What was found
LAV EMERG LIGHT: EMERGENCY BATTERY #4 NOT CHARGED AND DID NOT CHARGE AFTER FOLLOWING THE EMERGENCY LIGHTS FAIL PREFLIGHT TEST PROCEDURES IN THE CESSNA -AFM. WE RAN APU FOR 2 CYCLES OF 30 MINUTES EACH AND BATTERY DID NOT CHARGE. CORRECTIVE ACTION: REMOVED THE #1, #2,#3 & #4 EMER. LIGHT PWR SUPPLY DUE TO THE LAV. EMERGENCY POWER PACK NOT CHARGING AND INSTALLED A NEW #1, #2, #3 & #4 EMERGENCY LIGHT POWER SUPPLY IAW THE CE-680A AMM 33-50-06 FUNCTIONAL TEST IS GOOD WITH NO DEFECTS NOTED #1 EMERGENCY LIGHT POWER SUPPLY PN OFF: CBS28-1 SN OFF: 005691 PN ON: 6430028-1 SN ON: D25-12017 #2 EMERGENCY LIGHT POWER SUPPLY PN OFF: CBS28-1 SN OFF: 5934M PN ON: 6430028-1 SN ON: D25-12018 #3 EMERGENCY LIGHT POWER SUPPLY PN OFF: CBS28-1 SN OFF: 1024M PN ON: 6430028-1 SN ON: D25-12015 #4 EMERGENCY LIGHT POWER SUPPLY PN OFF: CBS28-1 SN OFF: 008805 PN ON: 6430028-1 SN ON: D25-12016