Hi anhnga,
Please STOP using your laptop right away. The battery packs of your laptop (SVF11N18CWP) have the potential to overheat resulting in partial burns to the housing of the PC.
You mentioned from your initial post that you upgraded the BIOS from R0230DE to R0270DE
Has your laptop ever been repaired before?
If YES, then there shouldn't be any issue on the battery after the BIOS upgrade.
If NO, then BIOS upgrade will disable the battery charging function (this is the issue that you currently have)
The link you provided to us explained everything. (refer to the links below)
http://www.sony-asia.com/support/download/610408
http://www.sony-asia.com/support/announcement/588209
For further assistance regarding the repair, please contact the Sony offices/Sony representative offices nearest to your place of residence in Asia Pacific region http://www.sony-asia.com/countryselector.html?hpid=countryselector:AsiaPacific. Due to proximity, they are in a better position to respond to your questions or concerns.
Regards,
Jen