Actual Fridge Power Draws

[67cj5]

When my Indel B 50 was new and when my house batteries were new, that fridge would hold -22C when outside ambient touched 128F in mid-afternoon. Fridge had been pre-chilled, some of the stuff went in frozen, fridge was near full, had a pile of clothing (insulation) on top of the fridge, factory window tint, white truck, etc. That was a huge drain on the batteries, but it worked as long as we moved around a couple times per day, usually 70-100 miles per day on a 270amp alternator. Stay parked and the batteries were done in maybe 18 hours. Interior cabin temps would go north of 185F, so delta was about 193F. My ARB 50 can't do that, even though it's new.

ARB states in the manual that their fridges will go 122*f below the ambient temperature, You are lucky to be alive, because running a fridge in those temps is a crazy thing to do, the standard pressure for that type of fridge gas would be multiplied by at leased 12 times and not only that it would cause your fridge to leak meaning that if it was better when it was new then the damage has already been done,

If a fridge is going to be run in those type of temperatures then it needs another type of Gas inside it, because the fridge gas r134a is not meant to be used in such high temperatures.

 

[Ducky's Dad]

If a fridge is going to be run in those type of temperatures then it needs another type of Gas inside it, because the fridge gas r134a is not meant to be used in such high temperatures.

Well, maybe. But I doubt that Arizona is hotter than parts of Australia or South Africa, and these were designed for those conditions. The fan in my Indel B died after about three years of light use in hot conditions so I had it repaired by a local yacht electronics shop that does a lot of fridges. They told me pressures were fine and the problems were electronic rather than mechanical. New fan seemed to cure the problem. We'll see what summer brings.

 

[67cj5]

Well DD, fingers crossed it all works out for ya,

I have come up with a new plan of attack and that is to get my roof on the truck covered in a reflective material and also tint the windows with mirror type tinting and hopefully the combination of the two will help it,

In the conditions you describe just about any fridge is going to have a job on it's hands, As a side note there are about 8 or 10 different Gases out there to cope with many different temperature ranges so maybe that might be another option for you, ??

Stay safe,

 

[Ducky's Dad]

I fooled around with different gasses years ago because the AC in another truck just wasn't cooling effectively. It is a 134 system in a GMC and I found some propane-based refrigerant from Canada that worked very well. Only problem was that the AC squeaked constantly with that stuff in it, even with added lubricant. Used it for a couple of months but then evacuated it because we thought it might be damaging the system.

 

[67cj5]

I fooled around with different gasses years ago because the AC in another truck just wasn't cooling effectively. It is a 134 system in a GMC and I found some propane-based refrigerant from Canada that worked very well. Only problem was that the AC squeaked constantly with that stuff in it, even with added lubricant. Used it for a couple of months but then evacuated it because we thought it might be damaging the system.

Yeah DD, I guess a person needs a fridge that is Gassed up to suit their part of the world, ARB was tested and built around their findings out in the Aussie bush and they do work well, Having grown up in Aus and worked out in the Bush the weather out there can be quite brutal, So if fridges and trucks etc are not up to it then it is a good place to test them out,

My facts and figure are from using a stock fridge but even in constant temps I can get about 3 or 4 different Duty Cycles all related to how you pack them, Add to that Ambient temp changes etc and a standard set of figures can vary so much, In the same temps as I did the other 2 tests my Max cold test didn't work out because I left the food in the plastic packaging with huge Air gaps in sealed packs, So now I have removed the packaging things have settled down I have to start again, I think I am going to do the tests in 2c steps because then I can work out which setting gives the best power/cooling and a reasonable run time, So far 10c works good for keeping things frozen for short term outings up to a month +/- where you still can use the top Area above the element and the dairy section as a fridge, The lower area in the main compartment can drop to as low as -12 to -13c as the cold Air sinks down which is a good thing when set to -10c,

 

[billiebob]

One of the easiest ways to reduce power use is to keep the fridge full and load it only with refridgerated items.
Never leave something out for hours and put it back in warm.
If the fridge is full it does not matter how often you open the door.

 

[1Louder]

Here's an article I wrote a couple of years ago. All indoor testing so your mileage may vary. I tested 4 different brands.

https://www.4xoverlandadventures.com/2017-winter-fridge-shootout/

 

[67cj5]

Here's an article I wrote a couple of years ago. All indoor testing so your mileage may vary. I tested 4 different brands.

https://www.4xoverlandadventures.com/2017-winter-fridge-shootout/

That's a great thread, Well done for taking the time to do it, I found that a while ago and saved it to my favourites, hope you don't mind, But your figures seem to match mine +/- which is a good thing because I was quite surprized when I got figures even lower than what ARB claim and their figures are impressive to say the leased but my figures ended up being less than half of what they claim,

As you can see I have been getting Average readings of 0.398Ah and lower and higher up to 0.405Ah, So far I have tested my ARB 47L at 4c , and -10c, but I will have to retest the -18c again because I packed the ARB a 1/3 full of packaging with big Air spaces in them, But at the moment I am in the middle of testing it at -12c only packed correctly this time and I am getting 75 + minute Duty cycles but no doubt they will get longer which is good from the batteries point of view, The 4*c was very impressive and the battery run time was way more than I expected, If I had set the battery protection mode to MED or Low then I could of gotten 8 or 9 days out of the battery but common sense told me not to risk damaging the battery,

Thanks again for your input, that's a great article.

 

[Ducky's Dad]

My ARB is sitting on the kitchen floor running on AC. It is full of meat and has not been opened in two weeks until just now. The ARB display shows -18C, but my infrared thermometer shows -16C to -12C in the main compartment, depending on where I measure. It is probably -18C at the bottom, but I didn't unpack to check the bottom. I actually prefer the performance of the Indel B (which is back in the truck), but the ARB seems to have better build quality.

 

[67cj5]

My ARB is sitting on the kitchen floor running on AC. It is full of meat and has not been opened in two weeks until just now. The ARB display shows -18C, but my infrared thermometer shows -16C to -12C in the main compartment, depending on where I measure. It is probably -18C at the bottom, but I didn't unpack to check the bottom. I actually prefer the performance of the Indel B (which is back in the truck), but the ARB seems to have better build quality.

I think you will find that in the bottom of your ARB it will be about -21.4 to -21.5 ish, you can't use a laser in them because a laser under reads the temp on white or silver surfaces, I use a digital thermometer that reads the inside and the outside temps,

with the sensor wired to the top of the divider I get a matching read as to what the ARB is set to and then it will go 2 or 3 degrees lower within the first few minutes of it switching off and then it will start to rise slowly, In the bottom the temp is always colder because as you know the cold air sinks to the bottom and if you put the sensor between the walls of the ARB and the basket you will see the temps really drop down to around -28*c,

If your meat has been in there that long if you pick up a lump of it it will actually make you hand ache if it does that then you can be sure it is a lot colder than -18c, These fridges will warm up by 1c and cool down to the exact temp setting and then they will drop a couple of degrees lower and then rise again, The Temp sensor in the bottom of the fridge is a lot more stable than using an after market thermometer because if it fitted within the base of the unit where as an after market sensor will pick up every little change, they are good if you want to map out what the fridge is doing but too erratic for proper measuring because of their sensitivity,

Another thing with these ARB fridges is that they get so cold inside that chunks of meat become Rock Solid and as hard as granite unlike domestic fridges. They way out perform domestic fridge freezers, Having tested domestic freezers even small ones their temps can vary from 9c to around 17.8c, Fan forced freezers sound like a good Idea but they stop you from being able of using them as a Duel zone where as fridges like the ARB's you can set them up to perfection with a bit of effort and know how. In the beginning I wanted an Engel but I am so glad I went with the ARB's because they do so much more and have a heap of features that lend them selves to everyday living although they were made as a true 4x4 fridge.

I like the Snomaster range but because my needs vary from week to week ARB are just streets ahead.