As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A MAINTENANCE CHECK THE CLEANING CREW REPORTED THAT THE EMERGENCY LIGHTS WERE CYCLING ON AND OFF. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED THE NUMBER 4 BATTERY PACK AND REMOVED AND REPLACED THE NUMBER 4 CHARGER. THE AIRCRAFT WAS RETURNED TO SERVICE.