diy solar

diy solar

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

So I'm guessing the old Fridge is still running off of the 12volt system??
So if you turn off the 48 volt inverter does the Fridge still run? If so then it is still on the 12 volt system.
As other post Yes you can get a buck converter to go from 48 volt DC to 12 Volt DC, but cheap ones will fail. Also you will need one that can run all of your 12 volt systems (total wattage). Personally I would keep both systems and run only your high power stuff the house part on the 48 volt inverter. You could also test the consumption of the Fridge using a KWH Meter for about $35.00 amazon that will show you the total KWH per day etc.
 
ShanePowerHouse said:
So I'm guessing the old Fridge is still running off of the 12volt system??
So if you turn off the 48 volt inverter does the Fridge still run? If so then it is still on the 12 volt system.
As other post Yes you can get a buck converter to go from 48 volt DC to 12 Volt DC, but cheap ones will fail. Also you will need one that can run all of your 12 volt systems (total wattage). Personally I would keep both systems and run only your high power stuff the house part on the 48 volt inverter. You could also test the consumption of the Fridge using a KWH Meter for about $35.00 amazon that will show you the total KWH per day etc.
Click to expand...
It's still hooked up to 12v, but only the circuit board is running on 12v. It senses if there is 120v and toggles between propane and ac when the unit is "on". If I turn off the 48v inverter, the fridge will just switch over to propane since it doesn't sense the 120v coming in anymore.

I'm going to talk with my installer (who has read this post string and has several constructive comments) to see about getting a dc2dc converter that is large enough to handle slide out surge.

After I get the new fridge installed (over the weekend, fingers crossed), I'll do some testing to see where the system capacity stands and if any further changes need to be made.

Thanks for your replies!
 
Petenebraska said:
It's still hooked up to 12v, but only the circuit board is running on 12v. It senses if there is 120v and toggles between propane and ac when the unit is "on". If I turn off the 48v inverter, the fridge will just switch over to propane since it doesn't sense the 120v coming in anymore.

I'm going to talk with my installer (who has read this post string and has several constructive comments) to see about getting a dc2dc converter that is large enough to handle slide out surge.
Click to expand...

I can't wait.
 
Petnebraska - What's the Dometic fridge model number? There should be a name plate indicating 120Vac wattage inside the fridge door. How many watts does it consume? How old is the fridge? I like to understand your measurements.

​

 
Petenebraska said:
It's still hooked up to 12v, but only the circuit board is running on 12v. It senses if there is 120v and toggles between propane and ac when the unit is "on". If I turn off the 48v inverter, the fridge will just switch over to propane since it doesn't sense the 120v coming in anymore.

I'm going to talk with my installer (who has read this post string and has several constructive comments) to see about getting a dc2dc converter that is large enough to handle slide out surge.

After I get the new fridge installed (over the weekend, fingers crossed), I'll do some testing to see where the system capacity stands and if any further changes need to be made.

Thanks for your replies!
Click to expand...
Ahh so instead of switching the Fridge to Auto force it to stay on Propane only. If that's not an option you could use a smart plug and control it with your phone to power off the AC when off grid, then it wouldn't sense no AC power and switch to Propane.
 
Petenebraska said:
It's still hooked up to 12v, but only the circuit board is running on 12v. It senses if there is 120v and toggles between propane and ac when the unit is "on". If I turn off the 48v inverter, the fridge will just switch over to propane since it doesn't sense the 120v coming in anymore.

I'm going to talk with my installer (who has read this post string and has several constructive comments) to see about getting a dc2dc converter that is large enough to handle slide out surge.

After I get the new fridge installed (over the weekend, fingers crossed), I'll do some testing to see where the system capacity stands and if any further changes need to be made.

Thanks for your replies!
Click to expand...
If you do go with a Residential Fridge make sure you get one with the inverter compressor. I have a large 20 cubit ft that only uses 1.2 kwh per 24 hrs that is running off grid all the time. I can't remember the model, I will get that tonight.
 
ShanePowerHouse said:
If you do go with a Residential Fridge make sure you get one with the inverter compressor. I have a large 20 cubit ft that only uses 1.2 kwh per 24 hrs that is running off grid all the time. I can't remember the model, I will get that tonight.
Click to expand...
Thanks for the suggestion.

I bought this one: https://www.homedepot.com/p/LG-Elec...num-Silver-Counter-Depth-LTNC11131V/308085233

We had an LG with a linear compressor at our house before we sold and moved into the RV. My wife noticed a drop in our electric bill after we bought it. So, I'll give this a shot. Heck, if it's less than 1.21 Jigawatts, it'll be a step in the right direction!! :ROFLMAO:

Pete
 
chadjones99 said:
just reading the title: tell the kids to shut the door !
Click to expand...
Ha! I got all the kids off the payroll last spring! It's just me and my wife, now. And she's as paranoid, if not more so, than I am about saving and being efficient! If anyone is not closing the door, I'm sure it's not her or me!! :ROFLMAO::ROFLMAO::ROFLMAO:
 
Cal said:
Petnebraska - What's the Dometic fridge model number? There should be a name plate indicating 120Vac wattage inside the fridge door. How many watts does it consume? How old is the fridge? I like to understand your measurements.

​

Click to expand...
DM2862RFB Mfg date: 2018 1500 BTU/Hr (440w)

It runs for 3,000 hrs a day, culminating in 9 trillion Megawatts/12hrs or the equivalent of North America.... Anyone interested in a slightly used fridge?? :sneaky:
 
sunshine_eggo said:
Dang it... sounded more like there was gonna be a rumble... Oh well. :p
Click to expand...
Good Gawd from Bloomfield!? If you wanted to pick a fight, couldn't you have just dropped some Mom jokes or something?? :ROFLMAO:

I understand what you're both saying about the legacy 12v system, it's just so clunky! I hate clunk! :rolleyes:

My next step is getting the new fridge installed, then reevaluate. If that solves the battery-suck issue, I'll leave everything else alone.

Thanks!
 
LOL... I'm actually in AZ. Our parent company is in Bloomfield. All our internet traffic routes through CT. The VPN is exciting, especially if we have to access an AZ server, which I do all the time...

AZ client to CT, CT to AZ server, AZ server to CT, CT to AZ client.

Maddening.
 
Petenebraska said:
especially about removing the 12v batt and converter
Click to expand...
Petenebraska said:
next step is getting the new fridge installed, then reevaluate. If that solves the battery-suck issue, I'll leave everything else alone
Click to expand...

It’s less about removing the 12V system and/or battery than it is about disabling the power-sucking oem RV converter. Or anything else that is a nonproductive load like the RV fridge.
 
sunshine_eggo said:
LOL... I'm actually in AZ. Our parent company is in Bloomfield. All our internet traffic routes through CT. The VPN is exciting, especially if we have to access an AZ server, which I do all the time...

AZ client to CT, CT to AZ server, AZ server to CT, CT to AZ client.

Maddening.
Click to expand...
Sounds like my work. There is literally a data center next door, but all our stuff that we use is in the one halfway across the country. Because that makes sense...
 
12VoltInstalls said:
It’s less about removing the 12V system and/or battery than it is about disabling the power-sucking oem RV converter. Or anything else that is a nonproductive load like the RV fridge.
Click to expand...
Haven't read all 8 pages of this thread but I have one question. Is the converter drawing power from the onboard AC system? If so it ought to be disabled. It should only be drawing power from a shore power source, otherwise it is trying to charge the house batteries from ......THE HOUSE BATTERIES! That is guaranteed to drain them
 
  • Like
Reactions: Cal
littleharbor2 said:
Haven't read all 8 pages of this thread but I have one question. Is the converter drawing power from the onboard AC system? If so it ought to be disabled. It should only be drawing power from a shore power source, otherwise it is trying to charge the house batteries from ......THE HOUSE BATTERIES! That is guaranteed to drain them
Click to expand...
Well yes, that's my position too. But my installer and leggo my @sunshine_eggo make a reasonable argument for leaving the 12v legacy system in tact. Instead of removing that in exchange for a dc2dc converter, the 12v converter and 12v battery act as a buffer against slide and jack power surges where a dc2dc converter might fail. They're stating that the loss in efficiency is a small price to pay for the protection that it offers.

Sorry, eggo. Ever since reading your handle, I couldn't resist sneaking "leggo" in somewhere to the conversation.... :sneaky:
 
littleharbor2 said:
Haven't read all 8 pages of this thread but I have one question. Is the converter drawing power from the onboard AC system? If so it ought to be disabled. It should only be drawing power from a shore power source, otherwise it is trying to charge the house batteries from ......THE HOUSE BATTERIES! That is guaranteed to drain them
Click to expand...
Exactly my sentiments.

First off, an absorption fridge isn't meant to be run off a battery. It consumes way too much power. The fridge ac usage is meant for shore power. An absorption fridge operates sparingly off propane. That should be the primary energy source.

Per spec, the Dometic DM2862 consumes 440W ac power. No way should consumption be much higher than that. If it is, then something else is going on. Perhaps a measurement error or something like the converter being active and is causing an exorbitant load. But it's not the fridge. If the fridge was at room temperature prior to making the measurements then it will be at 100% duty cycle for a number of hours. Once it starts cycling power at perhaps 70% duty cycle, in 24 hours it should consume: 440W * 70% * 24 = 7.4 kWh. This data should have been known before starting the project!

How much power does the new fridge consume? Per spec, it has an energy consumption of 339. Not sure what that means. This article says a fridge like the new one consumes about 150 Ah in 24 hours. That's 1.8 kWh in 24 hours, or about 4 times more efficient on ac. It's still a lot of energy where long periods of clouds in the winter could run down the battery. That wouldn't be a problem with a propane fridge.
 
Cal said:
Exactly my sentiments.

First off, an absorption fridge isn't meant to be run off a battery. It consumes way too much power. The fridge ac usage is meant for shore power. An absorption fridge operates sparingly off propane. That should be the primary energy source.

Per spec, the Dometic DM2862 consumes 440W ac power. No way should consumption be much higher than that. If it is, then something else is going on. Perhaps a measurement error or something like the converter being active and is causing an exorbitant load. But it's not the fridge. If the fridge was at room temperature prior to making the measurements then it will be at 100% duty cycle for a number of hours. Once it starts cycling power at perhaps 70% duty cycle, in 24 hours it should consume: 440W * 70% * 24 = 7.4 kWh. This data should have been known before starting the project!

How much power does the new fridge consume? Per spec, it has an energy consumption of 339. Not sure what that means. This article says a fridge like the new one consumes about 150 Ah in 25 hours. That's 1.8 kWh in 24 hours, or about 4 times more efficient on ac. It's still a lot of energy where long periods of clouds in the winter could run down the battery. That wouldn't be a problem with a propane fridge.
Click to expand...
I'm picking up the new fridge today. I'll get the Dometic removed and the LG installed over the weekend, weather permitting. (I'm surprised at how much it ACTUALLY rains in S Texas?! Everyone says they're in a drought, but we either brought the weather with us from Idaho, or Texans don't know the definition of "drought"?! :LOL: )

I'll post back after installation and new measurements. I'm going to start here with fridge replacement. If the system is still too inefficient, I'll move on to 12v system (original 12v battery and converter) exchange for a 48v dc to 12v dc converter.
 
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
491
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