What was found
IN FLIGHT, WITH EMER LTS IN THE ARM POSITION, ALL MAIN CABIN EMERGENCY LIGHTS ARE ILLUMINATED. ABOUT 50 MIN INTO THE FLIGHT AT FL400 THE CABIN EMERGENCY LIGHTS BEGAN TO FLICKER. REPLACED THE NO.1 AND NO.2 EMERGENCY LIGHT BATTERIES WITH TESTED UNITS IAW PHENOM 300 AMM TASK 33-52-01/400. PERFORMED OPERATIONAL CHECK IAW TASK 24-41-00-860-802-A/200. ALL OPERATION IS NORMAL AT THIS TIME P/N OFF 6450LS-00 S/N'S ON 001181,001526,001693,001102. .