Waeco in back of Car

Do it properly and buy a Raps 12 and connect it to the second battery Has much heavier wiring . A ciggy sockets wires are far too light to satisfactorily run a fridge.
https://www.autoelec.com.au/ssl/public_autoelec/store_v4/product_detail.asp?id=315&cat=30
http://www.getawaeco.com.au/index.php?action=view&com=com_products&itemid=115

Can you clarify your question, you indicate that the fridge can be connected to a cigarette lighter but it will only be powered when the car is running, this sounds like the cars standard OEM power outlet. Then you ask would it be better to connect to the second battery which then sounds like you have a dual battery system installed?

Assuming the waeco is a compressor type fridge it should be connected to the aux battery if you have one and run all the time?

Cheers

Yes, probably best to fit a dual battery system of some description.

If you are running it off the ciggy plug, then the fridge will be working it's ass off just to cool down to the set temperature, then when you stop it will immediately start warming up again, which pretty much makes having a fridge pointless. You would be better off with an esky and a bag of ice.

If you want to do it on the cheap, don't want to haul a battery and if you get infrequent use, then a jumper pack might get you by, but you would want to up the diameter of the wiring running to the back end to ensure you get more than enough power to charge the jumper pack and also keep the fridge ticking over.

An isolator under the bonnet and cable running to a Anderson plug in the cargo area is what I have. I installed it myself and all up it was around $150, battery and battery box was extra. This way I can plug in my battery and charge that while I drive, while running the fridge off the 2nd battery the whole time. When I don't need the battery, then it sits in the shed on a trickle charger.

Croc clips are not the best solution as at some stage you are going to need to put some electrons back into that 2nd battery, you may as well have it hooked up all the time. Much less chance of it tipping over, shorting, venting as well as having to unpack everything to get to it.

Hi Johno
This is a solution I found worked quite well. I bought two more things from Waeco.
1) a RAPS-12R-U2. This is a heavy duty cigarette/Hella plug that connects directly onto your battery. The unit itself can be switched to deliver power either all the time or only on when the engine is running. I chose the latter for obvious reasons.
2) A CoolPower RAPS36 #RAPS36. This is a compact 36AHr deep cycle battery and had enough juice to run our 35L fridge overnight quite easily. It comes with a lead so you can plug it into the above RAPS-12R so that it is charging while the engine is running.

Plug your fridge into the battery with the normal fridge lead. The fridge runs only off the battery. The battery is being charged whenever the car is running. The battery will run your fridge easily overnight.

I ran this for a few years without any dramas at all.

cheers

Kevin

Do it properly.

Run another power cable and fuse from the second battery to a good quality cigarette lighter socket down the back and plug the fridge into it. That way the fridge won't overheat in the summer when you are in the supermarket etc etc. Don't muck around with temporary things like alligator clips etc.

Sure you may have to get an auto-electrician or mate to help but at least the meat and stuff won't go off. Then you can continue your trip and not go back to civilisation.

And if you are going to add, at some time, driving lights, accessories and some lighting for the camp at night you could add a separate fuse box and run all the camping and 4wd accessories from it. Labelling each fuse also helps with fault finding.

Plus as said above, if not done already add something like a Redarc isolator between the batteries. This will protect the crank battery.

I won't go on any more other to say that; temporary and cheap jobs break at the most inopportune moments.

Phil

Also if you are going to be running the fridge off the car battery as a regular thing and don't want the expense of a dual battery setup you should probably look into fitting a dual purpose battery get the largest amp hour one that fits into the tray. I used a single battery setup for quite a few yrs in my patrol without any problems you just need to figure out the power consumption of the fridge and how long it will run without flattening the battery. I use to get 2 days out of a 105 ah Supercharge allrounder running a 47ltr Evakool definitely worth the money.

I agree with many in this forum, the best and in the long run the cheapest alternative is a second battery.
If you are using the Cig socket in your car for prolong periods of time may result in issues, that may 1/. Damage the Vehicles electrical system 2/. Compromise your fridge's design capabilities.
The location of this second battery can be fixed..ie into the structure of the vehicle via a battery tray or portable via battery box with an isolator.
The size of this second battery will depend on the size of your fridge and other auxiliary items you want to run.
There are people in this forum that will provide much detail in solving your delima.