Version 3 Brass Monkey Lithium Batteries Charger 12.6VThis 12. 6 volt Mains Power Supply charges Version 3 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.