Used 12V RV fridge test

[Bella PSD]

I just picked up a koolatron used RV Fridge for $10. It looks just like a RV built in fridge. I would guess this came out of a pop up camper?? About 55 quarts big. Thermoelectric, of course. That’s the best way I can describe it. Looking for the model #?? Nothing on line about this fridge at all(Google search).

I know the Thermoelectric’s are not recommended. But I thought for $10 and the fact that it’s 55 quarts, why not. Only $10 to loose.
And maybe because it was made for a built in RV installation, maybe it will perform better???

I temporarily hooked it up today in the Flip Pac and it seems to work well.

So far, here is how it doing.
6:45pm turned on at 79 degrees ambient
7:45pm 49.5 degrees 74 degrees ambient
8:45pm forgot to check
9:15pm 39.5 degrees 70 degrees ambient
10pm 34.5 degrees 68 degrees ambient
10:30pm 28.1 degrees 67 degrees ambient (below freezing !!)

10:31pm Turned the thermostat down until the unit powered down.
I think this would be a 6 setting out of 10 on the dial, 10 being the coldest. Its now 3am and it has kept a steady 31.9 degrees for 4.5 hours. So far this Koolatron fridge DOES out perform my Absorption Domtec fridge on AC power power!

I am going to let it run till the battery dies. We’ll see if it’s days or hours?? Total run time so far, 8 hours. Keep in mind the fridge is empty, so this will not help. But I am trying for a worst-case test. If it makes it to see sunrise, I will roll the camper out in the sun with the windows shut. Reporting back after I get some sleep…IT’S 3AM:coffeedrink:

Louie

 

[Bella PSD]

10:30am 31.4 degrees. still holding good.
1:30pm battery was down to 4.8 volts and temp was 39 degrees.
hmmmm. Now that I think about it, the battery was probable not fully charged last night when I started. It has been sitting since Nov. unused.

I try again with a fully charged battery!

 

[davegonz]

Are you sure that's a thermoelectric?

 

[adventureduo]

Seems to be working really dang good for $10.00!

 

[Bella PSD]

Are you sure that's a thermoelectric?

No, but I can pick it up with 2 fingers. It must be all of 10 pounds. It must be thermoelectric. Thats all Koolatron made, right??

 

[Bella PSD]

Seems to be working really dang good for $10.00!

Yes it does seem to be cooling real well. But if it kills the battery after 1 day, I am not sure if it going to work out for me. Surprised that when the battery dropped to 4.8 volts the fridge was still holding on and trying to cool. Maybe it is built to a higher RV standard and that’s why it seems to cool so well?? I never thought it would hit sub freezing so quick from a hot empty fridge!

I will start the test over in the morning with a fresh charged battery.

I just found B-42 on the side of it. I quick goggle search turned up nothing but an old picture of it.

 

[astn]

I'm no expert by far, but with that radiator on the roof of the interior, I would say with some certainty that is thermoelectric. Any final word on how long it held up?

Austin

 

[Bella PSD]

Yea it's thermoelectric, Starting the test over again right now. Fresh battery, camper in hot sun and starting it out with a full load of water bottles that are hot from sitting in a van all day. That should be about as bad as I can think I would ever have it??

 

[evldave]

Water bottles works as a test, here might be a better real-world test:

• Fill with warm 12 oz beer cans
• Every 30-45 minutes, open fridge and remove 2 cans
• After removing most of the cans, fill back up with warm cans
• Forget to fully close door after refilling
• 30 minutes later, open fridge, remove 2 cans, realize you left it open last time and close it tight this time
• Repeat

idk about you, but this would pretty much simulate all uses I would have for a camping fridge!

 

[Bella PSD]

New test!!

How ironic, new test showdown starts at high noon!

Sunny and 71 degrees ambient. Loaded up the fridge, that’s about 55 quarts big, with (28) 16 oz luke warm water bottles.

To start out, the fridge quickly rose from ambient (70) to almost 80 degrees because of the warm water bottles.

Battery was slow smart charge at 2amp’s the night before. Test starts out with battery volts at 12.5. Battery details coming soon. It covered up in the camper and hard to get to. But it’s just a deep cycle battery from Sam’s club. One year old and only full drained two times within that year.

With this being a thermoelectric fridge, this may be a total waste of time. Time will tell. I’ll post back later with how it’s doing.

evldave, I will add opening and closing to the test after it hits a set temp, say 37 degrees. Thanks!!

Louie

 

[teotwaki]

From the test numbers:

7:45pm 49.5 degrees 74 degrees ambient -----------> 24.5 degree delta from ambient
9:15pm 39.5 degrees 70 degrees ambient -----------> 30.5 degree delta from ambient
10pm 34.5 degrees 68 degrees ambient -----------> 33.5 degree delta from ambient
10:30pm 28.1 degrees 67 degrees ambient (below freezing !!) -----------> 38.9.5 degree delta from ambient

Looks like a thermoelectric........

It would be nice to measure the amps that it is pulling.

 

[BigAl]

Water bottles works as a test, here might be a better real-world test:

• Fill with warm 12 oz beer cans
• Every 30-45 minutes, open fridge and remove 2 cans
• After removing most of the cans, fill back up with warm cans
• Forget to fully close door after refilling
• 30 minutes later, open fridge, remove 2 cans, realize you left it open last time and close it tight this time
• Repeat

idk about you, but this would pretty much simulate all uses I would have for a camping fridge!

Protocol amendment:
<Every 30-45 minutes, open fridge remove 2 cans and drink>
Repeat until the beer is gone, if the last beer is warm, you won't care:birthday.sml:

 

[Bella PSD]

It would be nice to measure the amps that it is pulling.

It is pulling 3.5 amps. I measured this in line from the battery to the fridge on the positive lead. Multimeter set to read amps up to 10.

All the battery say is 875 amps. So does that mean 3.5 amps into total amps available (875)?? That would be 250 hours or 10.4 days. That can’t be right!! The amps must drop of at a faster rate as the volts drop???

Louie

 

[teotwaki]

It is pulling 3.5 amps. I measured this in line from the battery to the fridge on the positive lead. Multimeter set to read amps up to 10.

All the battery say is 875 amps. So does that mean 3.5 amps into total amps available (875)?? That would be 250 hours or 10.4 days. That can’t be right!! The amps must drop of at a faster rate as the volts drop???

Louie

875 may be the cold cranking amps? You'd want the amp-hour rating off of the battery for the calculation of duration. Probably more like 70 Amp-hours so divide by 3.5 to get 20 hours of running time. A draw of 3.5 Amps is higher than an Engel's 2.5 Amps.

 

[peekay]

also, you can't really discharge the battery down to zero amps. In reality, your battery has between 70-115 amp hours, of which approximately 50% or so are useful. So in essence, you have between 35-57.5 amp hours. That gives you about 10-18 hours or so before your battery should be recharged. 3.5 amps isn't too bad, you can get a solar panel that will replenish a large portion of that.