This is just a proof-of-concept fix. I dont guarantee any improvement, because i have not much time to test it.
I simply replace battery libs and apps extracted from HKTW.
1. Download "battfix_cwm.zip" (bellow in Attached Files)
2. Copy it to sdcard or sdcard-ext
3. Reboot into CWM recovery
5. Click "install zip from sdcard"
6. Choose zip from sdcard
7. Pick the "battfix_cwm.zip"