Battery Charger - Solar - DuoCaracteristicas: Charges and maintains a 12V battery during the day and monitors and displays the battery state of charge at night The solar panel is where the sun is and the charger is where the battery is, so that you have immediate information on battery condition at hand right where it matters most Saves flat batteries from as low as 4V with its unique pulse action The reach distance between battery and panel is 124" (Extenders sold separately)