diy solar

diy solar

My Dometic RV fridge is sucking my batteries dry and I can't determine why?!

This post claims 130 watts idle consumption.
diysolarforum.com

Idle Consumption: Is It Standby or Overhead?

Simple question. If an inverter has 100W idle consumption, and the other loads amount to 4000W during peak hours, then: A) During peak hours, total consumption is 4000W. At night, when there are no other loads, minimum consumption is 100W. In this case, idle consumption is standby. B)...
diysolarforum.com diysolarforum.com
 
Petenebraska said:
My installer says it's negligible.
Click to expand...
Very bad sign about your installer.

That inverter draws 100-110 watts idle, a little more when running PV SCC.

Check it with clip-on DC amp meter on battery cable with no AC load on inverter.

A 6kW inverter with only 200AH's of battery doesn't make a lot of sense either.
 
Last edited:
John Frum said:
You can't have both inverters connected to the ac distribution panel.
Please turn off the 12 volt inverter.
Do you have a dedicated ac2dc converter?
Click to expand...
This is how I understand the connection:
Solar panels and/or shore pwr connect to EG4, EG4 connected to 48v batts and breaker panel, breaker panel distributes 120v to outlets (A/C, microwave, fridge, water heater [when on] etc.) and also distributes 120v to original 12v ac2dc converter which is connected to 12v battery, 12v battery is connected back to fuse panel to distribute to 12v system in camper.

I can't turn off the 12v inverter. I lose lights, fridge control and all other 12v systems in the camper. (mainly lights)
 
400bird said:
What is powering the 12v system? What's keeping the 12v battery charged?
Click to expand...
This is how I understand the connection:
Solar panels and/or shore pwr connect to EG4, EG4 connected to 48v batts and breaker panel, breaker panel distributes 120v to outlets (A/C, microwave, fridge, water heater [when on] etc.) and also distributes 120v to original 12v ac2dc converter which is connected to 12v battery, 12v battery is connected back to fuse panel to distribute to 12v system in camper.

I can't turn off the 12v inverter. I lose lights, fridge control and all other 12v systems in the camper. (mainly lights)
 
Petenebraska said:
and also distributes 120v to original 12v ac2dc converter which is connected to 12v battery, 12v battery is connected back to fuse panel to distribute to 12v system in camper.
Click to expand...
This is a terribly inefficient way to convert power. At least some money was saved with the install.
 
Petenebraska said:
I can't turn off the 12v inverter. I lose lights, fridge control and all other 12v systems in the camper. (mainly lights)
Click to expand...
The 12 volt unit is a converter, it converts 120 volts shore power to 12 volts dc to run the 12 volt fixtures from AC shore power. There is a much better way to do that, a 48 volt DC to 12 volt dc converter, they are about 97-98% effeciency. Im using Samlex converters to provide 12 volts DC from my 24 volt battery banks. No sense in converting 48 volts DC to 120 volts AC Then reconverting from 120 volts AC to 12 volts DC. There is efficiency loss at every conversion.
All-in-ones are typically at under 85-90% effeciency when run at low power then the AC to 12 DC converter runs at about 88% effeciency for a net efficiency of 79% or so.
 
Tecnodave said:
The 12 volt unit is a converter, it converts 120 volts shore power to 12 volts dc to run the 12 volt fixtures from AC shore power. There is a much better way to do that, a 48 volt DC to 12 volt dc converter, they are about 97-98% effeciency. Im using Samlex converters to provide 12 volts DC from my 24 volt battery banks. No sense in converting 48 volts DC to 120 volts AC Then reconverting from 120 volts AC to 12 volts DC. There is efficiency loss at every conversion.
All-in-ones are typically at under 85-90% effeciency when run at low power then the AC to 12 DC converter runs at about 88% effeciency for a net efficiency of 79% or so.
Click to expand...
He said that he's waiting for some parts and that he'll build a plug-and-play DC2DC converter for me to install so I can remove the old 12 v system. I'm fine with installing that myself, and if that fixes the unusually large draw, I can live with it. However, if it makes more sense to remove the absorption fridge in exchange for a compressor, I'll look into doing that as well. Your thoughts??
 
Petenebraska said:
I"m sure it's running on electric only. And I read this article https://www.beginningfromthismorning.com/refrigerator/ suggesting that you are right about it burning tons of energy. My installer, though, is sure that it's supposed to be more efficient. We're trying to exhaust all possible options before throwing in the towel and buying a new fridge.
Click to expand...
You need a compressor fridge.

RV refrigerators are not efficient at all. They have. 300-500 watt heating element, no defrost etc. You're making heat to make cold. RV furnaces are also grossly inefficient. Their a/c's are also grossly inefficient. They are made to be cheap, compact and work a couple weeks out of the year.

In comparison, my free craigslist 12cf 20 year old compressor fridge uses about 1.2 Kwh a day. Draws about 120 watts when running.

You can get a nice fridge that uses like 50 watts or .5kwh hours a day if you get new.

Your current fridge is worth $$$ and will probably cover the cost of a compressor model.
 
Petenebraska said:
I can't turn off the 12v inverter. I lose lights, fridge control and all other 12v systems in the camper. (mainly lights)
Click to expand...
The 12 volt unit is a converter, it converts 120 volts shore power to 12 volts dc to run the 12 volt fixtures from AC shore power. There is a much better way to do that, a 48 volt DC to 12 volt dc converter, they are about 97-98% effeciency. Im using Samlex converters to provide 12 volts DC from my 24 volt battery banks. No sense in converting 48 volts DC to 120 volts AC Then reconverting from 120 volts AC to 12 volts DC. There is efficiency loss at every conversion.
All-in-ones are typically at under 85-90% effeciency when run at low power then the AC to 12 DC converter runs at about 88% effeciency for a net effeciency of

<EDIT> no idea how I posted this twice........
 
Last edited:
As a test I ran one Grape Solar dc compressor referigerator on one 50 watt solar panel and one very used Honda 50-60 amp hour battery on a hot sunny california day....did just fine, they do recommend one 100 watt panel and one 100 a.h. 12 volt battery at a minimum.

I now have three dc compressor refrigerators each with a different temperature zone, all running of my 24 volt DC solar system
 
Checkthisout said:
You need a compressor fridge.

RV refrigerators are not efficient at all. They have. 300-500 watt heating element, no defrost etc. You're making heat to make cold. RV furnaces are also grossly inefficient. Their a/c's are also grossly inefficient. They are made to be cheap, compact and work a couple weeks out of the year.

In comparison, my free craigslist 12cf 20 year old compressor fridge uses about 1.2 Kwh a day. Draws about 120 watts when running.

You can get a nice fridge that uses like 50 watts or .5kwh hours a day if you get new.

Your current fridge is worth $$$ and will probably cover the cost of a compressor model.
Click to expand...
That's the kind of out of the box thinking I like to read!
...still leaning that way.....

Thanks!
 
I too have a Samlex 24v all in one with a homebuilt 300ah 24 battery. I can run fridge/lights/furnace and my wifes cpap for several days no problem.
 
Petenebraska said:
He said that he's waiting for some parts and that he'll build a plug-and-play DC2DC converter for me to install so I can remove the old 12 v system. I'm fine with installing that myself, and if that fixes the unusually large draw, I can live with it. However, if it makes more sense to remove the absorption fridge in exchange for a compressor, I'll look into doing that as well. Your thoughts??
Click to expand...
The Danfoss compressor refrigerators are very definitely worth the cost, my Grape Solar unit was about $890 U.S. from home cheepo, Grape Solar no longer sells this unit but I have seen it with Sanyo name on it in the Phillipines but sadly not here in the lower 48 , (Native Alaskan for the Continental U.S.)
 
ABSORPTION FRIDGES USE A MASSIVE AMOUNT OF ELECTRICITY, TYPICALLY 5-6X AS MUCH AS A COMPARABLY SIZED RESIDENTIAL UNIT. DO NOT RUN ABSORPTION FRIDGES ON AC UNLESS YOU HAVE 5kWh OF BATTERY CAPACITY PER 7.6CU-FT OF FRIDGE VOLUME.

Yes. I run my absorption fridge on AC. However I have 3kW of AZ high desert PV and 23.3kWh of battery, AND the fridge is the only load besides 180W of "background" loads 24/7.

EDIT: Also worth noting that when we're on site and using lots of power for things we want, the fridge is running on propane. :)
 
Last edited:
Johneb said:
https://jc-refrigeration.com/ Check out these guys. They convert your fridge to a compressor fridge in less then a day. We had our Nevercold converted and love it. Uses a lot less energy.
Click to expand...
these look like replacement adsorption refrigeration units, not at all like what I am using.


<EDIT and update>
Looking more closely they do indeed offer updated tech. gas/electric units as well as what they are calling a “hvac” unit which does indeed does look to be a danfoss style compressor but more likely a Colku (chinese clone of the danfoss)
 
Last edited:
Petenebraska said:
Fascinating!! But for $1200, I'd be money ahead to just buy an off-the-shelf unit from Home Depot?? What prompted you to go with JC?
Click to expand...
Back then I didn't have the battery/inverter setup I do now. I have the 12 volt compressor model.
 
If I was to do it again I would just replace it with a standard fridge to get the extra space. About 2 cubit feet of extra space. If you can find an inverter refrigerator it will lower your energy level even more.
 
You must log in or register to reply here.

Similar threads

R
Fridge advice and guidance.
2 3
Replies
69
Views
3K
atelierminceur
atelierminceur
U
smoked my inverter and my mppt. looking for a 12V all in one?
2
Replies
31
Views
813
navydave
N
R
Converting propane fridge to 12v compressor
Replies
7
Views
492
MrBond
M
B
Will my Ecoflow Delta 1300 benefit from a solar cable with XT60i connector with 100 or 200 watts of solar panels or is XT60 good?
Replies
4
Views
479
Minimoose
M
G
Campervan solar batteries question
Replies
16
Views
655
0truck0
0truck0

diy solar

diy solar
Back
Top