As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON POWER UP AT THE GATE EMERGENCY LIGHT BATTERY FAULT MESSAGE APPEARED ON EICAS. FERRIED AIRCRAFT FROM ORD TO IND FOR MAINTENANCE. MAINTENANCE TROUBLESHOT THE AIRCRAFT AND FOUND THE NR 4 EMERGENCY BATTERY PACK FAULTY. REMOVED AND REPLACED NR 4 EMERGENCY BATTERY PACK PER AMM. OPS CHECK GOOD.