Help with understanding the 3 way fridge

[AddItUp]

We are going through the purchase process on a new 17.56-1. This is our first caravan and I have a reasonable understanding of most things, but the 3 way fridge is confusing me somewhat.

If I'm driving along, I assume the car alternator provides power to the fridge. If so, does running the fridge cause any issues for the vehicle charging the normal car battery and the fridge?

What happens when we stop at the side of the road for an hour to have a break? Do I need to swap over to gas? Should there be a 12V battery in there somewhere?

About the only bit I understand is when you get to the powered site and connect to the 240V.

We love the caravan and can't wait to go away on our first trip.

Thanks in advance.

 

[Soaring]

Ok, if you have a 12 pin plug wired for aux power, you can select DC on your fridge so that the vehicle will deliver power to your fridge.
Yes, if you stop for lunch and leave the van connected to the car, it will drain your battery unless you either turn it off DC, or swap to gas.
Generally your 12v van battery (if fitted) is not connected to your fridge . Thought being on 12v they suck too much power.
For me, I cool the fridge down on 240v the day before we leave, fill it with cold food/drink, and turn it off while travelling. It stays cold if not opened too much. When we arrive at our destination we use either 240v if available or Gas. No dramas at all.
Also, generally if you really want to run it on 12v while travelling, an Anderson lead and heavy duty cable with a disconnection device like a duel battery solenoid is recommended.

 

[AddItUp]

Thanks very much Soaring, I appreciate your reply.

 

[fishinglizard]

When I had my van first serviced. I was going to get an anderson plug to fridge. The service guy said i didnt need it. I have the seven pin plug. Switch it to 12v when driving and never had a problem fridge is always cold as. When i stop at rest area i disconect plug from car, turn on gas for fridge, put hot water service on have lunch wash up done. I thinkbthe hot water on tap is my favourite thing in the van.

 

[AddItUp]

Thanks fishinglizard, however, you're making me regret not getting a hot water service.

 

[Xpandafan]

@Soaring and @fishinglizard have hopefully sorted it for you.
Don't run mine on 12v at all. Gas mostly apart from pre-trip chill when it's on 240v @ home or if in a powered CP site for a few days.
Find fridge on gas is very efficient.
We also put gas on for HW and fridge at long lunch stops...mainly because we can!
We have a routine...when we stop, I always walk back along drivers side of tug and van, visual check hitch, chains, plug(s) etc. and turn on gas, check tires, wheel temp., then round back, check tires/wheels on passenger side.
Mrs XF meantime unlocks van, switches on HWS, fridge, and puts on kettle. Then reverse process before heading off again.
You're going to love your new van and you will quickly establish your own routines.
Setting up is similar, after a few goes and a bit of a sense of humour, you'll start to develop a system that suits you, and will run like clockwork. We have shared tasks and individual jobs so that we're set up inside and out at about the same time.

 

[AndrewC]

I ripped mine out because I hated the muck around of it when traveling. The compressor fridge is set and forget!

 

[AddItUp]

Thanks very much @Xpandafan (and also @Soaring and @fishinglizard ...I forgot the "@'s before").
It sounds like you have a well thought out plan. Thank you so much for sharing, it has really helped. I'm sure we will develop one in time too after we muddle our way through the first couple of times.

 

[Izzya123]

I have 17.56.1. installed a second aux battery in car, ext anderson plug & battery isolating solenoid device to car battery. Runs on DC when travelling, don't have to worry about car battery. Way to go but costs......had local auto elect do it after getting green light from Jayco re any warranty issues.

 

[AddItUp]

Thanks @Izzya123 Did you go with that setup to avoid having to swap over to gas when you stop and so you didn't have to worry about accidentally flattening your car battery?
If I don't have your setup, is the car able to charge the normal car battery and power the fridge as we are driving along? I don't know much about electronics, is the alternator able to cope with the extra load?

 

[Stone Stomper]

Depends on how far you want to go, the 3 way will never work to it's full potential running the power supply through the 7 or 12pin connectors due to the fridge needing lots of amps, 10amps + for the 90Lt fridge and 25 amps + for the 150Ltr fridge.

Power through the normal trailer plug will just maintain temp but as we often travel in hot weather I wanted the fridge to cool and cycle on 12v so I rewired the fridge to the van battery with 6mm cable then an Anderson plug between car and van battery being charged via a Redarc BCDC40 which is also a dual battery controller and allows the van battery to be fully charged while driving.

When we stopped for a walk or lunch we would always switch over to gas.

Christian

 

[AddItUp]

Thanks @Stone Stomper Initially we will just be travelling local, so we may get by with the normal trailer plug and switching to gas when we stop for a rest. When we start to explore longer distances, we may leave to look at something like your setup.

 

[macca]

We generally travel on trips no longer than 5 hours away. we just turn fridge on day b4, get it nice and cold. We don't have 12 volt wired to ours, so I just turn ours on gas when we get to destination. I find gas is quicker, I will then turn it on to 240V after a few hours. I have heard a tip when travelling is to take an old soft drink bottle filled with water and frozen the nite before. It will help things to stay cold whilst travelling.

 

[AddItUp]

Great tips @maccayak , thanks very much. We will only be going on short trips initially, so we'll have to wait and see what works best for us. This is our first caravan, so there are many things we need to learn!

 

[Hubble80]

Great tips @maccayak , thanks very much. We will only be going on short trips initially, so we'll have to wait and see what works best for us. This is our first caravan, so there are many things we need to learn!

This is the place to learn stuff!! Welcome to the forum and happy traveling! I have the 17.56-2OB with the 150L fridge. On 12V it is rated at 15Amps. I used to run it from the Aux battery in my old Prado through the Anderson plug. Since upgrading the car (and not yet done the wiring ... slack!) we have not powered the fridge through 12V. We have traveled over three hours and not needed to as it was running on 240V previously to get it down to temp. Stayed cold till we got to 240V access again. The fridges work really well on gas though!!! I am pretty passionate about my beer temp, so I watch my fridge like a hawk!!!

 

[Izzya123]

Thanks @Izzya123 Did you go with that setup to avoid having to swap over to gas when you stop and so you didn't have to worry about accidentally flattening your car battery?
If I don't have your setup, is the car able to charge the normal car battery and power the fridge as we are driving along? I don't know much about electronics, is the alternator able to cope with the extra load?

All great advice..... The gas option when stopping is the easiest...just make sure you have some in the bottle . We did a 3 month trip around western loop of Oz & run a Waeco fridge off the Aux battery in back of tug as well. The fridges run off the aux battery when stopped. They will run down so I change to gas in van for long stops. It's all isolated from car battery so I never have to worry about retuning to a flat car battery.

 

[AddItUp]

Thanks very much @Hubble80 We will probably try something like your approach initially and see how we go. For any long stops, we'll switch over to gas. So long as the fridge stays cold enough for the beer!

 

[AddItUp]

Sounds good @Izzya123 We'll definitely go with the gas option when we stop. Thanks for the advice.

 

[Bmhdg76]

Hi @AddItUp , we just got back from our shakedown trip with our van.
We were also new to the 3-way fridges as I have only ever had the Engel chest fridges. The 3-way works brilliantly on gas as everyone has said. We changed our wiring over to have the fridge draw from the van battery through a Projecta Low Voltage Disconnect. I set the cut out at 12v and found that it generally reached this level at about 3 hours of driving. Our drifter showed that even with the alternator charging the van battery via an Anderson plug at the same time, the drifter showed a net usage of 10-12amps per hour.

Even though the fridge did cut out due to the LVD, we found the temp stayed pretty good - even when we drove for nearly 7.5 hours. We just turned the gas on during rest breaks and as soon as we pulled up for the night.

In saying all this though, I want to see if I can do anything to have nil power usage when running the fridge as would of thought the Hilux's alternator would have been more than adequate. Bit more research will be coming up i think.
BJ

 

[DRW]

depends on the year model of the Hilux, apparently newer ones as well as some other vehicles the alternator all but shuts down on long drives to conserve fuel, they can drop down to 12,5volts apparently as does the jeep. 3 way fridges also draw very hi current on 12V a bit of a pain actually but thats what we have and I disconnest the 12 pin plug when ever I stop, I know I will get caught sooner than later. One day I will get off my backside and do something about it, probably after a flat battery or two lol