As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT NOT GROUNDED. EMERGENCY POWER SUPPLY UNIT EMERGENCY BATTERY L FAULT DURING OPERATIONAL TEST FOR SLIDE CHANGE. REMOVED AND REPLACED L3 DOOR EMERGENCY BATTERY IN THE OVERHEAD PANEL PER AMM 33-51-38. SATISFACTORY OPERATIONAL CHECK ACCOMPLISHED.