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 FAULT DISPLAYS DURING TESTING. MAINTENANCE REPLACED EMERGENCY POWER SUPPLY UNIT 16WL (AALA202302221905) AND BATTERY (AALA202302224216) PER AMM 33-51-38. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED.