does it work for you? Are you confused? Please share your thoughts

should be no difference, even no binary counter increased as long as u use official firmware

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Added on December 5, 2011, 4:53 pm

u can try Papago X5 and download the latest maps from Malfreemaps.

of course, if not why did i recommend that to u *sweat*
updated maps data for papago X5

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Added on December 5, 2011, 5:53 pm

1. this is rooting need update frequently ? WHAT U MEANT BY UPDATE? ONE TIME RUN ONLY
2. anything i need backup before i do this incase anything wrong.. WITH DOOMLORD METHOD PLUS MEMORY CRASH, NO NEED BACKUP
3. my firmware already 2.3.6 since i bought it a week ago.. do i need to downgrade it and upgrade back to 2.3.6? or now i give a try update it again see got any latest version or not.. NO NEED, STAY AT 2.3.6
i downloaded the latest doomlord v3 use this? USE THIS, MODIFIED ACC. TO FIRST POST PLUS MEMORY CRASH 500MB METHOD
4. samsung driver for android phone is installed>> how to check.. i have kies air installed.. SHOULD BE OK, USUALLY A PROMPT WILL COME OUT IF U PLUG THE PHONE AFTER ENABLE USB DEBUGGING
5. the android debug bridge is what? after rooting only know ? :::::::: READ MORE

PAPAGO X5 IS PAID APPS AND I DO ILLEGAL BUT I DONT CONDONE U TOO ..lols
BINARY COUNTER CAN BE SEEN IN ODIN MODE

I PREFER U GOOGLE ANY TERMS,WHICH ARE NOT UNDERSTANDABLE INSTEAD OF KEEP ASKING . thanks

ps : sorry for the caps, intentionally and unintentionally..LOLS..anyway just google around and ask if u are not sure..

ASKING IS GOOD TOO, BUT ONLY AFTER U GOOGLED AROUND AND FOUND NO ANSWER

haha, so u do read up.. sorry for the confusion.
at that time, actually not superuser app that helped the rooting process, its the high memory usage, it was just a coincidence that at that, it happened just after i  installed the superuser app.

i've tested two times after that, only with high memory usages, basically it will be a success..some other forumers also tried this method too.

just give it a try first, normal try, if not working, try the memory crash method.

i havent tried superrom, but currently i am on superatmos kernel and it is running normal, with no heavy battery drain.

but i suspect, the battery percentage script or whatever inside the framework-res.apk is the devil here. because i've tried to replace mine from the one from superrom, and after that my phone a little bit sluggish. but just a big maybe..lols

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Added on December 5, 2011, 9:41 pm
thought u've been reading around, if u read every posts here, u will know what i meant with memory crash.

superoneclick method is basically the same method with doomlord, both are using the zergrush exploit.

just use the doomlord method, and make ram usage as high as possible like more than 500mb, after that ran the script. no need to turn off the phone.just follow first post thoroughly

as suspected, adb driver for ur device is not installed succesfully.
if u notice, there is a button "change settings" in ur picture, u should try change that to auto windows update for driver and try run the script again.

so u didnt install kies..thats why..lols

did u run apps as many as possible and check with task manager? should be 500mb and above, before u can run the script.. just try it again..

about not rebooting, just turn it off normally, it will reboot itself..dont worry, i've already tested the script like 50 times..lols

glad u did it, welcome to the club..lols
now u can do whatever u want.
gosh, i think i need to write "android for dummies" lols

if u want to flash another rom, like any custom roms out there (only 2 at this moment, juffo or superatmos),
u need to flash another kernel with CWM support.

but if u are satisfied with current rooting only, like u just want to use titanium backup to remove bloatware and any unwanted apps, just stay at where u are..lols

or just plug and let windows done it for you..

p/s : Ketereh too =)

Congrats!! ^o^

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Added on December 6, 2011, 8:09 pm

dun forget to share your ROM after finalized.

should be working assuming u've rooted with the doomlord method (didnt matter which version)

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Added on December 9, 2011, 7:20 pm
not really sure, assumed u've already unticked the "usb debugging" mode, it should work.
but if not, try read the 1st and 2nd post here : http://forum.xda-developers.com/showthread...ight=custom+rom

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Added on December 9, 2011, 7:21 pm
good luck on spamming, but please no trolling..lols

hard to say actually, why u want to unroot actually? if it is me, i just reflash back stock firmware with odin and reset everything..lols

of coz easy mahh..i just did it like 30minutes ago..lols..been testing around, got fed up and re-flash everything to stock back..lols..no usb jig involved ofc....stock firmware will not trigger the yellow triangle or binary counter even using odin.

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Added on December 10, 2011, 12:39 am
of coz it is possible..just as simple as replacing file.
i am not running superrom but from the downloaded rom, i suspect it is inside /system/media/sanim.zip
i think u just back that file as anything like "sanim.zip.bak" and put ur new boot animation, rename to same like sanim.zip too..dont forget the permissions too..check first what is the old permissions

I try many time and i sure i follow all the step.........

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Added on December 11, 2011, 2:48 amCan i knw if i rooted my phone i still can wait samsung release 4.0 and update officially?

Official Malaysia one lar...i just log on to KIES (install KIES yesterday) and check the latest firmware..

Android: 2.3.6
Baseband: I9100GDZKJ2
kernel version: 2.6.35.7

Just run the antutu benchmark and compared the below:

http://10division.com/samsung-galaxy-s2-gt...ow/#comment-525

This blog shows the G running at 1008Mhz at the Antutu benchmark results and scores much lesser 4xxx. Mine managed 54xx (compared to the 56xx of the non-G shown above) and the CPU frequency on mine shows 1200Mhz instead of 1008Mhz.   So the performance is almost on par whereby previously quiet significant gap.

Official firmware yah, no hack-hack coz i dun want to kill my new SGS2 yet.....