As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT IN BASE VISIT: EMERGENCY POWER SUPPLY UNIT AT LOCATION 11WL BATTERY FAILED EPSU SYS TEST IN REFERENCE WITH JOB CARD 26L00005062. REMOVED AND REPLACED EMERGENCY POWER SUPPLY UNIT BATTERY AT LOCATION 11WL IN REFERENCE WITH AMM 33-51-38, OPERATIONAL TEST PASSED.