This 12.6 volt Mains Power Supply charges older Brass Monkey fridge/freezer batteries while removed from the fridge. This is a great option if the trip home is too short to fully charge the battery ready for the next use, or where multiple batteries are used alternately. No need to remove the fridge from the vehicle. Just remove the battery from its cradle for charging , or swap it with a second charged battery. Features a 2.1mm DC jack that plugs directly into the battery.Compatible Batteries (These batteries are all discontinued)GH2018GH20195.2AH GH20507.8AH GH205215.6AH GH2054Note:This charger is not suitable for the newer Version 3 Lithium Battery models. Version 3 models require the12.6 Volt Power Supply GH2059