Basically this is my first post on here because it's actually the first time that I couldn't find a thread covering the same/similar problem that I'm experiencing...
Here's my issue:
I've got two batteries for my SGS 2, the standard 1650mAh battery and an extended 2000mAh battery (Official Samsung Extended Battery Kit), which I bought about half a year ago, when the stock one started giving me battery life of only few hours.
Yesterday, when my battery died I plugged it into my PC and booted the phone back up immediately without letting it charge even a little bit because I was in a hurry... Since I started using it right away the battery drained faster than it could charge and died within seconds with the screen flickering.
I knew I wasn't really being nice to the battery so I finally let it turned off to charge...
This was when I noticed that it wouldn't charge at all (no charging indicator), though it did seconds before when it was on.
So I tested different USB cables and sockets --> Not charging.
I replaced the battery with the old one that I haven't used in months --> Charging!
These results prove that the charger itself and the USB port of the phone do work and indicate that the issue is with the extended battery.
Now my question is: Can a battery just break so suddenly and if yes, is it fixable and how? I knew a battery can get weaker with age and become useless this way and that the most common reason for a battery to not charge at all are broken components (usb cable or port) but I never knew batteries could suddenly stop working.
Keep in mind the 'broken' battery is relatively new (5 months) in comparison to the old one which was in duty for 2+ years.
Another thought: Maybe it's a problem with the phone, 'not recognizing' the battery after it had its sudden death?
I hope my description was somewhat clear and thank you guys in advance for your help and suggestions!
P.S. Don't know if it's of any help here but I'm running a cm 10.2 nightly (Android 4.3.1)