I had the same problem: sometimes the phone itself switched off.
I replaced battery. I bought the new one on ebay with the same capacity as original battery and now I have no problems.
I hope it will help to you.
I tried:
-clean install without gapps
-clean install with gapps (about 6 different packages of gapps)
-dirty install over CM10.2
-different versions of recovery 4Ext
-format partitions as ext3, ext4
-runtime dalvik, ART
It did not help.
Error com.android.phone appears randomly.
This error...
try this:
delete these files
/data/data/com.android.providers.telephony/databases/telephony.db
/data/data/com.android.providers.telephony/databases/telephony.db-journal
and reboot
It helped to me.
Now it runs 12h fine.
ROM is really smooth, just great.
I installed these gapps www.androidfilehost.com/?fid=23269279319195955 but I think it doesn't matter.
Switch to ART - Settings/Developer Options/Select runtime