As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OPERATIONAL CHECK OF CABIN EMERGENCY LIGHTING BATTERY CAPACITY FAILS WITH MSG "EMER AFT L". REMOVED AND REPLACED AFT L/M ESPU BATTERY IAW AMM 33-51-38- 000-002-A AND 33-51-38-400-002-A AND PERFORMED BATTERY CAPACITY TEST IAW AMM 33-51-00-710-003-A AND NO DEFECT NOTED.