As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HEAVY MAINTENANCE, DURING PERFORM OPERATIONAL OF EPSU BY TEST CHECK IAWAMM33-51-00-710-001 BATTERY12WL FAULT. THE BATTERY MUST BE REPLACED; (RESOLVED ON W/O: 1480444 TASKCARD: NR-00037 ) REFERENCE AEROMAN WO 2026 217/1 NR 414952 REMOVED AND REPLACED BATTERY OF THE EMERGENCY POWER SUPPLY UNIT (EPSU) 12WL IN PASSENGER CABIN IAW AMM 33-51-38-000-002-A AND AMM 33-51-38-400-002-A AND (PERFORMED OPERATIONAL CHECK OF THE EPSU THRU BITE CHECK IAW AMM 33-51-00-710-001-A TEST IS OK). TECH M AGUILAR 8605312 QC AE347.