As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT IN BASE MAINTENANCE: INOP BATTERY EMERGENCY POWER SUPPORT UNIT 12WL IN PAX CABIN. MAINTENANCE REPLACED BATTERIES OF THE EMERGENCY POWER SUPPLY UNIT (EPSU) 12WL IAW A320 FAM AMM 33-51-38-000-002-A AND A320 FAM AMM 33-51-38-400-002-A.