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Author Topic: Power Consumption 12 V Cooler VS 12 Fridge  (Read 115 times)

MaxfieldMax

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Power Consumption 12 V Cooler VS 12 Fridge
« on: August 12, 2017, 11:49:32 AM »
Hello everyone.
Do you guys have any experience with cooler and fridge in term of power consumption?
From what I read online.First they both can operate on 12 V.  For a more specific example. 
FM-45G Whynter 45 Quart Portable Fridge Voltage power AC (115V/ 60Hz 65W/ 0.75A) or DC (12V/24V 4.5A /2.5A Car Lighter Socket)
On the other hand,  Coleman 40-Quart Wheeled Cooler 12V plug (5 Amps/60 Watts) with an 8-ft.
Which one requires more power to operation continuously to keep drink cool, 24/7
From what I read online, the fridge seems like require less power because they don't alway run compressor.
On the other hand, the cooler will run the fan always, which end up requiring more Amp hours to run them 24/7. Is that correct?

Assume, You are two 12 V batteries in parallel, which has total 270 amp hours. At the same time, you have a 100 Watt solar panel to charge the batteries. Do you think if can run the cooler 24/7 with the current setup?
Thank you so much for all your inputs

Camper_Dan

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Re: Power Consumption 12 V Cooler VS 12 Fridge
« Reply #1 on: August 13, 2017, 06:23:35 AM »
Greetings & Welcome!

None of the 12v coolers are meant for anything more than occasional weekend/vacation use.  They have a very short lifespan when used daily.  The new compresssor fridge/coolers are cheap chinese junk, and their lifespan is about a year for daily use.  The thermo electric coolers are cheaper and have a longer lifespan of about 2-3 years, but they will only cool down to about 40f degrees below surrounding temperature, and in a van that could mean 140f inside the van.  Either will use about 100 amps per day, the thermo electric ones possibly a little less.  (The fan by itself uses practically no power.)

Of the two, the compressor fridges do the best job when they're working, but their short lifespan makes them terribly expensive.  Generally speaking, experienced full timers use either 3 way propane/electric/12v fridges, or ice chests.   In the end, the ice chests cost far less than any other option, and they require no power, which is HUGE when power is at a premium.  I use one $0.99-$1.99 block of ice per week in my 40qt ice chest.  The trick is to keep the ice in a separate container, so your food never gets wet, and your ice lasts longer.  If I'm in extreme heat, I will also wrap my ice chest in a moving blanket.

There are a lot of people who promote solar panels, yet statistics show that fewer than one in a hundred ever ends up with a system that meets their needs, and fewer than one in a hundred of those would ever do it again.  Solar panels are the most expensive and the worst possible choice for power.  Parking in the sun during the summer with a huge heater on your roof is pure hell, and solar panels tend to kill batteries rather quickly when compared to other charging methods.  Any fulltimer will tell you that you want shade in the summer, and the efficiency of solar panels in the winter drops dramatically.

The typical motorhome methods of charging batteries is preferred by most fulltimers, charge while driving, via a generator, or via shore power.  All  of these methods will give you a better and deeper charge than solar panels will, and your batteries will last much longer.  Deep cycle batteries are usually rated for around 100-150 charge cycles.  With solar you are cycling them every day, and your batteries rarely last longer than about a year.  With the better methods, and only cycling them weekly will give you 6-7 years on those same batteries.

Extreme power conservation while on battery power seems to be the most effective solution.  If your electronics need charging, try to charge them while driving, along with the house battery(s).  Some people also charge their electronics at libraries, coffee shops, etc. 

I always suggest that solar panels should only be considered AFTER you already have a totally functioning system.  If you decide to do that, considering all the  inefficiencies of solar, for 270ah worth of batteries, I would suggest a minimum of 540 watts worth of solar panels.

Freetasman

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Re: Power Consumption 12 V Cooler VS 12 Fridge
« Reply #2 on: August 16, 2017, 12:40:31 PM »
MaxfieldMax,
Forget about coolers, the use a lot of power and are not efficient.
A portable fridge with a compressor like the Danford will be the best option.
Regarding power consumption here is a good article:
https://www.caravansplus.com.au/catalog/help-12v-battery-size.php

I have used Waeco fridges with Danford compressors and are very efficient.

mischievous

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Re: Power Consumption 12 V Cooler VS 12 Fridge
« Reply #3 on: August 16, 2017, 07:04:31 PM »
Along the same lines:

Refrigerator: One option is to buy a chest design Dometic, or similar, higher end 12V fridge / freezer. Another is a small apartment type residential fridge and power it off the inverter.

I will have 3 each - 70AH Trojan 24-AGM house batteries. They will connect to a 5000 watt sine wave inverter / charger. Dang Keurig takes 1500 watts, for 1 to 3 minutes. Plus the alternator will be used for charging. The alternator will use an isolator. Plus the vehicle battery will have a low level detector to open the isolator.

Thoughts??
Be well. Have fun.

Camper_Dan

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Re: Power Consumption 12 V Cooler VS 12 Fridge
« Reply #4 on: August 16, 2017, 11:28:55 PM »
MaxfieldMax,
Forget about coolers, the use a lot of power and are not efficient.
A portable fridge with a compressor like the Danford will be the best option.
Regarding power consumption here is a good article:
https://www.caravansplus.com.au/catalog/help-12v-battery-size.php

I have used Waeco fridges with Danford compressors and are very efficient.

I think you are referring to the Dan Foss compressors, not Danford...  It should also be noted that while many of these newer fridges claim to use Dan Foss compressors, they are actually cheap knock offs MAYBE using the Dan Foss design, but are not genuine Dan Foss compressors.  The jury is still out on the newer Sawafuji swing type compressors...

While most of the older 12v compressor type fridges were better built, and would last about 5 years under everyday use, the same is no longer true.  Today's versions are cheap junk and have a lifespan of only about a year when in permanent use.  They are all designed for occasional use, not full time use, and they just don't hold up well.  Of the last 3 I've had, not a single one of them made it to the 1.5 year mark.  Before that, I had an old one that lasted a little over 5 years.  To top that off, they all want $600+ plus shipping to repair them! 

One interesting development that has not withstood the test of time yet is a dorm fridge with an inverter, with a twist.  They hook up the inverter to a temperature controlled shut off, to eliminate the inverter draw when the fridge isn't running.  This setup is reported to use less than half the power of those 12v fridges at a fraction of the cost.

Electric fridges have lost favor with most experienced full timers unless they spend the majority of their time somewhere that has shore power.  For those who do a lot of time away from shore power, the 3 way fridges with the propane option are preferred.  They last longer and require no power.  A few of the really old timers still have kerosene powered fridges, but at this point in time, they are almost impossible to find.

All the mumbo jumbo about solar panels and 12v fridges is salesman double talk.  Shade in the summer is what you want, and shade and solar panels don't go well together.  140f degree plus vans parked in the sun, and fridges of any kind don't go well together either, and certainly can't be considered energy efficient by any stretch of the imagination.  When it comes to fridges, or even ice chests for that matter, shade is your best friend in the summer.

There are many things that can be made to sound good in writing or in advertising, but that just aren't practical for full time vehicle dwellers.  Many of us have come to the conclusion that both solar panels and 12v fridges fall into that category.

Camper_Dan

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Re: Power Consumption 12 V Cooler VS 12 Fridge
« Reply #5 on: August 17, 2017, 12:39:41 AM »
Along the same lines:

Refrigerator: One option is to buy a chest design Dometic, or similar, higher end 12V fridge / freezer. Another is a small apartment type residential fridge and power it off the inverter.

I will have 3 each - 70AH Trojan 24-AGM house batteries. They will connect to a 5000 watt sine wave inverter / charger. Dang Keurig takes 1500 watts, for 1 to 3 minutes. Plus the alternator will be used for charging. The alternator will use an isolator. Plus the vehicle battery will have a low level detector to open the isolator.

Thoughts??

A 5000 watt inverter is considerable overkill generally speaking.  Inverters are terribly inefficient, drawing power even when not in use, and the bigger the inverter, the larger that power draw is.  Many of us  prefer to never use an inverter, and those that do seem to recommend using the smallest inverter possible for  the load needed.  Many items are also available in more efficient 12 volt models as well.

Vehicle dwelling without shore power is a whole different world than living in a house with normal electricity.  Power can become a very precious commodity, and anything having anything to do with heating, cooking, refrigeration, or normal household electrical appliances, are frequently best served by way of a generator rather than battery power, or some other type of work around that doesn't require battery power.  Deep cycle batteries don't like huge draws even if it is for a very short time.  Vehicle starter batteries are designed for short, high output draws, then an immediate full recharge, but deep cycle batteries are not.

Isolators are the #1 preferred way to charge house batteries.  Generators are the #2 way to charge house batteries for boondockers, and the  #1 way to provide shore power while boondocking for anything that requires more than maybe 10 amps @ 12 volts.  Your Keurig would draw 125 amps @ 12 volts plus whatever the inverter loss would be. (Usually 10-25%)  Perhaps a stove top (camping stove) coffee maker would be a better choice to help you prolong the life of your house batteries.