As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT GROUNDED. ALL BATTERY PACKS FOR THE EMERGENCY LIGHTS FAILED DURING THE TESTS. REF TASK 3500444 2000-0105. REMOVED AND REPLACED ALL BATTERIES FOR THE EMERGENCY LIGHTING. REF TASK 33-51-51-962-015. OPS CHECKS PERFORMED - PASSED. REF TASK STEP 3E (4).