As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING C-CHECK THE NR 4 EMERGENCY LIGHT BATTERY WAS FOUND TO BE DISCHARGED. MAINTENANCE REMOVED AND REPLACED THE AFFECTED EMERGENCY LIGHT BATTERY, THE ENSUUING OPERATIONAL CHECK WAS GOOD. THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.