Refrigerator and battery drainage

[InterBlog]

On the subject of fridges, does anyone know why Airstream switched from a propane fridge to an "all electric"? Are there disadvantages to the propane models that I don't know about yet?

[Lily&Me]

Originally Posted by Protagonist

I never really considered an Airstream Interstate to be much of a boondocking vehicle, and the only times I expect to ever need to boondock in it is for the first night of a hurricane evacuation, or if I arrive at a WBCCI rally too late to be parked the same day and I have to spend the night in the "bullpen" until I can be parked in my campsite the next morning.

Honestly, if I really wanted to boondock, I'd still be a tent camper.

When you retire, Protag, and start roaming the country, you may change your mind on boondocking for a night or two in a spectacularly beautiful spot that has no amenities.

Extremes in temperatures prohibiting, there is something very freeing and liberating about pulling in somewhere to spend a night, knowing you have everything you need to be comfortable......right in your itty, bitty rig.

We have a flexibity the big rigs just don't have.


Maggie

[avanti]

Originally Posted by InterBlog

On the subject of fridges, does anyone know why Airstream switched from a propane fridge to an "all electric"? Are there disadvantages to the propane models that I don't know about yet?

The new "electric only" fridges are compressor units (like those used in homes). Propane units are "absorption" refrigerators, which have several disadvantages, including (a) very slow initial cooling; (b) erratic performance; (c) relatively large power consumption when used in 12VDC mode; and (d) poor performance when not level.

None of these things are true of modern compressor fridges such as the NovaKool. All else being equal, a compressor unit will consume about 1/3 the power of an absorption fridge when run on 12VDC. The NovaKool is great. They are rapidly taking over the industry.

[peteinlongbe]

Originally Posted by avanti

The new "electric only" fridges are compressor units (like those used in homes). Propane units are "absorption" refrigerators, which have several disadvantages, including (a) very slow initial cooling; (b) erratic performance; (c) relatively large power consumption when used in 12VDC mode; and (d) poor performance when not level.

None of these things are true of modern compressor fridges such as the NovaKool. All else being equal, a compressor unit will consume about 1/3 the power of an absorption fridge when run on 12VDC. The NovaKool is great. They are rapidly taking over the industry.

I've had both types of refrigerators in my previous coaches, and since I do a fair share of boondocking, I far prefer the gas absorption type. Yes, the initial cooling is slower, but all it takes is a bit more planning ahead before stocking it. The cooling is somewhat affected by ambient air temperature, but not so much that is a problem. I could run for weeks on propane, using negligible 12V for the controller. The 12V cooling mode is only intended for use while driving, so this cannot really be compared to the performance of a 12V compressor unit as there is no battery drain issue when driving and the mode is not used when stationary. I've never had a level issue, as the coach is relatively level while driving and always leveled at campsite.

This is the one issue I have with the later Interstates - no option for absorption refrigerators. I do realize these newer 12V compressor units are quite efficient, but they still use considerably more power than an absorbtion unit running on propane. My question would be - how long can you run a NovaKool before you need to recharge the house batteries?

[Protagonist]

Originally Posted by peteinlongbe

This is the one issue I have with the later Interstates - no option for absorption refrigerators. I do realize these newer 12V compressor units are quite efficient, but they still use considerably more power than an absorbtion unit running on propane. My question would be - how long can you run a NovaKool before you need to recharge the house batteries?

Never ran one that long just on the house batteries. Before a trip, I cool down the fridge in 12v mode, and the dinky 50w solar panel on the roof is just about able to keep up with the demand except in the hottest part of mid-summer (assuming no other appliances are turned on). Given that the fridge is on 24 hours and the solar panel is only charging the house batteries during daylight hours…

[73shark]

That's been my experience with the refrigerator also. With sunlit days, the solar panel can keep up with the load without any other loads.

[peteinlongbe]

Originally Posted by 73shark

That's been my experience with the refrigerator also. With sunlit days, the solar panel can keep up with the load without any other loads.

Nice to know. So, enhancing the factory solar system up to about 150-200 watts of panels, there should be no issue keeping up. I'm also guessing that in colder weather, the refrigerator compressor won't be cycling as often, allowing the use of the furnace without too much effect on the batteries.

I have power management down to a science on my current coach with propane refrigeration and no solar system. So, just trying to understand how I can use an Interstate as effectively.

[Redd]

I have the 2017 AI Grand Tour with the split refrigerator (refrig on top and separate freezer section in a drawer on the bottom). I plug into shore power at home and my batteries show over 13 volts. I prechill my freezer for more than 24 hours. Then when I take off and get to my boondocking destination I find that my battery level is down to 60% or 12 volts after only 16 hours. I haven't used really any other electricity for water heater, etc. In other words, except for the freezer my power consumption has been minimal. I have one 100 watt solar panel and it's in a sunny area.
Does is sound right to you that I'd get only 16 hours off the batteries with mostly just my freezer consuming power? Would it be most cost effective to add two more solar panels or two more batteries? I don't boondock a lot but occasionally a three-day weekend maybe twice a year.

[TayaraTravel]

Originally Posted by Redd

I have the 2017 AI Grand Tour with the split refrigerator ...
Does is sound right to you that I'd get only 16 hours off the batteries with mostly just my freezer consuming power? Would it be most cost effective to add two more solar panels or two more batteries? I don't boondock a lot but occasionally a three-day weekend maybe twice a year.

We have similar experience. If we are fully charged in late afternoon, from either driving or generator, we have a bit over 50% the next morning (12.1-12.3v). Only running refrigerator/freezer. We also are careful to turn off the LPG switch to eliminate solenoid current. We have 4 12v batteries (320AH total) and 300 watts of solar. Even with this, we can't stay unplugged and undriven more than 24 hours without supplementing with generator.

[rowiebowie]

Originally Posted by Redd

I have the 2017 AI Grand Tour with the split refrigerator (refrig on top and separate freezer section in a drawer on the bottom). I plug into shore power at home and my batteries show over 13 volts. I prechill my freezer for more than 24 hours. Then when I take off and get to my boondocking destination I find that my battery level is down to 60% or 12 volts after only 16 hours. I haven't used really any other electricity for water heater, etc. In other words, except for the freezer my power consumption has been minimal. I have one 100 watt solar panel and it's in a sunny area.
Does is sound right to you that I'd get only 16 hours off the batteries with mostly just my freezer consuming power? Would it be most cost effective to add two more solar panels or two more batteries? I don't boondock a lot but occasionally a three-day weekend maybe twice a year.

Originally Posted by TayaraTravel

We have similar experience. If we are fully charged in late afternoon, from either driving or generator, we have a bit over 50% the next morning (12.1-12.3v). Only running refrigerator/freezer. We also are careful to turn off the LPG switch to eliminate solenoid current. We have 4 12v batteries (320AH total) and 300 watts of solar. Even with this, we can't stay unplugged and undriven more than 24 hours without supplementing with generator.

It's curious to see others having problems or worrying about their ability to run their compressor fridge. I must start by saying I used the resources of this forum to eliminate parasitic drains. In addition, we use a 12v TV so we do not need to engage the inverter when dry camping and have not had any issues with batteries running whatever we needed for 12-15 hours overnight. We did not find the fridge, furnace, or LP solenoid to be a significant battery drain.

Our '2012 Avenue has just two lead-acid wet cell (spelled "cheapo") Sam's Club batteries. We do driving trips and never stay more than a single night in one location. Usually hit camp about 6pm and broke camp about 9am the next morning, on average.

As long as we were only doing a single overnight dry camp and our batteries were fully charged from driving, we were fine. We dry camped 9 of 13 nights on our trip in May from the Texas coast to Yellowstone. We were able to run our lights & 12volt tv/dvd combo from 6pm-10pm, run either our Maxxfan or furnace overnight (depending on temperature), and never woke up to less than 70-75% battery capacity. And we also had the compressor fridge running 24/7. We did not have a need to use the inverter our entire trip, so that additional battery drain was not an issue.

We purchased the van in Oct. '2017 with new batteries (dated 07/2017). Yet they were not keeping charge an running down after about a week if left sitting in the driveway even with everything off. New did not mean good in our case, or someone had already damaged them at the dealer lot.

Don't know if we just got lucky, but something doesn't seem right if you can't go more than 24 hours given a large battery bank.

[wachuko]

Originally Posted by TayaraTravel

We have similar experience. If we are fully charged in late afternoon, from either driving or generator, we have a bit over 50% the next morning (12.1-12.3v). Only running refrigerator/freezer. We also are careful to turn off the LPG switch to eliminate solenoid current. We have 4 12v batteries (320AH total) and 300 watts of solar. Even with this, we can't stay unplugged and undriven more than 24 hours without supplementing with generator.

That does not sound right... with the four batteries fully charged, you should be able to be fine in the morning with only those loads...

Were the batteries checked for condition? The ones that were already in there before you added the additional two new ones?

[TayaraTravel]

Originally Posted by wachuko

That does not sound right... with the four batteries fully charged, you should be able to be fine in the morning with only those loads...

Were the batteries checked for condition? The ones that were already in there before you added the additional two new ones?

I must have given the wrong impression. We CAN go one overnight if we start late afternoon with 100% State of Charge. In the morning we will see 12.1-12.3v, which I understand to be something over 50% SOC. And we are running refer/freezer, Max fan, lights, other moderate consumers.

What we can't do is stay in one spot (no driving) without hookups for two nights in a row, without using either generator or running the engine a bit. The solar alone (300w installed) even with good solar exposure doesn't keep up for more than 24 hours. It keeps us charged during the idle day, but enters the second evening at less than 100% SOC and we are falling under 12.0v the next morning.

So I'm reasonably OK with our present capability. I would like a larger margin of safety, so at some point in the future I will probably go to the 6v AGM batteries, giving a total of 440AH installed versus present 320AH.

As far as battery condition, I've never had them checked. Two of the 12v AGMs were factory installed (2017) but were possibly (pure speculation on my part) damaged during a long service holdover at a bad local dealer last year. The other two were added new as an upgrade by another service provider.

[rowiebowie]

Originally Posted by TayaraTravel

I must have given the wrong impression. We CAN go one overnight if we start late afternoon with 100% State of Charge. In the morning we will see 12.1-12.3v, which I understand to be something over 50% SOC. And we are running refer/freezer, Max fan, lights, other moderate consumers.

What we can't do is stay in one spot (no driving) without hookups for two nights in a row, without using either generator or running the engine a bit. The solar alone (300w installed) even with good solar exposure doesn't keep up for more than 24 hours. It keeps us charged during the idle day, but enters the second evening at less than 100% SOC and we are falling under 12.0v the next morning.

So I'm reasonably OK with our present capability. I would like a larger margin of safety, so at some point in the future I will probably go to the 6v AGM batteries, giving a total of 440AH installed versus present 320AH.

As far as battery condition, I've never had them checked. Two of the 12v AGMs were factory installed (2017) but were possibly (pure speculation on my part) damaged during a long service holdover at a bad local dealer last year. The other two were added new as an upgrade by another service provider.

I agree with wachuko to have your batteries checked. You shouldn't be at or near 50% overnight with the amp hours you presently have.

[Boxster1971]

TAYARATRAVEL - With 300W solar and 320AH batteries you should be able to go several days if you are just running the frig/freezer.

Do you have a separate cutoff switch for the inverter? Or that nasty solenoid setup?

What solar controller do you have? If it is the original piece of junk installed by Airstream that is a big part of your problem. Also you might have miss-matched batteries based on what you said about the originals possibly being damaged.

[rowiebowie]

With 1/2 the battery capacity and original Tripplite inverter/charger plus the measly 20W factory solar and Atkinson controller We did ok overnight. That should say something is wrong right there. Need to check batteries and/or for some other power drain.

At the time & places I traveled back in May, it was cool (even cold in some places) so our Novacool 3.1 cf fridge was not always working hard. But I noticed no appreciable difference when temperatures rose back into the high 80's. Still, in every case it was a lot cooler than now.

[Boxster1971]

Originally Posted by Redd

I have the 2017 AI Grand Tour with the split refrigerator (refrig on top and separate freezer section in a drawer on the bottom). I plug into shore power at home and my batteries show over 13 volts. I prechill my freezer for more than 24 hours. Then when I take off and get to my boondocking destination I find that my battery level is down to 60% or 12 volts after only 16 hours. I haven't used really any other electricity for water heater, etc. In other words, except for the freezer my power consumption has been minimal. I have one 100 watt solar panel and it's in a sunny area.

Does is sound right to you that I'd get only 16 hours off the batteries with mostly just my freezer consuming power? Would it be most cost effective to add two more solar panels or two more batteries? I don't boondock a lot but occasionally a three-day weekend maybe twice a year.

You have discovered the main weakness of your GT model. The larger frig/freezer combined with only two modest batteries and only a single 100W solar panel. These weaknesses are why the newest 2019 Interstate GT's will have four batteries and 300W solar systems.

Unfortunately Airstream is still not upgrading the solar controller to a better unit. The standard Atkinson PWM controller they are using is just not a good solution for optimal solar charging.

Adding both more solar and batteries would be best. If you don't want to go that far - then more solar would be my first choice, along with a better quality MPPT solar charge controller. That what I did on my 2013 Interstate. First I replaced the little 50W solar panel with two 100W panels and a good quality BlueSky MPPT solar controller. That gave me reasonable capability to run the frig for several days. Then I went the next step adding two more 100W panels and changed batteries to four 6V AGMs under the van. I also upgraded the Inverter/Charger to a 2000W unit. Now I can run the microwave off batteries and can go a week if I get sunshine and conserve electrical use.

All the best,

[gmillerok1]

For what it's worth for anyone following this thread, units like my 2011 Interstate that have the smaller fridge draws about 2.8 amps when the compressor runs based on the Victron Battery monitor. The parasitic drain of the inverter is .6 amps. So, 3.4 amps just running with no other loads.

[Alex AVI]

Originally Posted by Boxster1971

Unfortunately Airstream is still not upgrading the solar controller to a better unit. The standard Atkinson PWM controller they are using is just not a good solution for optimal solar charging.

MIKE - I was looking into the 2019 Classics brochure and found out they are now being equipped with ZAMP panel and Victron MPPT charge controller. So maybe it will eventually trickle into the 2019 AI ? Or does it just mean the AI will always be in the low end of totem pole as far as getting better upgraded equipment and may never get them

[TayaraTravel]

Originally Posted by Boxster1971

TAYARATRAVEL - With 300W solar and 320AH batteries you should be able to go several days if you are just running the frig/freezer.

Do you have a separate cutoff switch for the inverter? Or that nasty solenoid setup?

What solar controller do you have? If it is the original piece of junk installed by Airstream that is a big part of your problem. Also you might have miss-matched batteries based on what you said about the originals possibly being damaged.

I don't use the inverter part of the Magnum at all. It is shut off. (We don't use TV or other A/C consumers when on battery or solar power.) We installed an interior LPG switch, and always cut off the LPG unless actually cooking or heating water. We have the Victron MPPT solar controller. I do the "long push" on the Fusion.

I haven't tested the batteries, so it's possible we either got a bad original set from Airstream factory, or our initial weeks-long dealer service visit allowed them to deplete through neglect.

My estimate of State of Charge is coming from the voltage reported by the Magnum and confirmed by the Victron bluetooth app. I'm assuming that 12.0 or so volts means I'm down to 50% SOC. I realize this is not resting voltage, so maybe I'm underestimating SOC.

How much current does the Nova Kool frige/freezer draw? I have separate units (not sure about the model number). It's a 2017 van.

[Boxster1971]

Originally Posted by Alex AVI

MIKE - I was looking into the 2019 Classics brochure and found out they are now being equipped with ZAMP panel and Victron MPPT charge controller. So maybe it will eventually trickle into the 2019 AI ? Or does it just mean the AI will always be in the low end of totem pole as far as getting better upgraded equipment and may never get them

ALEX - I hope they do it, that would be a great step forward for Interstates.