As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(AIRCRAFT NOT GROUNDED) DURING EPSU BAT CAP TEST 13WL BATTERY FAULT. / REMOVED AND REPLACED EPSU BATTERY 13WL PER AMM 33-51-38-000-002-A AND AMM 33-51-38-400-002-A. OPERATIONAL CHECK SATISFACTORY PER 33-51-00-710-001-A AND AMM 23-73-00-740-005-B."