What was found
AFTER DOING A FLIGHT AN HOUR AGO EMERGENCY CABIN LIGHTS ARE FLASHING OVER THE ENTRY DOOR AS WELL AS SEAT THREE AND FOUR. FLOOR LIGHTS ARE FLASHING AS WELL. ARRIVED AND POWERED UP THE AIRCRAFT. TURNED ON AND NOTICED THAT THE 2 FWD CABIN EMERGANCY LINGS WERE FLASHING. PUT THE EM. LIGHT SWITCH IN THE ARMED POSITION AND LET THE BATTERY CHARGE FOR 30 MINUTES. AFTER 30 MINUTES SELECTED THE EM. LIGHTS TO THE ON POSITION AND NOTICED THAT THE LIGHTS WERE STEADY ON FOR 5 MINUTES BEFORE STARTING TO FLASH AGAIN. FWD EM. BATTERY POWER SUPPLY WILL REQUIRE REPLACMENT. REMOVED THE DEFECTIVE FWD EM. BATTERY INSTALLED A REPAIRED BATTERY REFERENCING AMM: 33-50-01. CHARGED THE BATTERY FOR 1.75 HRS PER AMM: 33-50-01. OPS CHECK OF THE EMERGANCY LIGHTING SYSTEM WAS GOOD.