Battery & fridge question

Wattie

New Member
May 14, 2011
4
0
0
Hi all - another question from someone new to this whole caravanning scene. We will be heading off on our Central Oz trip at the end of August and I need to sort out the following. What is the best set-up for running the 3 way fridge in the van whilst driving? Do we:
1) Run it off the vehicle battery and run the risk of flattening this battery
2) run it off the vehicle battery but install an isolator so that when the vehicle is switched off the power to the fridge is off also and therefore won't flatten the battery
3) Have a dual battery system installed in the vehicle to power the fridge in the van
4) Install a bettery in the van which would run the fridge and be handy if we were staying at unpowered sites.
We won't be running an Engel or Waeco in the car whilst travelling either.
Any advice appreciated!

Cheers,

Wattie
 

bully66672

Member
Jun 30, 2011
98
13
8
Melbourne
I have a red arc battery isolator on my vehicle which works great.
While towing, the car keeps the fridge cool.
As soon as you turn off your car the power is cut by the isolator so that you don't flatten your cars battery.
It is great to have a battery in your caravan for lights and small 12 volt appliances but it would not keep your fridge cool for very long due to the amount of charge required to run.
When I arrive at destinations without power I run the fridge on gas which works great.
While running the fridge on gas I usually have the controller set at 4 which seems to be good.
It would be good to have a second battery in your car if you could as a back up.


Cheers
 

boots33

Well-Known Member
Jun 25, 2011
708
679
93
Maudsland Gold Coast Hinterland Qld
Hi all - another question from someone new to this whole caravanning scene. We will be heading off on our Central Oz trip at the end of August and I need to sort out the following. What is the best set-up for running the 3 way fridge in the van whilst driving? Do we:
1) Run it off the vehicle battery and run the risk of flattening this battery
2) run it off the vehicle battery but install an isolator so that when the vehicle is switched off the power to the fridge is off also and therefore won't flatten the battery
3) Have a dual battery system installed in the vehicle to power the fridge in the van
4) Install a bettery in the van which would run the fridge and be handy if we were staying at unpowered sites.
We won't be running an Engel or Waeco in the car whilst travelling either.
Any advice appreciated!

Cheers,

Wattie


Hi Wattie

The most practical thing to do would be to fit another battery in the van as in option 4 at least you can then have lights etc while you are disconnected from the van. This also reduces the risk of running your car battery flat which is no fun if you are at an isolated spot. There is however a bit more to it than just fitting the battery i have a list of a few things you should consider below.

The battery should be a sealed deep cycle type and fitted in a proper plastic case made for the job and securely mounted and well ventilated..

Any power run from the van battery must be fused as close to the battery as practical.

The wire running throught the car should be around 6mm and only get power when the ignition is on (not accessories). this removes the chance that you could flatten you car battery by accident. You will have to use a relay to achieve this without putting extra load on your ign switch. It must also be fitted with a fuse or circuitbreaker as close as practical to the car battery. you should also run a similar size earth lead from the car battery negative at the same time to ensure a good earth. you can buy twin sheathed cable from most auto electrical outlets. it is just as easy to run two wires as one.

to connect to your van you will need some kind of plug arrangement. Two common types are the Anderson Plug and the 12 pin trailer plugs now available with 7 normal pins and a row of 5 heavy pins fo power etc. debate rages over which is best, jayco now fit the 12 pin as standard but if you already have a plug fitted it may be just a easy to use the Anderson.

you must ensure that power from the van battery cannot get back to the car battery. While the car is starting this could could blow the fuse if the car battery was flat as it would try to use the van battery to start from. you can do this in a number of ways from a simple blocking diode to some very fancy isolation devices.

You may also like to consider a low voltage cutout device for you van battery. This will automaticaly disconnect the battery from the load before it gets flat enough to cause damage to your battery.

You might also like to add a way to trickle charge your van battery when it is plugged into mains power

We have just picked up our expanda and have a battery fitted in the van. Jayco use a Setec unit to achieve most of the items above. There is a wide range of products available in the market at an even wider price range so it would probably pay to talk to your Jayco dealer or an Auto electrican to see what they think. Check your van it may already have some of the abilities built into it's current power unit.
 

wizzerwazza

Member
Sep 20, 2010
55
5
8
perth, nor
Probably option 2 is a good way to go. Run some heavy gauge wire from vehicle battery through an isolator to rear of vehicle. Run heavy gauge wire from 12v fridge wiring to towball area and connect to car via an anderson plug. This is how mine is done except i dont have an isolator (but should). Dont forget to put a fuse in at start of wiring. 3 way fridges draw heaps of current so when stopped for a while better to changeover to gas.

wizzer
 

Moto Moto

Forum Moderator
Staff member
Mar 15, 2011
1,553
567
113
The Gong
I have a red arc battery isolator on my vehicle which works great.
While towing, the car keeps the fridge cool.
As soon as you turn off your car the power is cut by the isolator so that you don't flatten your cars battery.
It is great to have a battery in your caravan for lights and small 12 volt appliances but it would not keep your fridge cool for very long due to the amount of charge required to run.
When I arrive at destinations without power I run the fridge on gas which works great.
While running the fridge on gas I usually have the controller set at 4 which seems to be good.
It would be good to have a second battery in your car if you could as a back up.


Cheers

I have the same set up.

But I also ordered my van with an anderson plug, which charges the battery, and the 90L fridge runs off the power in the 7 pin plug. I have a redarc isolator connected to both the anderson plug and power in the 7 pin, so when i stop the isloator cuts power to both.
So when driving the fridge runs off the car battery, and the power is cut when the car is off.

I have only been away twice with this setup, but seems to work perfectly:thumb:
 

Wattie

New Member
May 14, 2011
4
0
0
Wow - some detailed advice here. I'm thinking along the lines of having a second battery installed in the vehicle and an isolator installed so as not to drain the battery when the vehicle is stopped. I'll speak to an auto electrician tomorrow for some costings and advice. There is a 20 Amp fuse installed in the van marked battery - I guess that might make wiring a battery into the van a little easier???
Still so many things to do.
Thanks all for your input.
Cheers,
Wattie
 

Bank of Dad

Well-Known Member
Jul 20, 2011
713
361
63
Kilmore, VIC
What is the best set-up for running the 3 way fridge in the van whilst driving? Do we:
1) Run it off the vehicle battery and run the risk of flattening this battery
2) run it off the vehicle battery but install an isolator so that when the vehicle is switched off the power to the fridge is off also and therefore won't flatten the battery

We have a relay fitted to our Prado, done when the Brake Controller wired up, that isolates the battery when the engine is off.

Seems to work OK.....love to do a DBS - its the way to go for safety as well, unless you are in a convoy of 2 or 3 vehicles.