Batty drain issue on CM10.2.1-yuga / Sony Xperia Z - NFC Service using over 50%
You can try the following:

1.Try Calibrating your battery ( few says it is necessary to calibrate your phone after rom installation)


Charge phone to 100%
Boot in to recovery
Wipe battery stats
Reboot and drain the battery completely ( by playing or media or
normal usage)
After complete drain recharge the phone again to 100%


2.Try freezing or renaming or removing nfc.apk and tag.apk (Instead of removing the apk just try renaming them like nfc.apk.bak)