Solar Show and Tell

[blacklab]

AirMiles,

Darn, I'm really sorry to hear of your assessment of the new 3-way Refrig. And, unfortunately, unless AS decides differently, we'd be stuck with it if we go with a GT 27.

To clarify/confirm, you are finding that even on propane it does not cool as well as the 2-way in your FC?

And also suffers the need to be absolutely level when running on propane?

This should be brought to the attention of AS. Presumably they see this as an upgrade, but, at least based on your experience, it seems the opposite.

Cheers,
Bryan

[AirMiles]

Originally Posted by blacklab

AirMiles,

Darn, I'm really sorry to hear of your assessment of the new 3-way Refrig. And, [CODE]unfortunately, unless AS decides differently, we'd be stuck with it if we go with a GT 27.

To clarify/confirm, you are finding that even on propane it does not cool as well as the 2-way in your FC?

And also suffers the need to be absolutely level when running on propane?

This should be brought to the attention of AS. Presumably they see this as an upgrade, but, at least based on your experience, it seems the opposite.

Cheers,
Bryan

Yes even on propane it runs constantly to keep the refrigerator cold. It barely can freeze two ice cube trays per 24 hour period. It works the same on DC, propane or electric.

I never needed to keep my 2017 FC25FB level for that refrigerator to work perfectly and I never had to worry about it. It just worked. My new three-way fridge needs constant monitoring. Needs me to level and re-level the Airstream because the refrigerator is not cooling properly. Here’s a picture of how I monitor it. I use a four zone electronic thermometer. Big zone is inside Airstream, second zone is outside, third zone is freezer and fourth zone is the refrigerator.

I know those temperatures look pretty good right now. 10 degrees in freezer and 34 degrees in refrigerator. That’s because the refrigerator is nearly perfectly level. See picture of level and where I level from bottom of refrigerator. The reason we are not perfectly level is because we are traveling and stopped at a Sams Club for the night. I moved several times to get this level. With the old Airstream, I would have just found a kind of level spot and not worried about being level.

PS, Airstream Factory adjusted my refrigerator to improve its performance by moving the temperature sensor in the refrigerator to the highest point possible. Before doing that, I barely could keep the refrigerator below 50 degrees even with the AC on 75 degrees in the Airstream.

[blacklab]

AirMiles,

Darn, that's crazy.

Not surprising I guess, but the Sales person at our local AS dealership is touting this new 3-Way as a big upgrade. And, also saying that it will run on DC "all day" and how great it is that you can run it on DC while towing.

Sounds to me like AS needs to seriously reconsider using this 3-way Refrig. The hassle you describe is crazy.

Cheers,
Bryan

[nryn]

AirMiles,

I wonder if something is wrong with your fridge?

I’ve had two fridges in my GT. The first one died spectacularly about a week into my trip to Alaska. Airstream managed to arrange a replacement along the way and I got a new one installed about 5 weeks into the trip. The first one was behaving somewhat erratically before it kicked the bucket.

The new one worked exponentially better than the old one. I caught some salmon and had it filleted and packed then put in the freezer. It froze like a rock and stayed that way for weeks.

The fridge fluctuates a bit but doesn’t get over 40.5° and is usually around 34-35° (I have a thermometer in both the fridge and freezer compartments).

No issues at all with my fridge. I get that some people want their fridge colder for drinks and so forth but I’m very happy with the new fridge. I would be equally happy with a 2-way (and from what I gather it would have been easier to make work—if the board is shot on the 3-way you’re SOL).

[AirMiles]

Nyrn, sounds like my refrigerator is working about the same as yours. On its highest setting it will get 33 degrees in fridge and teens in freezer. I’m ok with this too. But mine needs to be perfectly level for this performance. Otherwise, the fridge can climb to the mid- 50s pretty quickly. For the first few days of this trip we could not get the fridge below 50 and the freezer much below 32 until I figured out how to level the Airstream so the fridge would work. I now level the Airstream so the bottom of the fridge is level. Then the fridge works. But it still struggles to make ice. It also cools back down slower when adding room temperature water or food to the refrigerator. It just seems like it has less cooling capabilities than the two-way fridge in my 2017 FC25FB.

[nryn]

Originally Posted by AirMiles

Nyrn, sounds like my refrigerator is working about the same as yours. On its highest setting it will get 33 degrees in fridge and teens in freezer. I’m ok with this too. But mine needs to be perfectly level for this performance. Otherwise, the fridge can climb to the mid- 50s pretty quickly.

Could be. Mine has never been in the 50s once cold, though, at least as far as I know. And I don’t think I’ve camped more than .5” out of level, so maybe that’s it.

[TouringDan]

I camped in downtown Raleigh for 5 days from 9/24 to 9/29. I have 200 Ah of lithium in my Airstream and started at 100 % SOC. After 5 days of camping, I was down to 77% SOC. The Airstream wasn’t connected to any solar during this period.

Now I have 400 watts of solar on my truck bed cap and this was keeping my 100 Ah lithium battery in my truck bed charged. This powers my 66 qt compressor fridge that I carry in the bed of my truck. Here are the specs for the fridge.
I left the house about 1:00 pm on September 24 and got to Raleigh about 5:00 pm. During this time I had the fridge running off the truck 12v power. The solar panels were charging the lithium battery. Here is a photo of the solar charging taken about 6:00 pm. The battery was fully charged having gone through absorption and float modes.

At this time I switched powering the fridge from the truck battery to the lithium battery in the truck bed. The charging profile for 9/24 and the next 3 days is shown in the next photo. The lithium battery with 400 watts of solar provided adequate power to operate the fridge although the battery never went into the absorption or float modes during this period.
The fridge performed very well considering it was quite warm. The freezer temperature was maintained at zero and the fridge was maintained at 35 degrees. No complaints.
Any comments on the fridge or solar performance welcomed.

Dan

[uncle_bob]

Hi

The only way to get a reasonably efficient "DC" fridge is to do a compressor based unit. That completely eliminates the ability to run on propane. Since a propane tank will keep my fridge going for a *long* time, that's certainly not a tradeoff I'd want to make. I have many other ways to load down my solar / lithium setup

Bob

[Rocinante]

When our Demonic ammonia-based fridge eventually dies, we'll replace it with Danfoss-based fridge without even blinking. We've already had the wiring put in for it.

[AirMiles]

Originally Posted by TouringDan

I camped in downtown Raleigh for 5 days from 9/24 to 9/29. I have 200 Ah of lithium in my Airstream and started at 100 % SOC. After 5 days of camping, I was down to 77% SOC. The Airstream wasn’t connected to any solar during this period.
Attachment 353702
Now I have 400 watts of solar on my truck bed cap and this was keeping my 100 Ah lithium battery in my truck bed charged. This powers my 66 qt compressor fridge that I carry in the bed of my truck. Here are the specs for the fridge.Attachment 353703
I left the house about 1:00 pm on September 24 and got to Raleigh about 5:00 pm. During this time I had the fridge running off the truck 12v power. The solar panels were charging the lithium battery. Here is a photo of the solar charging taken about 6:00 pm. The battery was fully charged having gone through absorption and float modes. Attachment 353704

At this time I switched powering the fridge from the truck battery to the lithium battery in the truck bed. The charging profile for 9/24 and the next 3 days is shown in the next photo. The lithium battery with 400 watts of solar provided adequate power to operate the fridge although the battery never went into the absorption or float modes during this period. Attachment 353705
The fridge performed very well considering it was quite warm. The freezer temperature was maintained at zero and the fridge was maintained at 35 degrees. No complaints.
Any comments on the fridge or solar performance welcomed.

Dan

Excellent report Dan! There is a solution for a solar powered refrigerator. I don’t believe it’s possible to power an Airstream DC refrigerator with solar continuously. There’s just not enough roof space to replace the daily power draw. Your refrigerator takes half or less power to operate. A 5.5A draw is sustainable with a 400W or larger solar array. I believe I could power your refrigerator and my other power needs with the 600W of solar that fits on my Airstream roof.

I’ve been successfully running my three-way refrigerator on propane and keeping the temperatures at about 10 in the freezer and 34 in the fridge. We’ve been able to replenish our ice cube stash and all is well with the refrigerator as long as we keep the refrigerator level when parked. It also works well when traveling down the road and DC can be used while traveling when it’s sunny.

I’m with Uncle Bob on this one. I’ll just keep running my refrigerator on propane at a draw of about one pound per day. When traveling on sunny days, I will use the DC option.

[Rocinante]

For what it's worth, while traveling down the road we mostly run our two-way Dometic on AC power (via our Victron hybrid inverter/charger) and leave the propane turned off. Most days we arrive at our destination with a full or nearly full battery. If it's cloudy or especially warm, we might be at 80-90% because it's harder to keep up on cloudy days and on days where fridge duty cycles are longer due to the heat. If one of the latter applies and we know we'll be dry camping at our destination, we'll run the fridge on propane because that way we know for sure we'll arrive with the batteries at 100%. (We're pragmatic, not proud, haha.)

[Bigventure]

I thought I would add some to the tread. I installed 4 100 Renolgy panels to my factory 10 gauge wiring. They are all in parallel. I upgraded the wire from the controller to the batteries and the grounds to the buss bars. I also sold my 2- 6 volt Interstates and replaced them with 2-170 AH Renolgy cells. In addition I replaced the cross connections between the batteries.

It’s seems to be work very well. We camped for a month going 2-3 days without hook ups. We ran the furnace most nights. The set up made more than enough power for our needs.

[AirMiles]

Thanks Rocinante for your refrigerator input. I will also try to run DC when traveling. I traveled today on propane because of overcast conditions and a dry camping destination. DC use will definitely be situational since it’s not sustainable on solar.

Thanks Bigventure for sharing pictures and performance information from your 400W parallel configuration on the factory prewire. Looks like it’s working perfectly. About three times solar panel Wattage in Watt hours each day. Nice installation. Looks like with Lithium batteries, you get more battery charging because they stay in bulk until nearly fully charged. My wet-cells spend two to four hours per day in the less efficient absorption mode.

[GMFL]

Well I’m in the process of gathering my supplies for a large modification to my current solar set up. Going to upgrade for 200 watts to 400 watts and ditch the factory 10AWG prewire I’m currently using and shift over to a homemade combiner box and 4AWG wire feeding my Victron 100/30 change controller.

I’m in the electrical business and in Pricing 4AWG wire through my supplier it’s was running $1.99/ft for single conductor fine strand wire. My project is going to require 20’ run x 2 leads. So a total of 40’ of wire =$80.00

Well here’s the part y’all can beat me up on.........

I was at my local auto parts house today and ran across a nice 20’ set of jumper cables using 4AWG wire with a nice PVC jacket for......... $29.99! The clamp ends are decent, but I do not need them just the wire.

So what do you think?

[AirMiles]

4AWG is 4AWG to me. Nice find to save $50. I think 400W of solar is the sweet spot for the power needs of an Airstream. You are going to like your upgrade!

[GMFL]

Originally Posted by AirMiles

4AWG is 4AWG to me. Nice find to save $50. I think 400W of solar is the sweet spot for the power needs of an Airstream. You are going to like your upgrade!

That’s my thought also.

[CarterKraft]

I imagine the difference is in the temp rating of the jacket.

That's assuming the conductor is the correct size per AWG. I would check that part of the equation though to verify it is the correct size because as a jumper cable I would think there would be close to zero standards about sizing, UL rating etc. where as a wire would be rated for a certain use.

And on EDIT: After looking at the picture closely it states its not Copper wire but Copper Clad Aluminum, known to the automotive wiring world as CCA. Results vary but just not it's not Copper wire and is priced accordingly. I think it has it's place as weight saving on certain applications but in situations where voltage drop is very important I would skip it.

[rowiebowie]

Originally Posted by CarterKraft

I imagine the difference is in the temp rating of the jacket.

That's assuming the conductor is the correct size per AWG. I would check that part of the equation though to verify it is the correct size because as a jumper cable I would think there would be close to zero standards about sizing, UL rating etc. where as a wire would be rated for a certain use.

And on EDIT: After looking at the picture closely it states its not Copper wire but Copper Clad Aluminum, known to the automotive wiring world as CCA. Results vary but just not it's not Copper wire and is priced accordingly. I think it has it's place as weight saving on certain applications but in situations where voltage drop is very important I would skip it.

Good catch. Explains the price.

For his solar application, 4Ga copper is overkill, so even copper clad aluminum may be semi-over-kill. Needs to check resistance charts to know for sure.

[CarterKraft]

Per this voltage drop calculator I got 1% increase in drop from copper to aluminum with a 15' cable at 14v and 30 amps.

https://www.rapidtables.com/calc/wir...alculator.html

[GMFL]

Originally Posted by CarterKraft

I imagine the difference is in the temp rating of the jacket.

That's assuming the conductor is the correct size per AWG. I would check that part of the equation though to verify it is the correct size because as a jumper cable I would think there would be close to zero standards about sizing, UL rating etc. where as a wire would be rated for a certain use.

And on EDIT: After looking at the picture closely it states its not Copper wire but Copper Clad Aluminum, known to the automotive wiring world as CCA. Results vary but just not it's not Copper wire and is priced accordingly. I think it has it's place as weight saving on certain applications but in situations where voltage drop is very important I would skip it.

I noted same thing after a closer look. Taking it back tomorrow.