Share your experience!
Finally my ARC S is giving execellent battery backup.
Almost double battery backup:smileylaugh:
Please find this thread below
http://forum.xda-developers.com/showthread.php?t=1413262
Please check this thread from XDA.
"
Hello guys
Today i am going to give you a very small tip may you people like it ....
i used 2.3.4_283 firmware in Arc for a long time , after that i flashed 42 firmware and feel that its drain battery fast as compare to 283 firmware either you are using you phone or it is in deep sleep mod
Then i flashed 58 firmware and after that 62 firmware but battery drains still fast
then i try one thing on my arc i get the Kernel from 283 firmware and flashed it on all three version of firmwares ( 42, 58, 62 ) and notice that the issue of fast battery drain is solved it is only because of 283 kernel "
now i am using 42 firmware with baseband 64 and kernel from 283 firmware
It does'n matter what ever the firmware you are using or what ever the baseband you are using ....... you need to use kernel from 283 firmware only for low battery drains ..............
i attached kernel from global generic wold 283 firmware also...
How to flash different Kernels
1) connect your phone into fast boot
2) open cmd
3) fastboot devices
(write this command and enter it to check your phone is connected in
fastboot or not)
4) then write this and enter
fastboot flash boot kernel.sin
Done ..........
remember to copy kernel .sin file in that folder from where you are going to launch cmd
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I have done this already and my ARC S works completely fine.
This how I have done it
-----------------------------------------------------------------------------
Requirements:
Steps
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Step 1: Download the LT18i_4.0.2.A.0.58 (2.3.4) _HK firmware
Step 2: Download the Kernel file
Step 3: Copy the “Kernel.sin” file
NOW OPEN FLASH TOOL FOLDER. YOU SHOULD SEE FIVE FOLDERS WITHIN IT.
Step 4: Copy the LT18i_4.0.2.A.0.58 (2.3.4) _HK folder
Step 5: Paste the folder within firmwares folder
Step 5: Click on Flash Tool .exe
Step 6: Click “select source folder” (click on the doted button)
Step 7: Select the folder that you have copied in Flash Tool/ firmwares folder (LT18i_4.0.2.A.0.58 (2.3.4)
Step 8: You will get all the file list on the left side
Step 9: Select all file and click on the “Right Arrow” button.
Step 10: Put anything in this 3 boxes (doesn’t really matter)
I have put following
Step 11: Click OK and wait.
Step 12: When you will see the "Finished bundle creation" message, then the firmware is ready.
Step 13: Check the Flash Tool/firmwares folder. You should get your new firmware “LT18i_0.58_283_Stock SE.ftf” file there.
IF you DO, then just flash your device with this firmware.
All done.
**Important**:
Message was edited by: Auni
Solved! Go to Solution.
No. 1: The phone is asking for an update because you are using an old "KERNEL". If you update now, it will revert back your kernel version 0.58 stock. So again the battery drain problem might occur. Your firmware version is 0.58, so it's fine, do not worry about the kernel.
So it is upto you, using an old kernel won't affect your phone function.
No. 2: After pressing this *#*#7378423#*#* check model info and if it says LT18i, then it should be fine.
No. 3: If you want the latest firmware update 0.62, then it is mentioned above @ uliwooly-wooly post.
Here's the link again.
http://talk.sonyericsson.com/thread/29197
The update process is well explained there. Please check.
No. 4: The latest update of 0.62 firmware may not be able to combined with the old kernel. It didn't worked for me. So I stick with the old kernel.
**** I have checked, the above kernel combination trick works only with 0.42/0.58 firmware version now.
Excellent!
I am using 58 firmware with .283 stock kernel.
1. You can use the above “command prompt” method to change kernel
OR
2. You can flash the kernel using the Flash tool using fast boot
OR
3. You can combine the .283 kernel & .58 firmware and create a new firmware. Then flash your phone with this new firmware.
I followed the 3rd step.
My ARC S giving great results after flashing with this.
Notes:
I'd added a pre-rooted update
Arc/S LT15i/a -18i/a 2.3.4 4.0.2.A.0.62 (pre-rooted version too)
does .62 version works well with .283 firmware?
It loops but I'll keep trying
everything gone over my head 
mm, you mean that works with Arc S without any problem? That's great!
I have a LT18i with .42 version. my Arc's battery sometimes really disappoint me, bust still i wait for the final result. keep up.
After using this combined Firmware and Kernel, following is the result on battery performance.
After 8 hours of normal use, Still 85% battery left. In this whole time my display was set on 40%.
If see closely that, the phone signal was also quite weak for sometimes, so there was some pressure on the battery as well. Still 85% left.:smileyhappy:
Previously after same amount use I had 65-70 % battery left max.
So the above technique works for me.:smileyhappy:
nah , its normal for me...
i get somewhat same battery without doing this all 
moreover , your phone was not much awake \ screen on..
but if you believe it worked then who am i to say..