As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: EMERGENCY POWER SUPPLY UNIT (16WL) OVERWING DOOR RIGHT, FAULT ON CENTRAL FAULT DISPLAY SYSTEM DURING EMERGENCY POWER SUPPLY UNIT SYSTEM TEST. BATTERY FAULT LIGHT ON 16WL DURING EMERGENCY POWER SUPPLY UNIT TEST PER AMM 33-51-00. REMOVED AND REPLACED 16WL EMERGENCY POWER SUPPLY UNIT BATTERY PER AMM 33-51-38. A SATISFACTORY OPEATIONAL CHECK WAS ACCOMPLISHED.