Electric Fridge/freezer set up on 2018 Airstream Grand Tour EXT

[pas96]

We have a 2018 Air Stream. Grand Tour EXT, and have stayed overnight with our 300 watt solar panels (stock, as purchased from Airstream), along with our electric fridge and freezer. With the freezer temp set low, and fridge on #4, we seem to totally stress our stock AGM batteries each night. Is this a poor design on Airstreams part, or can we upgrade to make boondocking a true option?

[Pahaska]

The solar panels are of no help past late afternoon. A stock GT will not last the night with both refrigerator and freezer running.

Turning off the freezer overnight will help a lot. We plan to not use the freezer at all during our 4-night no-hookup stay at the balloon rally.

I have a Yeti Goal Zero 1000 to help cover the night hours. Solar, and, if necessary, the generator to recharge the GZ each day. I have both the fast AC charger and the DC MPPT charger for the GZ to optimize fully charging it each day..

I'll be turning off the main disconnect switch and patching 12v from the GZ into the 12v system. Our overnight loads will be some lights, refrigerator, and occasional water pump.

[pas96]

Thanks so much for y0ur advise. I figured it was impossible to use the freezer overnight....(wonder why airstream would offer the set up and know it can't be done. Do you think two more AGM batteries installed would help? Sounds like it would be expensive.

[Boxster1971]

Originally Posted by pas96

We have a 2018 Air Stream. Grand Tour EXT, and have stayed overnight with our 300 watt solar panels (stock, as purchased from Airstream), along with our electric fridge and freezer. With the freezer temp set low, and fridge on #4, we seem to totally stress our stock AGM batteries each night. Is this a poor design on Airstreams part, or can we upgrade to make boondocking a true option?

WELCOME to AirForums! It is a bit shocking to learn that an Interstate at nearly $200,000 can't even do one night off-grid without stressing the batteries. That's why I've often mentioned that Airstream is behind most other B-vans on the market. The current Interstate design is only good to go from one full hookup campground to another. Pretty pathetic.

The simplest upgrade that would help some is replacing that trash Atkinson solar controller still being used by Airstream.

[Boxster1971]

Originally Posted by pas96

Thanks so much for y0ur advise. I figured it was impossible to use the freezer overnight....(wonder why airstream would offer the set up and know it can't be done. Do you think two more AGM batteries installed would help? Sounds like it would be expensive.

Airstream is stuck in the past! As I recall your 2018 only has two 12V batteries. Adding two more will definitely help. The new Interstates have four batteries.

[swilly43]

Echo what Boxster says. Spend some time perusing the forums. I suggest a multiprong approach.
1. Eliminate all parasitic loads, gas valve, inverter if not using it
2. Upgrade for efficiency, replace Atkinson solar controller and get a true battery monitor and learn what uses energy the most, battery combiner perhaps
3. Increase capacity by adding batteries, swapping to lithium or patch in power like the Yeti
4. Use a portable cooler inside your freezer to help keep frozen items cold. You can use the freezer when you have excess power and turn it off when outside temps are cooler.

I have used this methodology and it works. We can go several days without plugging in or using the genny. Search the forums for each of these topics and pay attention to those who post their results. Ask for help if you need it. This forum rocks wrt helping you get the most out of your AI

[Ryoungca]

I also echo Boxster's advice. We went from 2 stock batteries to 4 golf cart batteries. That change increased our off grid time from less than one day to about 3 days. Just moving from 2 stock batteries to 4 stock batteries might get you through at least one night.

[pas96]

when you say golf cat batteries...are you talking lead acid? If so did you have to remount inside? Just curious...thanks so much for your time.

[nvestysly]

Originally Posted by swilly43

...
1. Eliminate all parasitic loads, gas valve, inverter if not using it
...

+1 on hidden loads

We found the gas valve, a.k.a. the solenoid for the propane line, is a huge load on the electrical system. Search this forum for a thread regarding how to install an interior switch to operate the solenoid. Adding an interior switch is probably the best upgrade we made to allow us to go more than one night without hookups.

We have very little need for the inverter for several reasons. When we use the inverter we use it sparingly and turn it off when we're finished watching television or charging a laptop or similar. The inverter is a silent killer - it will draw your batteries down even if you're not using the inverter outlet. The inverter itself uses power even if nothing else is using power, and the inverter is probably running the refrigerator too so you're taking DC, making AC then converting to DC again. Not efficient.

We have a 2010 Interstate, no solar and we can certainly go one night without hookups. Of course we don't have the large freezer/refrigerator.

Adding a true battery monitor system was also a very useful upgrade for us. Now we can determine, with reasonable accuracy, how much power we use from the batteries.

Don't hesitate to use the generator. We found 30 minutes in the morning and 30 minutes in the evening goes a long way to keeping us powered up even when boondocking for days at a time. Driving the vehicle during the day will recharge the batteries too.

[AirMiles]

I don't know the amp draw of the Grand Tour's DC refrigerator, but it its anything like my 2018 Globetrotter, there's not much you can do. My Globetrotter's refrigerator use 14A while cooling. I've found it runs nearly constantly when on DC. That means I would need 14A times 24 hours, or about 366AH of usable battery for one day of refrigerator only use! I also need about 100AH of battery for my other usage such as lights, pumps, radio, fantastic fans, furnace fan, etc.

Let's do some solar math. Recharging 466AH of battery use would take 466AH times 13.5V, or about 6300Wh of solar production. On a good day of solar, I get three times solar panel wattage, so divide 6300WH by three equals 2100W. I would need 2100W of solar panels to provide the power needed to run my DC refrigerator and my other DC usage from a single good day of solar! Try putting 2100W of solar on any Airstream's roof. It's not possible. Even if I added Lithium 100A batteries, I would need six batteries to just boondock for one night and then would need to be connected to shore power to recharge because I don't have 2100W of solar.

What I've found with 600W of solar panels is that I will only operate my DC refrigerator while traveling on sunny days. Any other time when not on shore power, I just operate my refrigerator on propane.

[rowiebowie]

++++ on advice given so far to reduce unneeded parasitic draws. I spent some time (with advice on this forum) and made efforts to do just that. Even use a 12v tv (of course mine tv is small so not sure how big you have or how much drain it takes) so we actually camped our first 1-1/2 yrs. never using the inverter.


Fast forward from then to now and I did a Renogy 200Ah lithium battery swap (moved batteries inside) and have a little more than 2x useful amp hours. Also did lithium compatible upgrades to a Victron Solar Controller, Renogy 3000W inverter/charger, Renogy DC to DC alternator charger, and Renogy State of Charge Monitor (SOC).


We could easily go overnight, but not two, with original two lead-acid batteries. Now, we use the Inverter to power more thing like the microwave and really increased our power consumption because we no longer have to worry about a night or two. Could easily do three nights if we went back to our old conservation ways. Not cheap, but lithium is a nice upgrade.


However, it seems your Grand Tour model with the large refrigerator and freezer has battery capacity problems much more than Interstates or models like mine with a smaller 3.1cf Nova Cool compressor fridge.


To assist you, while my Nova Cool 3.1cf seems to run much too often (subjectively 3/4th of the time even in cool climates) the consumption observed on my SOC monitor is only 41 watts (3.154 amps) when running. I'll bet your large fridge consumes much more (hope it is not anywhere near AirMiles Globetrotter). Maybe someone will post the results of their GT fridge consumption.

[Ryoungca]

Originally Posted by pas96

when you say golf cat batteries...are you talking lead acid? If so did you have to remount inside? Just curious...thanks so much for your time.

I used Lifeline sealed lead-acid batteries (GPL-4CT 6v) and I installed them in the well behind the rear seat of my 2015 model. My original batteries were in a metal enclosure under the back seat. I can link to the post about this work if you're interested.



I think your batteries are mounted under the coach and I know others have added more and larger batteries in that area as well.