Dual batteries in your 4WD are the ultimate in extra 12 volt power around your car, especially if running a fridge, camp lights or 12 volt cigga & USB connectivity.
Another option for short stays or weekenders is the 12 volt battery box as seen in this picture. If you don't have dual batteries or can't have your car at the camp site you're on, then this sytem is a beauty.
The battery box has terminals that connect directly to your deep cycle battery (you'll need to buy one). This battery box shown has a 100 amp hour deep cycle battery for camp lighting and/or a fridge. Most of these battery boxes will have a couple of 12 volt sockets and some like this one, also have a meter telling you how much battery life is left. Prices can range between $60 and $500 depending on what extras they have, the one we have here was $70. A deep cycle battery is your best bet as they will recharge and last longer. There is a variety of types to choose from.
We use this AGM deep cycle battery in the back of the Landcruiser as a 3rd battery (moveable). It is charged by a cable that runs from the Dual Battery isolater under the bonet, back to the battery box with a 50 amp anderson plug. At the battery box, we have used 6B&S cable in a 30cm length from the terminals to another anderson plug. Simply connectt the Anderson plug from the isolater lead to the battery box lead and you have charge from the alternater of the vehicle. (when the car is running)
We also installed a 100 amp fuse at the isloater end of the power cable for better protection from faults. Having a set up like this is also great for weekend camping. Simply disconnect the anderson plugs, pick up the battery and put it anywhere around a camp. with the 2 x 12 volt sockets, you can run lights and fridges in any location.
When you pack up, put it back in the car, reconnect, and you will be on your way to charging it up again when you start driving.
12 Volt Battery Options
These Trojen batteries are 6Volt lead acid deep cycle, link the 2 together, and you get 12 volts and 225 amp hours to draw on.