As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS IN BASE MAINTENANCE: DURING PS CHECK FOUND EMERGENCY LIGHT INOPERATIVE FOR EMERGENCY POWER SUPPLY UNIT 11WL EXIT LEFT. REMOVED AND REPLACED BATTERY OF THE EMERGENCY POWER SUPPLY UNIT 11WL AND PERFORMED OPERATIONAL CHECK OF EMERGENCY POWER SUPPLY UNIT IAW A321 AMM 33-51-38-000/400-002-A.