As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HEAVY MAINTENANCE, (REF WORK ORDER 2020-4/1) THE EMERGENCY POWER SUPPLY UNIT BATTERY AT AFT GALLEY AREA MUST BE REPLACED; REF WORK ORDER 2020-4/1, REMOVED AND REPLACED THE BATTERY OF THE AFT GALLEY EPSU (EMERGENCY POWER SUPPLY UNIT) 13WL IAW AMM 33-51-38-400-002-A AND PERFORMED OPERATIONAL TEST OF EPSU IAW AMM 33-51-00-710-001 AND TEST IS OK.