If you boondock a lot . . .

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I don't know Don, your article with the 3 degrees was good but it didn't mention what the specs were years ago only that it was more lenient today.

I checked the manual that comes with the Dometic RM2510 fridge and here's what it says.

LEVELING
Refrigerators have a type of cooling unit that utilizes an enclosed pump tube surrounded by a solution to protect the
assembly. To ensure proper leveling with these models, the vehicle needs to be leveled so it is comfortable to live in.
(No noticeable sloping of floor or walls). When the vehicle is moving, leveling is not critical as the rolling and pitching
movement of the vehicle will pass to either side of level, keeping the refrigerant from accumulating in the piping.

It doesn't give any numbers so I don't know how to make a conclusion. If we conclude that comfortable to live in is within 3 degrees off level then nothing has changed in the last 30 years. If we assume that the new ones are better then Dometic must have thought 4 or more degrees off level was unnoticeable and comfortable.

Tough to call.

EDIT: The other quirk is that I have now rebuilt my refrigerator with a new cooling unit from the Amish, I don't know if it's more or less tempermental than the OEM of 1992 or 2021.
 
Here's a technical drawing of a cooling unit. I made some highlights.

See the red lines? They represent an angle that causes the water to drain back to the pump - labelled B in blue.

As I understand it the way the pump works is that the flame or heating element heats the water in the outside jacket, this water then heats the ammonia in the inside jacket. It's a double boiler, a little like how we melt chocolate by putting it over another saucepan of boiling water. You wouldn't want to put a flame directly onto a tube full of ammonia because you'll crystallize it, the flame is way too hot but the water shouldn't get much hotter than 212F which is fine for evaporating ammonia.

Both water and ammonia evaporate and rise up and the angle of the tube at point A in blue makes sure that the water separator returns the water to the pump, if the trailer or RV is out of level and the water runs past point A and into the condensor the refrigeration cycle won't work and the boiler can run out of water and the ammonia solution will heat too high and start to crystallize.

The angle in the picture is a little exaggerated, in the actual units (mine at least) it was about 3 or 4 degrees.
 

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Nice diagram and explanation JayArr. I don't think the degrees are like those on a protractor, but maybe I'm just being dense. I have a set of stick on levels on the exterior of the trailer (lost the side to side one however after 2 years) and they are marked with numbers 0 in the middle and then 1-6 going both left and right. The below diagram from the video matches up well with what I see in terms of angle from level on these I think. I also have a carpenters level like the one in the video, so if I think I'm not level side to side, I'll just eyeball where the bubble is and compare it to the one with numbers. Only have had to do this 2-3 times however. Hope this makes sense.
 

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Nice diagram and explanation JayArr. I don't think the degrees are like those on a protractor, but maybe I'm just being dense. I have a set of stick on levels on the exterior of the trailer (lost the side to side one however after 2 years) and they are marked with numbers 0 in the middle and then 1-6 going both left and right. The below diagram from the video matches up well with what I see in terms of angle from level on these I think. I also have a carpenters level like the one in the video, so if I think I'm not level side to side, I'll just eyeball where the bubble is and compare it to the one with numbers. Only have had to do this 2-3 times however. Hope this makes sense.
I think you'll find that the numbers on the little black level refer to the number of inches of packing you need under the wheels to get the unit level.
 
Nice diagram and explanation JayArr. I don't think the degrees are like those on a protractor, but maybe I'm just being dense. I have a set of stick on levels on the exterior of the trailer (lost the side to side one however after 2 years) and they are marked with numbers 0 in the middle and then 1-6 going both left and right. The below diagram from the video matches up well with what I see in terms of angle from level on these I think. I also have a carpenters level like the one in the video, so if I think I'm not level side to side, I'll just eyeball where the bubble is and compare it to the one with numbers. Only have had to do this 2-3 times however. Hope this makes sense.
Linda. Those degrees spoken of are exactly the same thing. It's called geometry. And Tony is right. That stick-on level tells how much you need to raise or lower an end of your trailer. And just to confuse you more: don't confuse the degrees in geometry/trigonometry with temperature degrees.
You can download a level app for your phone. It needs to be calibrated before you trust though.
 
If you are boondocking, I would stay away from any non lp fridge. Who wants to hear a generator running all the time and if you do not run it you will need a lot of batteries and solar panels. George
 
Who wants to hear a generator running all the time and if you do not run it you will need a lot of batteries and solar panels.
Yep, that was the main deal breaker to me with the Thor Axis, as I was looking for the smallest Class A possible. I will just have to get used to my larger . . . .

A little longer than I wanted, cost a bit more, but has everything I want otherwise in my new rig.

-Don- Auburn, CA
 
Wow, the first 4 post were from people who do not own, never owned and know little about the topic. Wow, just wow.
So, i skipped to the end.
AND, no they do NOT pull 8 amps as the user who has never owned or used or seen one posted.
They pull 5 to start up and 3-4 to keep running, WHEN they are running and ZERO when they are not running, so you do the math for amp hour use, not surge amp peak.
The TRICK to these DC compressor Danfoss units is to really, really insulate the cooler. I used 1 inch styrofoam on the bottom and 2 inch on the sides. Not the blanket or bags or covers they sell for these, but real styrofoam that is pressed solidly to the sides of the cooler.
My unit runs a fraction of the time that it used to run and my batteries are barely depleted by morning.
A big bonus is that when it does run it is a lot more quiet due to the insulation.
These units are IT! I would never go back to a propane fridge unless the camper were going to sit parked all the time and I had no sun.
Residential fridges are for parked trailers connected to the grid.
Anything else is waste.

They KEY is to have solar. 200-300 watts min. Unless you are driving everyday to recharge the batts.

answer to another: no, the converter/charger only charges the batteries. all the DC things run off of batteries, not the converter. The converter charges the batteries, but it is really all the same, it is just best to think of it as run off batteries, charge with converter/charger. If you say it runs off the converter then you are not wrong. The converter is connected to the battery, so everything is always running off the battery unless you take the battery out.
The converter part is converting from 120v to 12v. The charger part is charging the battery.
 
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no, the converter/charger only charges the batteries.
You can remove the house battery and run from the converter.

When connected up normally, the converter voltage is higher than the battery voltage would be. The converter then supplies the current to the house stuff more so than the battery. IMO, that means you're running from the converter, not the battery, whenever you have shore power to the converter.

-Don- Reno, NV
 
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like I said, think of it as running from the battery. In reality it runs from both. Its like pouring water into a bucket with a hose and dipping your cup in the bucket. Did you get water from the hose or the bucket? Dumb question in the end and nearly pointless to ask. You got it from the bucket that has hose water pouring in. Until you isolate one you get both.

I think the intention of OP question was that no, the converter does not remove the battery from the equation, the battery is always doing battery things for the RV.
 
They KEY is to have solar. 200-300 watts min. Unless you are driving everyday to recharge the batts.
spoken by someone who knows little about the topic..

here are some real figures for you using your 4 amps figure.

48x24x1.5/4= 432 Watts of panels with 4 sun hours. ;)
 
what does the 48, 24, 1.5 mean and what kinda number is 4 hours of sun?
Then I can help you out. I would be a guy who knows a LOT, here to help...
 
They KEY is to have solar. 200-300 watts min.
But some of us would rather use that ~250 watts to help keep our house batteries charged than to run a refrigerator.

Besides that, the 2022 Thor Axis with the 8 amp refrigerator only has 100w of solar.

-Don- Reno, NV
 
8 amps is a lot and some of those bigger units will pull that. Most pull less, but you dont care about those, lol.
IF you pull double the amps then you need double to supply it. Not double batteries, because everything else you are doing is not double the power, but you will need more than 100 watts solar to live with. 100 is not enough for a fridge that pulls 3 amps.
6 panels would be better for 8 amp fridge, and your front-open fridge is not as well insulated as those chest fridges, so it will be running more of the time.
For the math, you do not multiply the 8 amps by number of hours. So, for a 3-day trip it IS NOT 8x36=288 amp hours. You must know how much your fridge runs. lf it runs 20% of the time then you would have 57 amp hours instead (20% of 288). This is total use for 3 days, not the battery power needed since solar is involved.
For 12 hours, not 96aH , but is 19 amp hours, which is about what overnight use is. You will have solar in the day on sunny days so will run off of the sun. With enough solar panels you can recharge your batteries and have spare power to run fridge and other things too.
Remember you use lights and fans and inverters and tv's and chargers at night too which consume amps. The fridge should be the biggest draw though.
 
The fridge will draw he same power. All the DC compressor fridges I am familiar with are 12 or 24 volt DC. The shore power/120 volt AC is converted to 24 volt DC before it is sent to the compressor and fan, so the fridge always runs on DC current (it just converts the AC current to DC when on shore power).

For that matter, most things run on DC, your house TV is actually a DC device, the TV just has a converter to turn the 120 volts to DC power before the TV electronics use it. Most things in your house except fans and heaters and lights are DC. Anything with a motor like a fan, blender, vacuum cleaner etc is AC. Anything with a heating element like a heater, hair drier, curling iron etc are AC. Most all electronics are DC (with converters/transformers built in or in the plug). Stereo is DC.
 
what does the 48, 24, 1.5 mean and what kinda number is 4 hours of sun?
Then I can help you out. I would be a guy who knows a LOT, here to help
any solar engineer or EE would recognize those figures..
however, here is a detail explanation..

48 is the Wattage ( 12 V x 4 A )
24 is the number of hours in a day, the daily watt/hr figure is therefore (24*48) 1152 W/hr
1.5 is a correction figure we typically use to allow for converter and battery inefficiencies.
4 sun hours is a typical average insolation figure for the mid west in winter.
more particularly described as peak sun hours were intensity is 1000 W per square meter.
although sunlight may be available for 10 hours a day in certain locations, the peak energy is not and therefore one designs systems based on peak insolation values. there are good example tables from NASA/NREL etc..

so if you camped in the midwest in winter, you would need approx. 430 W of panels to run
your fridge 24/7

just FYI, i'm a licensed professional engineer who designs off grid systems, i'm here to help too..
 
LOL. Admitting you are an engineer is the first step towards getting help... That degree means nothing to me, but let's try to help each other nevertheless.

Your big miss mr engineer is that the compressor fridge does not run all the time. That is my pet peeve for people answering forum post who do not have experience with the subject. No offense, but people who own compressor fridges know they do not run 100% duty cycles. You know what you know, but not what you need to know. Now you know more.
I can't tell the OP what % his fridge runs. I just guessed 20% as a round number. This means 12 minutes of every hour. So every 5 hours you get a full 60 minutes of run time. Probably that big front door fridge runs more.
As you know in reality, the solar panels work in morning and evening light. My panels will have the system charged back sometimes before I get up, before your 4 hour imaginary window. Panels do not need to be at 100% efficiency to do work. They are always at 18 volts but the amps vary with light.
My fridge starts up with 4 amps and runs on 3 amps, the battery will be back to full voltage, even with the fridge still on, in the morning off of only 200 watts, before the magic hour, in the forest woods. I also run lights and fans and charge devices etc.
The panels will have extra capacity available during a normal sunny day, so the battery will not be drained in the daytime. Batts will charge and run the electric items at the same time. I always try to charge my devices early in the day when the sun can charge it so I start the evening with full battery and no drain from chargers.
Doing math is good but you have to consider all variables. Leaving some out ruins it all. Thinking an 8 amp fridge will pull 192 amp hours (2304 watt hrs I guess) in one day is a big doodo.
For the 20% duty cycle possibility then 460 watt hours if I did that right. I use amp hrs not watts. You used 4 amps in your math, so thats just half, so 230 watt hours not the 1152 you came up with. The fridges must run more than 20% of the time because these are small numbers, but they do not run all the time.
So, there ya go. Hope this helps.

So for a big 8 amp electric fridge it is a harder decision to make than for a 3 amp fridge because you will need a bigger battery bank than most RVers have to cover for cloudy/rainy days.
My experience is that it is worth getting more battery to have the electric fridge. They do not need to be level and can run 30 Degrees off level and be fine, vs the 3 degrees the propane ones tolerate.
I would get an electric induction cooktop if I were to do it over, and just keep a camping stove for backup.
Batteries can last 6-10 years. If say 7 years then a $600 set of batteries cost $85 per year. Propane is $17-22 or so per tank. You have to have batteries anyway, so lets say normal would be a $300 set of batteries, but you did a $600 set for the electric needs, so thats an extra $43 per year or two tanks of propane. You still need propane, but a full time boondocker will need 1 tank just to run a fridge per month times 12 = 500/year. yikes. Even if my math is off a little bit these are big numbers.
 
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