As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH-DURING POSTFLIGHT THE CREW OBSERVED THAT THE LAST SECTION OF EMERGENCY LIGHTS WAS NOT ILLUMINATED. IAH-MAINTENANCE REMOVED AND REPLACED THE NR 3 EMERGENCY BATTERY, PERFORMED AN OPERATIONAL CHECK WITH NO DEFECTS NOTED. THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.