As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, WE SWITCHED PAX SAFETY SWITCH TO THE ON POSITION AND NOTICED NONE OF THE EMER LIGHTS ILLUMINATED. AFTER THE FLIGHT, WE POWERED DOWN AND CHECKED THE EMER LIGHTS LIKE NORMAL, AND THE LIGHTS DID NOT ILLUMINATE WHEN THE EMER LIGHT SWITCH WAS SELECTED TO THE ARM POSITION WHEN THE BATTERY SWITCHES WERE IN THE OFF POSITION. CORRECTIVE ACTION: REPLACED NO1 AND NR 2 BATTERY PACKS. OPS CHECK GOOD. IAW AMM 33-50-00