Why consider 12v fridge for boondocking?

[Vintage465]

So I want to offer up this question out about 12v compressor refrigerators. I'm going to post this on other forums too, so your "forum tramps"(like me)may see this spread around some other pages. Not interested in thoughts regarding space savings, preferance due to fear of propane gas or performance of a 12v vs. propane fridge. Taking all those criteria out, we are left with why or why not. Having said all that this is the base of the question: I keep seeing people use the words "boon docking" and "12v compressor fridges" in the same sentance as though there is an advantage to having a 12v fridge while boon docking. I believe that an absorption fridge is the best boon docking choice because propane nearly lasts forever(at least a month) compared to 12v fridges that are dependent on recharging the battery bank daily. When responding...........not interested in anything other than energy sustainability while boon docking. I also am not interested in peoples opinions on performance between the two as I've never had any issue with any absorption fridge keeping things cool event in 110 degree temps. Just energy sustainability while boon docking.

Thanks!

[Vintage465]

Fisherguy wrote:

Vintage465 wrote:


... The day will come when everything will be 12v compressor and we will all need to adjust and by that time the solar and batteries will surely be up to the task.

And on that note I'm looking for advice. I have a chance to buy a trailer with 600 watts of solar panels, 3 - 100 Ah Lithiums and a 12 volt Norcold fridge.

I'll be installing a small inverter to power the TV and sat dish but no coffee makers or toasters etc for us.
If we only boondock do you think this setup will work for us? Maybe if I add another 200 watt panel and another 100Ah of Lithium?

We only very rarely need to run the genny to charge batteries with our current rig in my signature.
Thx

I think you have a good start there, but I'm certainly not any kind of expert on 12v longevity from a power stand point. But based on what you have and are willing to add to it you should be able hold out. You may encounter some issues if you winter camp using that kind of energy.

[ktmrfs]

StirCrazy wrote:
when it comes to power usage, a 12V is not near as energy efficient (battery power wise) as an adsorbition fridge. you will need much more battery capacity and solar or a generator if you switch to 12V compressor.

In terms of BTU or KWH needed to cool, compressor driven fridges are much more efficient than a absorption fridge. Generally you can get about 3x the input BTU used in cooling BTU from a compressor driven fridge. No it doesn't violate any laws of physics, it's the energy needed to move heat from one place to another.

By contrast an absoprtion fridge is much less efficient COP is on the order of 0.7 or less vs 3 or more for compressor fridges.

But in terms of how the energy is stored to use the fridge, propane in BTU/gallon or BTU/weight or BTU/volume FAR FAR FAR exceeds any battery for the same volume or weight.

[JRscooby]

How many people have how much experience with 12 V fridge? I know mine is limited, but I was impressed.
Friend had 1 installed in his new '99 Pete when he bought it. (Has technology improved in 20+ years?) Summer of '12, he had to leave the rig in Dallas area truckstop, catch bird home. (Ever see a shadetree in truckstop? Parked in Dallas summer?) Called his brothers and I, hoped to get load delivered ASAP, and truck home. By the time I got there, truck had been setting 3 days. And because he only had same batteries to crank his Cat I did, I assumed would need a jump start. Hit the button, cranked like normal. Assumed the fridge had shut itself off to save batteries, so grabbed a trash bag to get rid of the stinky mess. Opened the fridge, stole a icecream bar, and headed out.

[Fisherguy]

Vintage465 wrote:


... The day will come when everything will be 12v compressor and we will all need to adjust and by that time the solar and batteries will surely be up to the task.

And on that note I'm looking for advice. I have a chance to buy a trailer with 600 watts of solar panels, 3 - 100 Ah Lithiums and a 12 volt Norcold fridge.

I'll be installing a small inverter to power the TV and sat dish but no coffee makers or toasters etc for us.
If we only boondock do you think this setup will work for us? Maybe if I add another 200 watt panel and another 100Ah of Lithium?

We only very rarely need to run the genny to charge batteries with our current rig in my signature.
Thx

[Vintage465]

ktmrfs wrote:

Vintage465 wrote:
Though I have enjoyed reading all the comments, I should have been more specific when I started this thread many months ago. I was only looking for an energy saving advantage use of a 12 compressor fridge over and absorption fridge......nothing else. We primarily boon dock. And as I think I have stated in some of the comments, I've read on many RV reviews...."it has a 12v compressor fridge making perfect for boon docking". Reading a phrase like that indicated to me that there could be an energy saving advantage to having a 12v fridge that I wasn't aware of. What many people saw was the opportunity to share thier "preference" reasons for using 12v compressor fridges.....which is fine, but not what I was looking for and occasionally gets under peoples skin when discussing the politics of why and why not to have one fridge vs another type. And incidently I've never had any issues with our Norcold absorption fridge keeping things cool at temps over 100 degrees or down to 7 degrees.

a compressor driven fridge is likely much more energy efficient than an absorption fridge in terms of watt/hrs needed. BUT the energy density/wt or volume for propane is orders of magnitude better than any current battery choice. So it takes way less area and wt to store the "fuel" supply for a propane fridge vs. compressor driven if your not hooked to a line power source.

And I guess this sums up me not being specific enough. I'm thinking
"on board" energy that is available to use for cooling purposes. In my mind, a coach with a built in solar array of say, 500w, four 6v batteries and two 7 gallon propane tanks is pretty normal for many boon dockers out there. Some have more, some have less. With a setup similar to this, take a compressor fridge vs an absorption fridge, I'm pretty sure that on all but the best day, the absorption will win. So I'm not necessarily interested in the energy invested in the cooling unit to create a btu drop. It may ulimately take less energy in a clinical setting to achieve sufficient cooling from a compressor unit, but having that energy available thru a large battery bank, solar and generator is far more cumbersom that a couple 7 gallon bottles of gas that is neatly and normally stowed away. And on those two bottles of gas I can easily make it 30 days in spring and fall. Winter time I'll need to fill up in a couple weeks. Anyway, just me....The day will come when everything will be 12v compressor and we will all need to adjust and by that time the solar and batteries will surely be up to the task.

[StirCrazy]

when it comes to power usage, a 12V is not near as energy efficient (battery power wise) as an adsorbition fridge. you will need much more battery capacity and solar or a generator if you switch to 12V compressor.

[ktmrfs]

Vintage465 wrote:
Though I have enjoyed reading all the comments, I should have been more specific when I started this thread many months ago. I was only looking for an energy saving advantage use of a 12 compressor fridge over and absorption fridge......nothing else. We primarily boon dock. And as I think I have stated in some of the comments, I've read on many RV reviews...."it has a 12v compressor fridge making perfect for boon docking". Reading a phrase like that indicated to me that there could be an energy saving advantage to having a 12v fridge that I wasn't aware of. What many people saw was the opportunity to share thier "preference" reasons for using 12v compressor fridges.....which is fine, but not what I was looking for and occasionally gets under peoples skin when discussing the politics of why and why not to have one fridge vs another type. And incidently I've never had any issues with our Norcold absorption fridge keeping things cool at temps over 100 degrees or down to 7 degrees.

a compressor driven fridge is likely much more energy efficient than an absorption fridge in terms of watt/hrs needed. BUT the energy density/wt or volume for propane is orders of magnitude better than any current battery choice. So it takes way less area and wt to store the "fuel" supply for a propane fridge vs. compressor driven if your not hooked to a line power source.

[Vintage465]

Though I have enjoyed reading all the comments, I should have been more specific when I started this thread many months ago. I was only looking for an energy saving advantage use of a 12 compressor fridge over and absorption fridge......nothing else. We primarily boon dock. And as I think I have stated in some of the comments, I've read on many RV reviews...."it has a 12v compressor fridge making perfect for boon docking". Reading a phrase like that indicated to me that there could be an energy saving advantage to having a 12v fridge that I wasn't aware of. What many people saw was the opportunity to share thier "preference" reasons for using 12v compressor fridges.....which is fine, but not what I was looking for and occasionally gets under peoples skin when discussing the politics of why and why not to have one fridge vs another type. And incidently I've never had any issues with our Norcold absorption fridge keeping things cool at temps over 100 degrees or down to 7 degrees.

[Reisender]

Yah I hear you. Hence our back up plan with our little propane generator. :).

[Huntindog]

Reisender wrote:

Huntindog wrote:

bironacad wrote:
Just purchased a Grand Design TT with a DC fridge. The fridge is 8 cubic feet and It cools down very fast compared to an absorption fridge and you can run it while on the road. The antenna booster draws 1amp while on, the fridge 3. The trailer does come with a 165 watt solar panel. I like the fridge capacity size increase. Thinking of adding another panel and upgrading battery to lithium to run an inverter for AC when required while off grid. I think both have advantages. I started with a pop up, then went with a 28’ fifth wheel, then a 40’ Red Wood, drop down to a hybrid and now have the 200 mk trandscend. Lol heading to Yukon this August and will know much more after that trip. Lol enjoy what you have! And don’t stand with the door open. Play safe.

I just looked up the Furrion 12V, 8CF fridge.

High efficiency DC compressor
Input voltage: DC 12V (min. DC 10.5V to max. DC 17V)
Input power rating: = 15A (11A @ 12V DC)
Energy Consumption: 1.08kWh per day.
.
You will need a LOT more solar as well to feed the batteries.
Basically you will have a math problem. one 100AH Lithium battery will be drained everyday by the fridge alone.
Solar averages about 60% of rated output.
You can do the math however you like. I see you comming up way short.

Yah. It’s an easy and reasonably problem to solve with solar but of course you need the real estate to put it on. Smaller trailers and tear drops will have a bigger challenge than medium sized trailers. Glad we have a propane fridge but if it quits we’ll need to figure it out.

We noticed that the new 2023 version of our trailer has 2 kw of LFP batteries as standard with a 6 kw option. All installed under the bed. (That’s where our AGM’s are). I think that was in response to customer complaints about the compressor fridge power usage.

With enough money it can be solved if you are a fair weather camper. I am not. If I only camped in good weather, I would not need an RV. I have the RV for shelter in comfort no matter what mother nature does.I have a healthy solar/ battery system.But as my last trip proved, 6" of snow on the roof renders solar useless. In a 4 week outing it snowed 6-8" three times. Generator use was required. A 12V fridge would have just added to the fuel bill

[Grit_dog]

Merry Xmas! Almost a whole year under the belt of this thread….
And math wins again. These conversations wouldnt be near as fun if everyone could actually math.

[Reisender]

Huntindog wrote:

bironacad wrote:
Just purchased a Grand Design TT with a DC fridge. The fridge is 8 cubic feet and It cools down very fast compared to an absorption fridge and you can run it while on the road. The antenna booster draws 1amp while on, the fridge 3. The trailer does come with a 165 watt solar panel. I like the fridge capacity size increase. Thinking of adding another panel and upgrading battery to lithium to run an inverter for AC when required while off grid. I think both have advantages. I started with a pop up, then went with a 28’ fifth wheel, then a 40’ Red Wood, drop down to a hybrid and now have the 200 mk trandscend. Lol heading to Yukon this August and will know much more after that trip. Lol enjoy what you have! And don’t stand with the door open. Play safe.

I just looked up the Furrion 12V, 8CF fridge.

High efficiency DC compressor
Input voltage: DC 12V (min. DC 10.5V to max. DC 17V)
Input power rating: = 15A (11A @ 12V DC)
Energy Consumption: 1.08kWh per day.
.
You will need a LOT more solar as well to feed the batteries.
Basically you will have a math problem. one 100AH Lithium battery will be drained everyday by the fridge alone.
Solar averages about 60% of rated output.
You can do the math however you like. I see you comming up way short.

Yah. It’s an easy and reasonably problem to solve with solar but of course you need the real estate to put it on. Smaller trailers and tear drops will have a bigger challenge than medium sized trailers. Glad we have a propane fridge but if it quits we’ll need to figure it out.

We noticed that the new 2023 version of our trailer has 2 kw of LFP batteries as standard with a 6 kw option. All installed under the bed. (That’s where our AGM’s are). I think that was in response to customer complaints about the compressor fridge power usage.

[Huntindog]

bironacad wrote:
Just purchased a Grand Design TT with a DC fridge. The fridge is 8 cubic feet and It cools down very fast compared to an absorption fridge and you can run it while on the road. The antenna booster draws 1amp while on, the fridge 3. The trailer does come with a 165 watt solar panel. I like the fridge capacity size increase. Thinking of adding another panel and upgrading battery to lithium to run an inverter for AC when required while off grid. I think both have advantages. I started with a pop up, then went with a 28’ fifth wheel, then a 40’ Red Wood, drop down to a hybrid and now have the 200 mk trandscend. Lol heading to Yukon this August and will know much more after that trip. Lol enjoy what you have! And don’t stand with the door open. Play safe.

I just looked up the Furrion 12V, 8CF fridge.

High efficiency DC compressor
Input voltage: DC 12V (min. DC 10.5V to max. DC 17V)
Input power rating: = 15A (11A @ 12V DC)
Energy Consumption: 1.08kWh per day.
.
You will need a LOT more solar as well to feed the batteries.
Basically you will have a math problem. one 100AH Lithium battery will be drained everyday by the fridge alone.
Solar averages about 60% of rated output.
You can do the math however you like. I see you comming up way short.

[Huntindog]

ktmrfs wrote:

bironacad wrote:
Just purchased a Grand Design TT with a DC fridge. The fridge is 8 cubic feet and It cools down very fast compared to an absorption fridge and you can run it while on the road. The antenna booster draws 1amp while on, the fridge 3. The trailer does come with a 165 watt solar panel. I like the fridge capacity size increase. Thinking of adding another panel and upgrading battery to lithium to run an inverter for AC when required while off grid. I think both have advantages. I started with a pop up, then went with a 28’ fifth wheel, then a 40’ Red Wood, drop down to a hybrid and now have the 200 mk trandscend. Lol heading to Yukon this August and will know much more after that trip. Lol enjoy what you have! And don’t stand with the door open. Play safe.

If the fridge only draws 3A when cooling on 12V it's an outstanding fridge and I'd go for it, that's only 36W. I've never seen a compressor fridge at less than 150W or so. Now if the 3A is 120V, sounds reasonable, but that is about 40A on 12V operation.

I have heard that these newer fridges are designed so that the compressor aways runs. If that is true, then over a 24 hour period it would draw 72 AH. That is a figure that I find believable...But would sure put a hurt on the battery.

[Reisender]

12 volt compressor fridges are the way to go if you have a good solar array and a good battery bank. They are better in hot weather and considerably larger inside for the outside footprint.

For those of us with smaller roof real estate for solar and limited battery bank space a propane fridge may be a better choice.

Simple answer is…it depends. 🙂