As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THIS TEST IS PART OF A HEAVY CHECK INSPECTION-MX WRITE UP. EPSU BATTERY (14WL) REQUIRES REPLACEMENT, FAILED EPSU SYS TEST. REMOVED AND REPLACED EPSU BATTERY (14WL) IAW AMM 33-51-38-000/400-002-A. OPS CHECK GOOD. AIRCRAFT RELEASED FOR SERVICE.