As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PREFLIGHT THE CREW NOTICED THE EMERGENCY LIGHTING WAS NOT ILLUMINATING DURING TESTING. GROUND MX CREW DISCOVERED THAT THE EMERGENCY LIGHT BATTERIES WERE DRAINED. UPON REPLACING THE EMERGENCY LIGHT BATTERIES ALL OPS CHECKS PROVED TO BE SATISFACTORY. THE ACFT WAS RETURNED TO SERVICE.