I have been looking for a previous topic that covered my dilemma, but to no avail.
We have purchased a 5 yr old van with the standard 2 door 3 way Dometic refrigerator.
Everything's good - except the 12 v wiring to the car. The people that installed the reversing camera/bluetooth/USB/radio etc. in the car, also put an Anderson Plug in for the fridge, but through a stuff up in the 'vans wiring, the fridge never worked on 12 volt and kept blowing 40 amp fuses.
Found a Auto elec. (who owns a 'van) and he found the fault, but has now wired the Anderson plug to charge the batteries, not the fridge as he says I will need a lot heavier cable to run both and wants to put another A. plug on just for it.
The wire running from the batteries to the A. plug is 6mm auto cable and the wire running from the tow bar to the fridge is smaller again.
Our car is a 100 series 4.2 diesel Land Cruiser wagon which has 2 batteries both connected as start bank and, I believe, a 140 amp alternator.
Want I want to know is, as I now have 250 amp/hrs of AGM batteries with 310 watts of solar with a 40 amp mppt regulator which is also being charged by the vehicle, can I wire the fridge to the house bank while travelling? We always change over to gas when we stop for any time, and there is a remote station in the galley showing battery information should we have a senior moment and not turn it over for a while.
The batteries are now mounted under the dinette opposite the fridge, so the length of cable will be a lot less than any other way, and I have heavy cables left over from moving the battery from the front boot. Can't remember the size but the cost was $13.00 mtr. if that is an indication of size.
I have been told so much stuff by a few elec's, but I can't see a reason why this way can not work.
If I am reading that correctly you want to run your 3 way fridge on 12v from the vans batteries while travelling.
Mmmmm, thinking about that I don't see a lot of difference as running it off the tug while travelling however, 3 ways are not designed to run of your van or tug batteries for any great length of time while stationary, i.e. camped. For one thing, at least your tug battery won't go flat while at lunch or shopping etc.
Now, I have as your auto elec suggested, 2 Anderson plugs, 1 for charging the van batteries and 1 for running the fringe. I have 6B&S cable to both tug Anderson's and van batteries but 6mm to fridge. Both have in-line fuses near tug battery. All works great and I am more than happy with it. All very easy to do yourself.
I must admit, I have thought of connecting fridge to van batteries while travelling though. So will sit on the bench now and see what happens.
Keep Safe on the roads.
-- Edited by Dougwe on Friday 29th of January 2016 02:25:49 PM
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Wouldn't run anything off the tug battery while stationary unless you have a dual battery system & isolation switch in your tug like we have. At least if your tug battery goes flat you have another one to start your vehicle & you won't get stranded out in the bush. What's wrong with running your vans 3 way fridge on gas when you're camped? A 4kg bottle lasts us 9 days, we have 2 bottles. Fill up at BCF, cheap as chips.
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My condor van has the fridge running off the van batteries
Anderson plug from dual battery charges van batteries when moving, solar charges batteries, and 240v charges when on power
It all seems to be working well
Ken
I am not tech minded but our Dometic 2350 3 way fridge in our Mercedes Sprinter Campervan is connected to one of the house batteries (80ah) which is connected through a VSR to truck battery (Alternator) & works excellently whilst underway. My understanding is the VSR disconnects the truck battery when the engine is off & its voltage drops below 12.8v & we always run the fridge on gas when camped up as it draws 175w on 12v. The house battery has always remained fully charged whilst travelling with the fridge on & that battery is approx 5 years old but the only other things it runs is interior lights & phone/laptop charging as we have another 200ah house battery for TV, Video, Rangehood water pump etc.
Hi, I have just set up 2 anderson on my tow vehicle, one for fridge one for house battery,
The house battery anderson comes of my backup Battery under the bonnet which has a dc dc redarc 20amp charger
The Fridge anderson comes from my starter Battery however it goes through a isolator that disconnects as
soon as the voltage drops below 12.8 volts, (Isolator from Jaycar)
I have kept these separate as the fridge draws 21amps.
I guess there are many ways of connecting your fridge however you must have a system to shut it down as soon as the
engine is off
If you connect to the house Battery you will run them down in no time if you forget while setting up
our Dometic 185 lt 3 way fridge/freezer runs off the house batteries when we are travelling. The house batteries are charged via the one Anderson plug. We have been stationary for 3-4 hours with the tow motor off (which means the house batteries are not being charged) and there is no noticeable drop in power reserves as shown on the 250amh batteries LED display. But obviously we don't open and close the fridge constantly if only running off the batteries (normally they are charged by solar when tow vehicle is turned off, or by gas or 240v)
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The amazing things you see when nomading Australia
Slowcoach you can run your fridge off the house batteries when travelling. However the 6mm auto wire that the Anderson plug is currently wired (pun intended )with will have so much voltage drop that the house batteries will fail to receive any charge.The fridge draw alone will require about 14-15 Amps to replace what is taken out of your house battery then more still to charge house batteries. So you will still need to replace the Tugs Anderson plug wiring with much heavier cable . Suggested minimum size would be 6 or 4 AWG depending on length of cable run, not forgetting that the earth return needs the same size cabling.
As Alan suggested, a minimum of 6B&S (AWG) and run it all the way from you vehicle battery, through an isolator, to a pair of terminals near your van battery. Then run a minimum or 8B&S pair, via an ignition controlled relay (or fridge switch) from the set of terminals to the fridge, and another another 8B&S pair to the battery (or battery charging system if you have one). And Fuse all cables at the battery connections.
Edit: I forgot to say, having the 3 way fridge permanently connected to the batteries (ie not through a fridge switch or ign controlled relay) will flatten you batteries very quickly.
-- Edited by 03_Troopy on Saturday 30th of January 2016 08:54:29 AM
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John, You did not specify the size of cable through the Anderson plug. Without that knowledge no one should be giving a definitive answer to your problem. Another thing that should raise alarm bells about the answers is when they say "I run my fridge off the vans battery when travelling." When on the road the fridge should be running off the alternator, if the fridge is running off the battery it means that the hot wire is not thick enough. We have had many reports of people who think they had sufficient cable between the alternator and the fridge/battery but the cable was not large enough to supply both the fridge and charge the battery. The result of this is the battery is not being charged but is being discharged whilst it supplies power to the fridge.
That is why many of us recommend separate cable for the fridge and the battery. Going that way is the only method to be sure of getting good charging for your battery. Your auto electrician may have not been certain that the cable was sufficient to supply the fridge and also efficiently charge the battery.
I am not a fan of fridge switches. My preferred method is to use separate feeds for the two services. Fridge switches do go faulty, when they do they are easily bypassed by pulling the plug. Use a separate fridge line with an ignition switched relay for best operation.
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PeterD Nissan Navara D23 diesel auto, Spaceland pop-top Retired radio and electronics technician. NSW Central Coast.
elliemike wrote:My Anderson Plug is wired in from the Tug in 20mm Square twin wire. Then 20mm Square through to the House battery. Never had a problem in 6 years.
I had my wiring put in by The !2 Volt Shop in Kewdale, Perth. At the time they said they would not do the job unless they used 20mm Square Wire.
6 SWG cable is 18.7 mm2 so it's a bit lighter than your cable. This is OK for 1 battery but I would suggest you need 4 or 2 SWG if you have more batteries. More batteries will draw more current when they half flat and to maintain a minimum voltage drop you need heavier cable if you are going to run both fridge and battery charging on the same line.
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PeterD Nissan Navara D23 diesel auto, Spaceland pop-top Retired radio and electronics technician. NSW Central Coast.
Apologies for not replying sooner to all of your posts but was trying to find good 12 volt psychiatrist.
I know (The instruction book tells me) the current draw of the fridge is 3.2kw in 24 hrs/14 amp/hr with no allowance for cycling and I know it will flatten any good unsupported battery in short time.
I will not be running the fridge on batteries when camped. It will run on gas.
Whatever happens, I will not underwire, (made easier by the charts available on the net.) I believe in excess of everything.
Been looking at wire gauges on the net also. What committee came up with them all?
It seems a number of you run the van fridge via house bank charged from solar and the tow vehicle which is what I wanted and I couldn't see a problem with it, but hadn't heard of anyone else doing it that way. Just how I wire it, but that may come.
If my vehicle alternator is going to run all of the electrics in the car, the 60ltr Engel in the back, run the van fridge, and running lights, the house bank will have a holiday and waste the solar input.
I might have to do it myself, if you, Doug, reckon its so easy. I will have an extinguisher handy though!
Thank you all for your input and I hope we meet up one day to compare wires, fridges etc.
These things are worse than boats for "sinking" money into.
Apologies for not replying sooner to all of your posts but was trying to find good 12 volt psychiatrist.
I know (The instruction book tells me) the current draw of the fridge is 3.2kw in 24 hrs/14 amp/hr with no allowance for cycling and I know it will flatten any good unsupported battery in short time.
I will not be running the fridge on batteries when camped. It will run on gas.
Whatever happens, I will not underwire, (made easier by the charts available on the net.) I believe in excess of everything.
Been looking at wire gauges on the net also. What committee came up with them all?
It seems a number of you run the van fridge via house bank charged from solar and the tow vehicle which is what I wanted and I couldn't see a problem with it, but hadn't heard of anyone else doing it that way. Just how I wire it, but that may come.
If my vehicle alternator is going to run all of the electrics in the car, the 60ltr Engel in the back, run the van fridge, and running lights, the house bank will have a holiday and waste the solar input.
I might have to do it myself, if you, Doug, reckon its so easy. I will have an extinguisher handy though!
Thank you all for your input and I hope we meet up one day to compare wires, fridges etc.
These things are worse than boats for "sinking" money into.
John
Different committees a in different places at different times. But being multicultural, we have them all
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