As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: WHILE ACCOMPLISHING OPERATIONS CHECK OF EMERGENCY LIGHT TEST PS CHECK PAGE 34 FOUND FAULT CODE EMERGENCY POWER SUPPLY UNIT 14WL MID RIGHT. TROUBLE SHOOTING FOUND FAULTY BATTERY AT 14WL REPLACED BATTERY AS PER AMM 33-51-38 ACCOMPLISHED ALL REQUIRED CHECKS OPERATIONS NORMAL.