As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: EMERGENCY LIGHTS FLASHING AT DOORS 4 AND 2. MAINTENANCE REPLACED THE BATTERY FOR EMERGENCY POWER SUPPLY UNIT 13WL (AALA202308033907) AND THE BATTERY FOR EMERGENCY POWER SUPPLY UNIT 15WL (AALA202308036553) PER AMM 33-51-38.