Refrigerator powered by inverter while driving

IrishSettler

I pull a used 2017 T@B 320s Teardrop.
I use 3 interstate 84 amp deep cycle batteries connected in parallel. The batteries drain very quickly when cooling the refrigerator while I am driving. Recently I purchased a 3,000 watt inverter to power my microwave or air conditioner while boon-docking. 

I read that higher voltage results in lower amperage use. If that is correct I should use fewer amps to operate the refrigerator at 110 volts instead of 12 volts, thus extending the battery life. 

Am I correct?

AnOldUR

Does your 2017 still have the 3-way fridge? If so, it's an antiquated electric hog no matter which way you power it on electric. There's a lose in efficiency using an inverter to go from 12V to 120V. That would seem to make it a bad option to use the inverter to power your fridge at 120V.

Your three 84Ah deep cycle batteries only give you about 126Ah of usable power. Your microwave and especially the AC will deplete that in no time if you power them with an inverter.

I'd suggest upping you battery capacity (LiFePO4) and think about moving to a 12V compressor type fridge.

MuttonChops

Short Answer:   Going to 120V mode via an inverter will not stop your battery drain.

Long Answer:
While the current demand of the Fridge does change based on the available voltage the actual Watts required remains nearly the same and it is the wattage that is power.

Running Fridge via Battery-2-Inverter might extend the battery bank life some but there are several variables to consider. A few:

1.  For wet-cell battery only 40% (some say 50%) of total Amp-Hr Capacity can be safety used.
     So let's say your 250AHr bank has ~ 100AHr to use then the battery bank is dead.

2.   Inverters are not 100% efficient.  The very best (expensive) are around 95%

3.   When the Fridge is in 12VDC Mode the heaters are on all the time.

4.   When the Fridge is in 120VAC Mode the heaters are Thermostat Controlled.
      What percentage of time the heaters are on will vary over a wide range depending on
      how it is loaded, what is in it, and the ambient temperature.

For the example in the following diagram I used a 100AHr bank and ignored the few amps (trickle charge) provided by the 7-Pin +12V connection.  Battery Life is about the same on 12VDC or Inverter for 120VAC.

Marceline

I'm pretty sure that you have a 3-way fridge. This fridge uses a substantial amount of power when operating on electricity rather than propane. If you need to run the fridge while driving, installing a DC-DC charger to draw more power from your tow vehicle might be a better solution. 

Cherokee

I have a 2019 T@B 320with a 3-way. While driving, the alternator in my Truck or my Jeep both provide enough power to operate the refrigerator when driving. Throwing Sparky into propane mode while Boondocking will cool food while consuming very little fuel. I stay out for days at a time with only 95 watts of solar. While those with electric refrigerators require 4 times as much solar     

IrishSettler

Thanks to everyone!
your information is very helpful. I will stick to the original refrigerator system until I save enough money for a more up to date model.
safe camping to all.

ColleenD2

I thought the camper had to remain level to be run the refrigerator. I don't really understand how people can drive with it turned on then. Can someone please explain?

AnOldUR

Cherokee said:

I stay out for days at a time with only 95 watts of solar. While those with electric refrigerators require 4 times as much solar.    

"Require" is hopefully not what you meant. You can justify your personal desire to continue using a 3-way fridge, but stating that it takes nearly 400W of solar to dry camp is at best, an exaggeration. With moderate amounts of sun, we find our batteries are charged by the end of the day using a 200W suitcase. Under these conditions, we can stay out indefinitely using our 12V fridge, television, radio, lights and recharging other devices.

AI disagrees also    ...
 

RTWCTS

@IrishSettler

In theory the concept of fewer amps with higher voltage is mathematically correct (Power=VoltagexAmps). However you'll use quite a few electrons converting from your 12V source to 120V with an inverter.  So, not really effective.

Back when we had a 320 with the 3-way fridge, I added 200W of solar panels just behind the roof vent. We found that the roughly 10A of power they provided would mitigate the excessive draw of the fridge running on 12V while driving. When we got to camp we would switch over to gas. Hope this helps.

Cherokee

AnOldUR said:

Cherokee said:

I stay out for days at a time with only 95 watts of solar. While those with electric refrigerators require 4 times as much solar.    

"Require" is hopefully not what you meant. You can justify your personal desire to continue using a 3-way fridge, but stating that it takes nearly 400W of solar to dry camp is at best, an exaggeration. With moderate amounts of sun, we find our batteries are charged by the end of the day using a 200W suitcase. Under these conditions, we can stay out indefinitely using our 12V fridge, television, radio, lights and recharging other devices.

AI disagrees also    ...
 

I go by the experience of people who actually Boondock their T@B. This is someone actually Booondocking with an electric refrigerator : https://www.youtube.com/watch?v=OujY7L7a1vA

RTWCTS

Cherokee said:

I go by the experience of people who actually Boondock their T@B. 

@AnOldUR does "actually Boondock". We were camped near him (them) in Ohio last June, where they boondocked for a week at uCamp.
As far as the 12V fridges go, we regularly boondock in our T@B 400 for days on end with 185W of solar and never run out of electricity (as long as we can get sun to the rooftop).

Marceline

Cherokee said:

I go by the experience of people who actually Boondock their T@B. This is someone actually Booondocking with an electric refrigerator : https://www.youtube.com/watch?v=OujY7L7a1vA

Has it occurred to you that there are many people on this forum who *actually* have a lot of experience boondocking with a 2way fridge?

I've been boondocking with my T@B CS-S (2way fridge) since 2017. My current setup is 160w solar panel and 90aH LionEnergy LiFePO4 battery. Last summer I managed to keep the fridge running in 100+deg temps for 4 days and the battery was still half charged when I packed up.

Of course the 2way fridge consumes more power (I budget 35-40aH per day for power consumption) than the 3way on propane mode. But when you're running the 2way  fridge while traveling, it consumes much less power than the 3way fridge on DC power (constant 10amps - which is topic that launched this thread).

AnOldUR

Cherokee said:
I go by the experience of people who actually Boondock their T@B. This is someone actually Booondocking with an electric refrigerator : https://www.youtube.com/watch?v=OujY7L7a1vA

Interesting video, but I would take a lot of its information with a grain of salt. Camping in a T@B is a continuing learning experience for all of us.

My takeaway concerning solar is that they have a single AGM battery. That would probably be a 75Ah or 100AH battery, of which only half is often considered usable. Regardless of their solar setup, they don't have enough battery capacity to store the energy that they take in during the day.

With the money they spent on their power station they could have doubled or even quadrupled their battery capacity with LiFePO4. The benefit being that they would not have the worry of spoiled food from monkeying with the temperature setting in their fridge. With our 12V compressor fridge we can set it to 37 degrees and forget it. No issues with variations due to outside temperature that come with an absorption fridge.

Cherokee

AnOldUR said:

Cherokee said:
I go by the experience of people who actually Boondock their T@B. This is someone actually Booondocking with an electric refrigerator : https://www.youtube.com/watch?v=OujY7L7a1vA

Interesting video, but I would take a lot of its information with a grain of salt. Camping in a T@B is a continuing learning experience for all of us.

My takeaway concerning solar is that they have a single AGM battery. That would probably be a 75Ah or 100AH battery, of which only half is often considered usable. Regardless of their solar setup, they don't have enough battery capacity to store the energy that they take in during the day.

With the money they spent on their power station they could have doubled or even quadrupled their battery capacity with LiFePO4. The benefit being that they would not having the worry of spoiled food from monkeying with the temperature setting in their fridge. With our 12V compressor fridge we can set it to 37 degrees and forget it. No issues with variations due to outside temperature that come with an absorption fridge.

AnOldUR said:

Cherokee said:
I go by the experience of people who actually Boondock their T@B. This is someone actually Booondocking with an electric refrigerator : https://www.youtube.com/watch?v=OujY7L7a1vA

Interesting video, but I would take a lot of its information with a grain of salt. Camping in a T@B is a continuing learning experience for all of us.

My takeaway concerning solar is that they have a single AGM battery. That would probably be a 75Ah or 100AH battery, of which only half is often considered usable. Regardless of their solar setup, they don't have enough battery capacity to store the energy that they take in during the day.

With the money they spent on their power station they could have doubled or even quadrupled their battery capacity with LiFePO4. The benefit being that they would not having the worry of spoiled food from monkeying with the temperature setting in their fridge. With our 12V compressor fridge we can set it to 37 degrees and forget it. No issues with variations due to outside temperature that come with an absorption fridge.

Yes - "your mileage may vary"  but indeed, we are in agreement that more electric energy is consumed with a two way when Boondocking - which necessitates more solar and more storage. The old 3-way runs on very little propane. Sparky can be temperamental, but while being towed, it vents its heat to the outside of the T@B. NOT inside the trailer where NuCamp currently vents its refrigerators. Neither option is perfect. One of the best installations I've seen on this site, an owner replaced his irreplaceable 3-way with an electric ref with its condenser on the same side as his old unit. He then built ducts and added a fan to utilize his old vents. We get by with two AGM 6v Golf Cart batteries wired in series. With California's abundant sunshine, a 95 watt solar panel is all we need. The newer trailers from most manufactures come with lithium batteries. With the cost of full connections at an RV site, Boondocking makes these trailers far more economical!            

SLJ

Cherokee said:

I go by the experience of people who actually Boondock their T@B. This is someone actually Booondocking with an electric refrigerator : https://www.youtube.com/watch?v=OujY7L7a1vA

We boondock. That's pretty much all we do. We have the same T@B as the video. We've have had propane fridges for many years. For the past three years w/two 100ah lithium batteries and a 200w portable panel we are able to go indefinitely with our 12 volt fridge. Last year with ten straight days of rain and total cloud cover the lowest our Lithium batteries ever went down to was 48%. My 12 volt fridge goes down to the high 30's in about an hour at start up and is able to stay below 40 even in high heat. None of my propane fridges would do that. Those that think propane is the only way to boondock have most likely never used a 12v fridge with a solar set up. I never have to worry about propane level or battery level anymore. We're never going back to propane.

Marceline

Cherokee said:

Yes - "your mileage may vary"  but indeed, we are in agreement that more electric energy is consumed with a two way when Boondocking - which necessitates more solar and more storage. The old 3-way runs on very little propane. Sparky can be temperamental, but while being towed, it vents its heat to the outside of the T@B. NOT inside the trailer where NuCamp currently vents its refrigerators. Neither option is perfect. One of the best installations I've seen on this site, an owner replaced his irreplaceable 3-way with an electric ref with its condenser on the same side as his old unit. He then built ducts and added a fan to utilize his old vents. We get by with two AGM 6v Golf Cart batteries wired in series. With California's abundant sunshine, a 95 watt solar panel is all we need. The newer trailers from most manufactures come with lithium batteries. With the cost of full connections at an RV site, Boondocking makes these trailers far more economical!            

If you're running your refrigerator on propane while driving, that would explain why you're not encountering the same battery issues as the OP @IrishSettler

However, I hope you're aware that there is some controversy about running your fridge on propane while driving, and I would hope at the very least you're turning it off before entering any gas station.

https://shunauto.com/article/do-any-states-allow-propane-to-be-on-a-camper

Cherokee

Marceline said:

Cherokee said:

Yes - "your mileage may vary"  but indeed, we are in agreement that more electric energy is consumed with a two way when Boondocking - which necessitates more solar and more storage. The old 3-way runs on very little propane. Sparky can be temperamental, but while being towed, it vents its heat to the outside of the T@B. NOT inside the trailer where NuCamp currently vents its refrigerators. Neither option is perfect. One of the best installations I've seen on this site, an owner replaced his irreplaceable 3-way with an electric ref with its condenser on the same side as his old unit. He then built ducts and added a fan to utilize his old vents. We get by with two AGM 6v Golf Cart batteries wired in series. With California's abundant sunshine, a 95 watt solar panel is all we need. The newer trailers from most manufactures come with lithium batteries. With the cost of full connections at an RV site, Boondocking makes these trailers far more economical!            

If you're running your refrigerator on propane while driving, that would explain why you're not encountering the same battery issues as the OP @IrishSettler

However, I hope you're aware that there is some controversy about running your fridge on propane while driving, and I would hope at the very least you're turning it over before entering any gas station.

https://shunauto.com/article/do-any-states-allow-propane-to-be-on-a-camper

NO we tow with the propane turned off for safety reasons. Most modern trucks produce enough power from their alternators to easily power the 3-way in our T@B while driving  

Marceline

Cherokee said:

NO we tow with the propane turned off for safety reasons. Most modern trucks produce enough power from their alternators to easily power the 3-way in our T@B while driving  

This isn't true.  A lot of modern "smart" alternators will not output 10a to the charge line. This is probably the reason that @IrishSettler is having issues.
 

Cherokee

SLJ said:

Cherokee said:

I go by the experience of people who actually Boondock their T@B. This is someone actually Booondocking with an electric refrigerator : https://www.youtube.com/watch?v=OujY7L7a1vA

We boondock. That's pretty much all we do. We have the same T@B as the video. We've have had propane fridges for many years. For the past three years w/two 100ah lithium batteries and a 200w portable panel we are able to go indefinitely with our 12 volt fridge. Last year with ten straight days of rain and total cloud cover the lowest our Lithium batteries ever went down to was 48%. My 12 volt fridge goes down to the high 30's in about an hour at start up and is able to stay below 40 even in high heat. None of my propane fridges would do that. Those that think propane is the only way to boondock have most likely never used a 12v fridge with a solar set up. I never have to worry about propane level or battery level anymore. We're never going back to propane.

Good for you - All I said was that it took more battery storage and more solar to keep a 2-way going while Boondocking. Your statement collaborates with that fact. We tend to go to the mountains in summer and the desert in winter. So we don't often reach extremums you site. You may not miss sparky, but I'd bet you do miss that lovely wood ceiling.     

pthomas745

Most all the 2 way fridges use roughly the same amount of power, anywhere from 25-40 amp hours a day.  I have a small portable Alpicool fridge that uses...45 watts when running, and since it is fairly small, it works out to about the 24-30 amp hours a day.  My last two trips out, I've been running that fridge using a small 50 amp hour battery.  Early in the summer, using a 100 watt panel, there were no issues at all keeping the 50 amp hour lithium charged and the fridge running. 

I recently upgraded that 2014 100 watt panel to a 200 watt suitcase, and just came back from 7 days in the desert, and the increased solar input had my 50 amp hour battery and my 100 amp hour trailer battery back to a full charge easily each day.

We have known for a long while about the real limitations of the 2 way fridge: the "stock" 80 amp hour batteries installed in 320s several years ago were simply inadequate.  (This is where you would need 400 watts of portable solar!) On top of the "too small battery" the problem is the solar "on the roof".  As cool as "solar on the roof" is, there is no substitute when the trailer is parked for having a portable solar panel that can be optimized for solar charging. 200 watts would appear to be the sweet spot for a 100 amp hour lithium battery with a 2 way fridge.

I have struggled a bit with my 3 way fridge on propane the last two years: I can make it work, then it doesn't, then...it still doesn't.  I will take it out, change to a 2 way fridge, and never regret it.

SLJ

Cherokee said:

SLJ said:

Cherokee said:

I go by the experience of people who actually Boondock their T@B. This is someone actually Booondocking with an electric refrigerator : https://www.youtube.com/watch?v=OujY7L7a1vA

Good for you - All I said was that it took more battery storage and more solar to keep a 2-way going while Boondocking. Your statement collaborates with that fact. We tend to go to the mountains in summer and the desert in winter. So we don't often reach extremums you site. You may not miss sparky, but I'd bet you do miss that lovely wood ceiling.     

You stated you go by the experience of people who actually Boondock. Here ya go. My 12V fridge draws 2.5A when the compressors running which is maybe 60% of the time when it's warm. Less at night. That's ~1.5Amps/hour. I can go for 4 or 5 days with absolutely no recharging at all. When towing, my TV supplies 8 amps, more than enough to charge batteries and run the fridge at the same time. Propane's old technology even for boondocking.

AnOldUR

I compare this discussion to one about ICE and electric vehicles. I'll continue to use my old Jeep for as long as it is practical, but would never try to defend it as a practical or sustainable means of transportation. Vehicles using alternative sources of energy have not reached the point of competing with ICE vehicles in many situations (towing, range ...), but are getting closer all the time. Trying to justify gas as a source for transportation energy in the future is just being stubborn.

The 3-way vs 12V refrigerator argument has the same flaws except for the fact that the technology and cost has made a 12V compressor fridge the only logical choice. I don't think anyone here would argue against someone continuing to use a functional absorption fridge if they are satisfied with it, but I don't understand any other attempt to justify it. I know my Jeep is a dinosaur and far from the perfect tow vehicle. I would never try to convince anyone that it's anything other than a personal choice.

bjn2

It's so easy to see the world through one pair of sunglasses. For our boondocking, we're often more concerned with preserving propane for heating than we are with keeping the fridge cool. But we also camp in hot conditions that may or may not provide good solar exposure. So I'm building in as much versatility as I can with lithium and solar. I will be adding DC to DC so we have the option to charge from the TV.

One observation I'd add is that I bet very few folks using heavy lead-acid battery banks have added low voltage protection to their setup. Overdischarging would be really easy without that protection, and nobody wants to spent their camping time monitoring battery voltage.

Cherokee

For what it's worth, I believe what one dose with their trailer is far more important then this continued argument. Fortunately, where I pull my T@B the issue is mute:      only a few can follow me 

pthomas745

@bjn2 The 2 way fridges and the Alde both have their own "low voltage" disconnects when they sense a low battery voltage.  This, of course, does not save the lead acid battery from dropping to a much lower level with just the "parasitic" or other 12V loads of the trailer.

ColleenD2

CAN SOMEONE PLEASE EXPLAIN HOW YOU CAN DRIVE WITH THE FRIDGE ON WHEN ITS SUPPOSED TO BE LEVEL WHEN YOU RUN IT? 

According to Norcold recommendations, an RV fridge, specifically a "Norcold" fridge, should be level within a range of 3 degrees off level side-to-side and 6 degrees off level front-to-back for optimal operation; meaning it doesn't need to be perfectly level but should be close to it to function properly. An unlevel fridge can disrupt the flow of the ammonia cooling system, potentially causing damage to the appliance by creating blockages or ammonia crystal buildup due to improper gravity-based circulation.

@MuttonChops or @Cherokee can you help?

Thanks. 😊 

Cherokee

ColleenD2 said:

CAN SOMEONE PLEASE EXPLAIN HOW YOU CAN DRIVE WITH THE FRIDGE ON WHEN ITS SUPPOSED TO BE LEVEL WHEN YOU RUN IT? 

According to Norcold recommendations, an RV fridge, specifically a "Norcold" fridge, should be level within a range of 3 degrees off level side-to-side and 6 degrees off level front-to-back for optimal operation; meaning it doesn't need to be perfectly level but should be close to it to function properly. An unlevel fridge can disrupt the flow of the ammonia cooling system, potentially causing damage to the appliance by creating blockages or ammonia crystal buildup due to improper gravity-based circulation.

@MuttonChops or @Cherokee can you help?

Thanks. 😊 

YES - Sparky likes to be close to level to run on Propane. Sparky is also sensitive to wind blowing through the lower vent on the pilot light.  However, it is a 3-way - so we run it on the 12v setting when towing. Most modern alternators produce more then enough power to run Sparky. It isn't safe to tow with the gas turned on in a T@B.   

Cherokee

Marceline said:

Cherokee said:

NO we tow with the propane turned off for safety reasons. Most modern trucks produce enough power from their alternators to easily power the 3-way in our T@B while driving  

This isn't true.  A lot of modern "smart" alternators will not output 10a to the charge line. This is probably the reason that @IrishSettler is having issues.
 

Odd that I do not remember this "issue" coming up when NuCamp was placing 3-ways in T@B's. I've pulled mine all over this country and I've met a lot of different people traveling with 3-ways with several different TV's. My T@B has been pulled with: a '99 Jeep Cherokee, a 2016 Toyota 4-Runner, a 2018 Frontier SV , and a 2019 Frontier PRO4X; all of which had stock electrical systems.NONE of these had any problems supplying energy to run the 3-way on it's 12v setting. Mandy of NuCamp pulled her 320 with both a Grand Cherokee and a 4-Runner.  However, having the wrong gauge wire leading to a 7-way plug or a week alternator could be the real problem. A lot of power is expended when starting a TV. Alternators are sized to quickly replenish the battery's charge after starting - smart or otherwise. Ten amps isn't a lot of power, though it is more then the current 2-way draws, so why not make it an issue?