ARB Fridge question - Is it running too long?

[4x4mike]

I've recently picked up a 50 qt. ARB fridge/freezer and have been experimenting with it. Trying to figure out it's power consumption and what temperature to keep things at. I had a system down for 3-5 days using an traditional ice chest but realize this fridge is a different ball game. This unit will live in the back of my 4Runner and I'm thinking it will be plugged into the vehicle 12v port while moving. I also have a solar generator I can use and will most likely plug it into that while stationary. The 4Runner has a single battery and stock electrics. The primary solar generator is a 22ah AGM unit with an MPPT controller and 60w panel. I have another solar generator with a 100ah AGM battery and 100w panel but would like to keep that at home because of space. For testing I'm using a combination of all of the above and AC power.

I'll boil it down to my question. Last night the compressor ran for 3 hours and it just seems like that was too long. The draw started at ~5 amps, settled at 4.5 then hovered at 4.1 for about 2 hours. That draw for that amount of time puts quite a strain on a battery and with an AGM the voltage drops while the compressor is on. The fridge was indoors (~75*) and I had it set at 24*. It was half filled with drinks and some assorted other items. The sun was down and the battery went from 12.6v down to 12.2v during the run. Is three hours what I should expect for this to run with these operating parameters? If the sun was out my system would support such a run time but again, three hours just seems so long. I was thinking it would run more often for shorter amounts of time. FWIW my temperature gauge is accurate and calibrated.

Now to some reality. I have no idea what temperature my old ice chest kept my drinks at. As days increased the temperature also increased but my stuff was always cold. My home fridge, after some measuring, keeps my drinks (for example) at 36* and my popsicles at 6* (F). Knowing this I'm thinking it's unnecessary to have my ARB set at 24* for non freezer items. Who knows how long it would run if I had it set to 10*? Today I have it set at 30* with hopes that it will run for shorter periods of time and keep my drinks at a desirable temperature without putting a strain on my battery or the need to carry around a much larger battery.

For fear of asking the same questions others have asked, I have a few additional questions. What do you keep your fridge at if you were using it as a freezer, say for ice cream or popsicles? Does it run for very long times trying to keep it that cold (say 60-70* temperature differential)?

 

[proper4wd]

It being half full is part of the problem. Was the stuff you put in it pre-chilled or was it all ambient temp? Based on your description Im guessing you loaded it up with ambient temp drinks and the fridge had to work for a few hours to cool down the mass to a stable temp.

 

[Stumpalump]

It's nothing like your home fridge with thick insulation and a fan to circulate air. You have a small cooler with a metal ring around part of the inside that gets cold. The sensor to detect how cold is in the middle of the plastic non cooled bottom. If you fill the cooler with water bottles and set it to 34 then the bottles against the cold metal will freeze before the ones in the middle and the sensor reach 34. Plugging it in at the house with it filled for two days helps stabilize it dramatically. It's a must do. When solar is on of if I'll be driving I set it for 32. At night I bump it to 40 and it hardly runs. For your use as a deep freezer then you need a second battery and the wire kit to wire it directly to the battery unless you monitor it constantly. It will shut off when the batt gets a little low and yes it's going to run hard at 20 degrees. Leave a little airspace around the vent to let the heat escape. I love mine.

 

[ducktapeguy]

Were the contents already frozen when you put it into the fridge? Freezing liquids takes a LOT of energy, a lot more than cooling or maintaining a set temperature. So if your contents weren't always frozen, the fridge is going to be working continuously just to get them to the set temperature. Once everything is frozen, then the power draw will drop dramatically. If I fill my fridge with water bottles, it'll take a day or two running continuously before everything gets frozen and the compressor starts cycling.

I'll usually pre-freeze everything before loading it into my fridge, then set the temp to around 34 degrees. Since it's very close to freezing, the frozen items stay frozen but it requires a lot less energy to maintain that temp.

 

[Bbasso]

Please rephrase "solar generator" to solar system.
Because you're not making solar, you are harvesting .

 

[67cj5]

I set mine to -5*c and then added a load of frozen food and it never switched back on until 481 minutes / 8 hours 1 minute later, LOL


Now that's what I call a Low Battery Drain, lol. the most mine has ever stayed on for is 21 minutes 6 seconds, but depending where the Temp is set it normally comes ON for about 9 to 11 minutes when set to 4*c and it stays off for about 1 hour 30 minutes to 1 hour 40 minutes+, AND at -5*c it varies between 11 minutes and 15 minutes +/-

hope that helps,

John.

 

[krick3tt]

I plug mine into house voltage the night before and load up in the AM with cold items from the house fridge. I keep it at 37 deg while traveling and every thing is good for many days or as long as I am traveling, even in the desert temps of 100+ it hardly varies. I run the ARB from an aux battery so the starter battery is never under any chance of not starting the vehicle. Haven't kept track of how long it runs at a cycle but with the aux battery it is not an issue.
It is in the center between the second seats in the LR and at night the top is used as part of my sleeping platform under the pad. It rarely runs in the cool of the evening.
Thinking of getting an official insulation blanket for it.

 

[67cj5]

Depending on the temp setting they will come on for about 13 minutes and off for around 50 minutes when set to -9*c / 15.8*f and when set to 4*c / 39.2*f it will come on for about 10 to 11 and a half minutes and stay off for 1 hour 32 minutes to 1 hour 40 minutes.

John.

 

[4x4mike]

Thanks for all of input guys. I'll try to answer some of the questions raised above.

For one I'm not trying to freeze anything or really to keep things frozen. I believe this will take too much energy. For the most part I want to run at temperatures that are similar to my home fridge for taste/enjoyability but also food safety. My home fridge keeps my drinks at 40* (trying to remember off the top of my head). After a couple days of testing the ARB this seems to require the ARB to be set at about 28*. I'm trying to look past the actual number and am thinking of it as more of a setting. While at that temp my drinks are cool and the fridge doesn't kick on for many hours at a time, like 10 hours. Buuuttt, when it does kick on it's rocking for a long time.

Long time being 2-3 hours with a majority of that time below the set temperature. So, if I have the screen set to 28*, it kicks on at 29* or 30* and within say 20 minutes it's back at 28* but then within an hour it's at 26* and will stay there until I up the temp. During that time my solar controller reports draw from about 3.5 to 5 amps.

Question: When does your fridge kick off? Once it reaches your set temp? One degree below? Two degrees?

Maybe my 28* setting is too low and it's taking too long to get to the kick off temp? I'd like to know the built in parameters of that kick off feature and make sure mine is running correctly. Perhaps if I upped the setting to 30* it would reach the kick off temp in a shorter time and still leave the food at an acceptable temperature?

I understand where the temp is being taken and how airflow and contents affect the overall temperature inside of the fridge. For the most part I've got it loaded as I would on a trip and am testing it as such. In reality I'm opening it far less. It's more real world than ideal but way within 'normal'. I've got a Victron MPPT that records input and load and I've been downloading the results when I get home from work. I'll check them out tonight and compare to previous days.

I guess if I require it to be at a certain temp I'll make sure I have it receiving vehicle power while moving and/or while the panel is 'harvesting' full sun. That way the battery from the 'solar system' can maintain the fridge at night.

 

[67cj5]

Ok, lets start from the beginning due to being from the land down under I talk in *c So this is what happens with 99% of all fridge freezers, If/When I set my 47L IE 4*c if it has been closed it will turn it's self On at around 5*c or just before it changes to 6*c, Now that will stay on until it is on the verge of changing to 3*c, Then it shuts off and as it sits there the temp will do it's thing and within the first 15 to 20 minutes the fridge Dial will drop to as low as -3*c until the gases settle and then cold evens it's self out in the fridge and the temp reading stabilizes with the numbers slowly coming back to the temp you have set it too.



If you are setting your ARB to 28*f / -2.22*c then it sounds like you need to Calibrate your Dial/Buttons because at -2.2*c you should have beer cans bulging or lids popping off bottles so that tells me your fridge is reading roughly at about 7 to 9*f too Low OR roughly 5*c to low, DON'T WORRY because you can correct this at the push of a button. Many people complain that the Setting/Dial is not accurate but this can be because of two reasons One it is not set right from the factory which you can fix with the buttons and TWO there is no fan inside pushing the Air about to even the Temp so depending on where you place a thermometer inside you will get different reading, So I suspended one thermometer almost at the top of the basket divider and another in the bottom, The one in the bottom will read the coldest but the one on the divider will read the closest, I also used a Laser thermometer to take readings from at leased 12 other areas within the fridge and my one is actually spot on, Anyways lets worry about yours, and because yours is reading lower you need to add numbers OK, because like the person in the text his is doing the same as yours anyway. I just stole this info from another forum so forgive me, My Bad. but it goes like this. QUOTE:-
1) Press and hold BOTH + and - temp setting buttons and HOLD for about 5 secs until AOF appears on the display, then release
2) Using the + or - button, add or remove degrees to the setting. For me I was running warmer so I added (+) degrees to the reading to match the internal temp.
3) After adding degrees, release the button and the fridge will blink to acknowledge/accept the new setting and begin to adjust accordingly END QUOTE. I hope this helps and remember despite that your fridge is "NOW" reading 28*f on the Dial the fridge might be thinking that it is correct so it will stay on for longer when in fact the true temp is a fair bit warmer so that is why it could be staying on longer than it should, sounds silly but heaven knows how the software works but it makes sense to me. Anyways give that a go and see how you get on, but remember to take every thing out of your fridge and Hang the thermometer from the basket divider and if it is the long type of thermometer then wire it in place sideways so the bulb is not in the bottom where it is the coldest, Ok..

Good Luck.

John.

 

[vladig]

To help with air circulation in my 50qt I purchased a battery powered fan used in RV 3way fridges ( http://a.co/1i3qjVU ) and this seems to help tremendously in circulating cold air from the bottom and pushing the air up to the top