[Q] Device crashing randomly while not connected to a power source - Galaxy S II Q&A, Help & Troubleshooting

Hello there,
My Samsusng Galaxy S2 (i9100) has recently stopped working as it is supposed to. While I tried debugging the issue in any way I could, I figured out I might get some help over here.
At any time that the device itself isn't connected to a power source (USB cable [adb] or the charger), it randomly crashes (the screen turns black and I have to turn the phone on again). I also must say that this problem doesn't happen while on the recovery screen (CWM based recovery).
At first I thought this may happen because I've installed a pretty old version of Cyanogenmod (the cm11 installer version), so I installed the recent monthly build, but the issue still persists. I've tried debugging the device wirelessly (because when it was connected to a power source it never crashed), so I played a game which makes the CPU work abit, and I thought I'll get a crash log - which I didn't get. The last radio signal I got from the phone was this:
I/LibraryLoader( 2817): Expected native library version number "",actual native
library version number ""
I/chromium( 2817): [INFO:library_loader_hooks.cc(116)] Chromium logging enabled:
level = 0, default verbosity = 0
I/BrowserStartupController( 2817): Initializing chromium process, renderers=0
D/TinyALSA-Audio Hardware( 1855): audio_hw_get_mic_mute(0x4003e938, 0x4126daeb)
D/BluetoothManagerService( 2205): Message: 20
D/BluetoothManagerService( 2205): Added callback: android.bluetooth.IBluetoothMa
[email protected]:true
D/BluetoothAdapter( 2817): 1112752792: getState() : mService = null. Returning
STATE_OFF
D/libEGL ( 2817): loaded /system/lib/egl/libEGL_mali.so
D/libEGL ( 2817): loaded /system/lib/egl/libGLESv1_CM_mali.so
D/libEGL ( 2817): loaded /system/lib/egl/libGLESv2_mali.so
E/ ( 2817): Device driver API match
E/ ( 2817): Device driver API version: 23
E/ ( 2817): User space API version: 23
E/ ( 2817): mali: REVISION=Linux-r3p2-01rel3 BUILD_DATE=Wed Oct 9 21:05:
57 KST 2013
W/chromium( 2817): [WARNINGroxy_service.cc(890)] PAC support disabled because
there is no system implementation
I/chromium( 2817): [INFO:CONSOLE(0)] "Document was loaded from Application Cache
with manifest {URL}
k-core-v40.appcache", source: {URL}
d/sdk/native/sdk-core-v40.html (0)
I/chromium( 2817): [INFO:CONSOLE(0)] "Application Cache Checking event", source:
{URL}
l (0)
I/chromium( 2817): [INFO:CONSOLE(0)] "Application Cache NoUpdate event", source:
{URL}
l (0)
W/chromium( 6284): [WARNINGroxy_service.cc(890)] PAC support disabled because
there is no system implementation
I/chromium( 6284): [INFO:simple_index_file.cc(437)] Simple Cache Index is being
restored from disk.
D/Yamaha-MC1N2-Audio( 1855): yamaha_mc1n2_audio_output_stop()
D/Yamaha-MC1N2-Audio( 1855): yamaha_mc1n2_audio_route_start()
Click to expand...
Click to collapse
I've tried tracing the log files the system automatically creates in the ./system folder, but I couldn't find any useful information except from some deamon crash logs.
I tried resetting the dalvik cache, reinstalling my ROM manually (adb sideload), preforming a complete factory reset and wiping cache partition, and yet it didn't work.
I'm quite sure the issue relates to my phone's battery (which overheated a bit when I used it for a long time), but I'm still not completely sure this is the issue, so I would like to hear your suggestions.
Thanks in advance,
Eden

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Eden Campo said:
Hello there,
....
I've tried tracing the log files the system automatically creates in the ./system folder, but I couldn't find any useful information except from some deamon crash logs.
I tried resetting the dalvik cache, reinstalling my ROM manually (adb sideload), preforming a complete factory reset and wiping cache partition, and yet it didn't work.
I'm quite sure the issue relates to my phone's battery (which overheated a bit when I used it for a long time), but I'm still not completely sure this is the issue, so I would like to hear your suggestions.
Thanks in advance,
Eden
Click to expand...
Click to collapse
I also read your logcat or yeah the part of it and it seems all to be fine, normal lines.
I don't own the S2 anymore and I didn't had the issue. But I suggest to try somethings first before buying a new battery.
Try another rom instead of cyanogenmod, Cyanogenmod is supporting Alot of devices and it's not really good specific for devices so I suggest to try one of the roms from the development forums.(Cyanogenmod always have bugs.)
Try to flash back to stock with odin
Try to borrow a battery from a friend and see or you still have the same problem
Remove the battery out of the phone and leave your phone without a battery for like 1-5 minutes.
It could be maybe the battery that it got issues cause the S2 is not the newest phone anymore and hardware also has a lifetime sadly. But your screen goes black and your device goes off right?