As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(AIRCRAFT NOT GROUNDED) EPSU 10WL AND EPSU 12WL BATTERY FAULT DISPLAYED AFTER EMERGENCY POWER SUPPLY UNIT BITE CHECK. REMOVED AND REPLACED EPSU BATTERY 10WL AND 12WL IAW AMM 33-51-38-000-002-A AND AMM 33-51-38-400-002-A. OPERATIONAL CHECK GOOD.