What was found
LAV EMERG LIGHT: ON PREFLIGHT FOUND EMERGENCY BATTERY NOT WORKING. FOLLOWED CHECKLIST AND COMPLETED TWO CHARGE CYCLES. EMER LTS IN THE ON POSITION HAVE NO LIGHTS COME ON. MOST LIGHTS WORK IN THE ARM POSITION EXCEPT; REAR EXIT LIGHT, THE EXIT LIGHT UNDER THE LAV LID, AND THE "SHARK LIGHT" IN THE LANDING LIGHT. POWERED UP AC AND VARIFIED SQUAWK, REMOVED AND REPLACED EMERGENCY LIGHT BATTERY PACK #4 IN THE LAV AREA IAW MM 33-50-06 OP'S CK GOOD. APPLIED POWER TO AC FOR 2 HRS TO CHARGE THE BATTERIES. #4 EMERTIGHT BATT PACK PT# OFF CBS28-1 SN 006686 #4 EMERLGIHT BATT PAC PT# ON CBS28-1 SN 005392