My ARB fridge endurance experiment

[gumboot Avid PP Poster! Find all posts View Profile Close gumboot]

Hi,
I ran my littte fridge experiment over the last coupe of days. Here were the results you may be interested in.
I have an ARB dual battery setup. The auxilary battery in an Exide ED50 deep cycle 65AH,(cant put bigger as it is a rear engine bay ARB mounted battery) with a surepower isolater.
The Frige is a ARB 47 litre and the battery saver option was set to low ( 10.1Volts as per ARB recomendation with a dual battery) . I set the fridge to 4 degress and left it empty, and did not start the car or charge the Aux battery during the experiment.
All measurements were taken at the aux battery with a multimeter.

9am Day 1- Turned the frige on.
Main battery 12.60 volts
Aux battery 12.63 volts

9pm Day 1
Aux battery 12.41 volts

9am Day 2
Aux battery 12.29 volts

9pm Day 2
Aux battery 12.07 volts

9am Day 3
Aux battery 11.42 volts (Main battery still 12.60 volts)

Thought this may be of interest to some
cheers

[Strahan Advanced Member Find all posts View Profile Close Strahan]

Do you know how much the compressor ran for? Hot days or cool?
Good results though.

[gumboot Avid PP Poster! Find all posts View Profile Close gumboot]

Do you know how much the compressor ran for? Hot days or cool?
Good results though.

Good point. The two days were about 29 degress both days and about 24 degress at night.
I wasn't watching the compressor that much but when I did look every now and then , it was cycling on and off at various times. On the arb fride, it is green when the comressor is running and orange when it is not.

Cheers

[Madkore Avid PP Poster! Find all posts View Profile Close Madkore]

Well be interested to see how many days you get gumboot. I'm thinking of getting an ARB Fridge later in the year.

I also wondered if the results would change if you had items in the fridge.

[Shan Senior Member Find all posts View Profile Close Shan]

I also wondered if the results would change if you had items in the fridge.

I reckon it will run longer full !!! Interesting to see how long can you get out of it gumboot....

[maxjj Senior Member Find all posts View Profile Close maxjj]

interesting test, but I am kind of thinking its a bit meaningless.

This thread raises a few questions. All you have measured is how much much heat is leaked into the fridge while its mounted in a car and that some amp hours from the battery have been used to remove it. I would not think having thermal mass would be relevant, once its all cold, as long as you don`t open or close the door as there would be an exchange of hot air and cold air every time you opened the door, a full fridge would have less air to exchange.

12.6 V is 95% full charged battery down to 11.4 V approximately 15 %--- 80% of 65ah approximately 52AH have been used.
17 a/h per day or in 24hours.

11.4 V a bit low for my comfort zone, that may well damage your battery in the long term.


I have a 12 year old 40ltr Fridge/Freezer Waeco, bought it when they first appeared on the scene, I roughly use the old 25a/h a day as a guide, but that includes using it as a fridge, with taking stuff in and out and in a closed car. Typically I take out a cold stubby and put a warm one in. I have survived plenty of Friday am to Monday am weekends with a 100A/H battery.

But then I once put a warm slap of stubbies in the fridge one night and the next day was a 40 degree day, wife drove the car 20 Km to work and parked in the full sun and drove home that night, by the end of the following day, also a hot day, the battery was flat. Beer was cold though.

I think the most important part of any fridge of battery system is how quick you can get the a/h back in the battery. Typically you park a few days with a short drives to explore, the critical part is always getting as many amp hours back in the battery as quick as possible. ie two 20km drives of about 20 minutes each was not enough once your system is worked hard and battery volts are down.

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

I posted in another thread about the results I logged from my NL fridge/freezer and it averaged about 17Ah per day but that was mostly full of food and in temperatures ranging from mid 20s to mid 30s and no sun protection other than the solar panel on the roofrack. Since then I have left the monitor on and kept an eye on the data being logged. Daily consumption is higher with an empty fridge because air doesn't have much thermal mass. I have set my low voltage cutout to 11.5V and over the Christmas holidays (no solar panel) the car doesn't do the usual trips and the auxiliary charge falls to minimum over a week or so with such little usage.

The main observation for me was that my 100W solar panel pretty much keeps up with the consumption of the fridge when we are camping so any running of the motor from trips up and down the beach is a bonus.

[Gday Bruce Lurker Find all posts View Profile Close Gday Bruce]

Fridge Experiment - Try Techni-Ice

I run a 35Litre Waeco 7 days a week from an ARB dual battery system (possibly 50AH).
Expected return-trip (charging) time is 70-90 mins, 7 days/week.
Based in Sydney, & parking without shelter, outside temperature up to 32c (car interior estmated @48+c) when we're not experienceing our current Melbourne sourced rain.

Fridge regularly containes between 4-12 stubbies, and on the low battery setting was originally unable to cope to our (me & the boys) satisfaction. (I developed the habit to switch to low @7:00am each morning, & back to high after lunch)

I initially included 1 to 2 plastic frozen 1.25 litre water bottles (replaced every second day) to assist with retention of core temperature. I've since discovered a great product called Techni-Ice (to which I have no connection), & purchased an ABR Fridge Moniter.

Experience over last 3 weeks with 3 sheets of (24 cube) Techni-Ice (replaced every 3 days) is Car/Fridge approx. Max. 48c/13.7c, approx. Min 16c/-3c (overnight). (A cold beer over lunch if you don't have to drive, is something worth killing for.)

Techni-Ice can easily be found on a Google search. (I'm a satisfied customer, not a shareholder).

IMO it's a product well worth checking out and over the long term will save on ice, & the pain of esky puddles . As longas you have access to freezer space every few days.

[Rodders Junior Member Find all posts View Profile Close Rodders]

Just on the Techni-Ice, I bought one of their 70l eskis that came with 1/2 dozen sheets of the Techni-Ice, it is good if you don't have to keep opening the eski - common sense really I suppose. I quickly found that using in a normal camping environment the techni-ice would be done in less than 24 hours. In comparison with regular ice in the same eski you could have ice in there for probably 48 hours in that same camping environment. At a BBQ we had a while back we just used it for the beer, but opening it fora beer at regular intervals was enough to have it back to useless gel in a few hours - and the beer getting warm, where as in the same scenario there is normally still a few bits of ice in the water the following morning, ad the beer is at least chilled. If on the other hand you filled the eski pretty well and left it closed, you could probably get a couple of days out of the techni-ice, I did a test just after we got it and it made it to 36 hours just in an empty eski that was only open once or twice. According to their advertising the sheet supposedly freeze to minus 18 or so, but I think the problem is that that means they absorb any heat pretty quick - if my school science memory serves me correctly. The other thing I have found with the techni-ice is that it doesn't make things cold like ice does, I think because it doesn't have the same contact surface area that the ice does. The short term bonus about the techni-ice is that unlike ice it doesn't make stuff wet, although the sheets are a tad slimy.

Just my 2c on techni-ice.

Cheers
Rod

[4wd Supplies Member Find all posts View Profile Close 4wd Supplies]

Interesting test there mate, I have the same fridge and really rate them. I have run it for 5 days straight on a 120ah battery and it still had plenty left.

[Gday Bruce Lurker Find all posts View Profile Close Gday Bruce]

Rodders,

Thanks for & appreciate your 2c's worth.

I had neglected to mention that in an esky situation where chill is the key (as long as you can drain the puddle), nothing beats ice.

My point with the Techni-Ice was about retaining core temperature while limiting battery drain.

Bruce