– Ideal for STD, AGM and GEL batteries from 12v between 2 - 20 AH - Charging current: 0.6A (constant current). - Charging voltage is nominal 12V&12.8V Working range from 4V - 14.4V 0.5V - 14.4V - 4 Step charging process - Operation is fully automatic - Keeps your battery ready for use. - Weatherproof housing with built-in fixing eyes - Usable both indoors and outdoors, lowest temperature for use is -20℃ - Tecmate Optimate 1 Duo Size