As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SUPPLEMENTAL INFORMATION: EMERGENCY LIGHTS ARE EXTINGUISHING AFTER 10 MIN OF OPERATION ; / [01] PERFORMED BATTERY PACK CAPACITY CHECK PASSED EXCEPT BATTERY PACK M1670 GENERATED NRC FOR REPLACEMENT OF BATTERY PACK M1670; AS PER AMM TASK 33-51-06-200-801.; [02] VERIFIED CORRECTIVE ACTION STEP 1.