Whynter refrigerator just about killing my battery after 12 hours

[DaveInDenver]

I for one have always thought that "Oh it has a Danfos Compressor"

Something that occurs to me, Danfoss has many different models of compressor and there's always the chance the compressor is a copy or counterfeit. There's not many variations for Sawafuji, just Engel and older ARBs I think, so they tend to be more uniform.

 

[67cj5]

@67cj5, I have noticed that portable fridges benefit from tailoring your use. Being careful to open slowly to not disturb the air, for example. There's nowhere for the air to go once it settles, no seal to leak like a domestic fridge door. I have a transit bag on mine, with the reflective liner, and that seems to also make a significant improvement.

That's right Dave, spot On, they also are sensitive to how you load them, if you pack your fridge with frozen food in those plastic shop freezer packs and fill it up for some reason it takes a lot longer to get the Air temp to balance out inside from the top and the bottom, and also have at leased 3 versions of their on/off duty cycles where they can have a short on time and a shortish off time or you can get a longish on time (About 16 to 18 minutes) and a medium Off time, And a medium On time with a long off time, so folks need to experiment with packing their fridges to see which way works best, because this can have a bigger effect on how much power the fridge uses over a period of time,

I have found that the basket allows a small Air gap that allows the Air to circulate but it is better if you don't put the contents hard up close to the basket leaving about 1/2 inch gap all the way round the edge where the element is and if your fridge basket has a centre divider leave a 1/4 inch gap either side of it so the Air can go through the middle of it's contents that way the Temp at the top will balance out with the temp at the bottom, You hear so many people say that their ARB temp gauge is Off but if you over fill any fridge or block the cooling element from doing it's job you will see differences with any brand of fridge, SO with a bit of thought these fridges can and will work way below the factory Specs,

hope that helps.

 

[67cj5]

Something that occurs to me, Danfoss has many different models of compressor and there's always the chance the compressor is a copy or counterfeit. There's not many variations for Sawafuji, just Engel and older ARBs I think, so they tend to be more uniform.

A lot of these newer MIC fridges use copies of the Danfos compressors so people need to be aware of such companies,

ARB/NL and at one time Dometic Waeco use to use Danfos compressors and all 3 units used the BD35 on it's fridges from 35QT up to 63QT models and the BD50 on the 78L/80QT to 120L models.

 

[john61ct]

They do **not** all use the same compressors, but within the Danfoss **style** that is not the source of significant energy efficiency differences.

The air issue is **very** insignificant, front-opening vs chest style no difference in AH per day consumption, which is the only measure that counts, and easy to get.

The total available volume, insulation and mass of contents loaded is what counts.

And ventilation of hot air away from the condenser and electronics section.

The owner can improve that last, and add insulation with great effect.

Also keep fully loaded, and ideally pre-freeze all possible contents.

Better yet, build a custom box and install a marine kit, but pricey of course.

 

[DaveInDenver]

The air issue is **very** insignificant, front-opening vs chest style no difference in AH per day consumption, which is the only measure that counts, and easy to get.

Have you got data towards this? I can't dispute this with evidence beyond an observation that storage freezers are usually top access chests while daily use are front opening, mainly for convenience I suspect.

My intuition is that a front opening door must be less efficient over typical use just for the fact that when you open the door you're going to exchange more air. I'd believe that in a head-to-head comparison of two fridges left closed there's an insignificant difference.

The total available volume, insulation and mass of contents loaded is what counts.

And ventilation of hot air away from the condenser and electronics section.

The owner can improve that last, and add insulation with great effect.

Also keep fully loaded, and ideally pre-freeze all possible contents.

Better yet, build a custom box and install a marine kit, but pricey of course.

Agreed completely!

 

[67cj5]

They do **not** all use the same compressors, but within the Danfoss **style** that is not the source of significant energy efficiency differences.

The air issue is **very** insignificant, front-opening vs chest style no difference in AH per day consumption, which is the only measure that counts, and easy to get.

The total available volume, insulation and mass of contents loaded is what counts.

And ventilation of hot air away from the condenser and electronics section.

The owner can improve that last, and add insulation with great effect.

Also keep fully loaded, and ideally pre-freeze all possible contents.

Better yet, build a custom box and install a marine kit, but pricey of course.

I think you will find that most of the top brands use the Danfos BD35 in the small to medium fridges with the exception of Engel, Snomaster and now the latest Waeco's

And my fridge out performs most others even if it is only a 1/3 full, and the more I put in the better are it's cycle times, IE when it turns on for 14m 33 seconds and then shuts of for 2 hrs 5 minutes and 25 seconds or 125m 25secs, and that is when it is only a 1/3 full

I don't have any special box built for mine and it only has the factory cover on it,

And depending on how it is loaded gives it a longer and shorter run times along with longer and shorter "Off" times.

At present it hold 72 can and at the moment it only has 26 cans in it, Yet it is running for 14 to 15 minutes and shutting off for over 110 minutes So at roughly a 1/3rd full those numbers are quite impressive, And I have seen it run for 14m 29 seconds and then shut off for 2hrs 4 minutes and 50 seconds OR 124minutes 50 seconds.

My fridge does not need added insulation because it only drops 1*c in 4 hours/2*c in 8 hours 2 minutes. in the current ambient temp and even when it warms up it still returns a duty cycles of over 110 minutes, where it powers up for 14/15 minutes and then shuts off for 95 minutes, I am more than happy with those results.

 

[67cj5]

Have you got data towards this? I can't dispute this with evidence beyond an observation that storage freezers are usually top access chests while daily use are front opening, mainly for convenience I suspect.

My intuition is that a front opening door must be less efficient over typical use just for the fact that when you open the door you're going to exchange more air. I'd believe that in a head-to-head comparison of two fridges left closed there's an insignificant difference.

Yes Dave it is a well know fact that chest freezers are more efficient that upright models with a door opening, because in all fridge freezers the cold Air sinks to the bottom and if you are careful with a chest type fridge/freezer the cold air will stay in there, but with Door opening models the moment you open the door the cold Air rushes out the bottom.

 

[john61ct]

Widely believed myth, fully debunked by science.

 

[67cj5]

Widely believed myth, fully debunked by science.

What are you talking about ? Every thing I have posted is Fact, I have logged thousands of hours Timing On/Off Duty Cycles for weeks at a time, Just because your fridge does not behave the same doesn't change the Data on over One hundreds of pages of data that I have recorded with a stopwatch and 3 thermometers and 3 Watt Meters,

I have been testing these fridges for over 3 years so I have a pretty good understanding of the cause and effect of how they behave.

 

[DaveInDenver]

well know fact that chest freezers are more efficient that upright models with a door opening

Don't doubt, it's science! Cold air isn't actually flowing out when you open the door.

 

[DaveInDenver]

https://smarterhouse.org/food-storage/buying-tips

Buying a New Freezer
There are two basic freezer styles: upright (front loading) and chest (top loading). Chest freezers are 10–25% more efficient than uprights because they are better insulated and air doesn’t spill out when the door is opened. The current standard for freezers went into effect in September 2014. Look for ENERGY STAR to identify energy-efficient models. To qualify, full-size and compact freezers must use at least 10% less electricity than the federal minimum standards. Manual defrost freezers are more common than automatic defrost models, and they tend to do a better job at storing food. (Automatic defrost freezers may dehydrate frozen foods, causing freezer burn.) Because a stand-alone freezer is opened less frequently than a refrigerator-freezer, frost will generally not build up as quickly as it might in a manual defrost refrigerator.

Would be nice if it was not qualified with "better insulated", because that might be the difference in their statement.

 

[OpenTrackRacer]

The fridge ran 12 hours last night on a mostly charged new battery. Voltage this morning was 12.5 and the Jeep started right up. I'm annoyed I was chasing a battery problem but happy it was just a battery problem! My Whynter seems to draw around 4.5 amps with the compressor running at 12v.

 

[67cj5]

https://smarterhouse.org/food-storage/buying-tips

Would be nice if it was not qualified with "better insulated", because that might be the difference in their statement.

Yes Dave, Another thing to remember is simple physics cold air falls/drops and hot air rises so as the cold air falls out the door hot air rises to the top of the fridge and it has to repeat it's cycle all over again.

 

[67cj5]

This link will tell you all you need to know about the types of fridges and how to make your own,

https://shedheads.net/12v-refrigerator

 

[OpenTrackRacer]

This link will tell you all you need to know about the types of fridges and how to make your own,

https://shedheads.net/12v-refrigerator

That DYI is sort of ridiculous, especially when you add in the price of a suitable inverter.