As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY LIGHTING SYSTEM LIGHTS FLASHING IN THE ARM POSITION. TESTED SYSTEM ON GROUND AND DUPLICATED WHAT WE SAW IN FLIGHT. ALL EMERGENCY LIGHTS FLASHING IN THE ARMED POSITION. //SIGNOFF//REMOVED AND REPLACED FWD AND AFT EMERGENCY BATTERY PACKS REF. PHENOM 300 AMM 33-52-01. OPS CHECK GOOD.FWD EMERGENCY BATTERY.