AC POWER: 220VAC, 50 Hz. BATTERY: Sealed lead-acid batteries only. Maximum charging circuit: 27.6VDC @ 0.8 amp for normal flat charge. Maximum battery charger capacity: 18AH battery. NOTE: Two 10AH batteries can be housed in the cabinet. Larger batteries require a separate battery box. Total DC24V system power: 3.0 amps. Maximum current per NAC: 1.25 amps. Maximum battery charging capability: 18 AH. Resettable four-wire smoke detector power output. Non-resettable power output.