Model FT-M1240 FT-M1250 FT-M1260 System Voltage 12V/24V Maximum PV input voltage <54V Rated current 40A 50A 60A External 12V battery recommended solar panel specifications 500-600W/18V 700-800W/18V 800-900W/18V External 24V battery recommended solar panel specifications 1000-1300W/36V 1500-1600W/36V 1800-2000W/36V External battery 12V 150-200Ah 24V 150-200Ah Battery Type(24V*2) B01=Lead Acid Battery 12V B02=Lithium-ion battery 3 series 3.7V=11.1V B03=Lithium-ion phosphate battery 4 series 3.2V=12.8V Charging voltage(24V*2) 14.3V(B01) 12.6V(B02) 14.6V(B03) Low-voltage cut off voltage(24V*2) 10.7V(B01) 9V(B02) 10V(B03) Low power recovery voltage(24V*2) 12.6V(B01) 10.5V(B02) 12V(B03) USB Output 5V/2A Standby current <10mA Working temperatue -35℃~+60℃ Size / Weight /