Koolatron F70110 12 Volt Battery Saver Prevents drainage of your car battery, Works in any vehicle with a standard 12 volt outlet, Black

Give yourself peace of mind with the Koolatron 12 volt Battery Saver. When plugged into your vehicle's cigarette lighter, the Koolatron 12V Battery Saver senses when your vehicle voltage drops below 11 volts. The Battery Saver then shuts off the current to all accessories plugged in, preventing further drainage. It will reconnect automatically when you start your vehicle. The 12 V Battery Saver gives you peace of mind by ensuring you will always be able to start your vehicle.