12v fridge woes, battery bank and solar array questions

[distracto]

Hello everyone, relatively educated user here with some boondocking issues related to the Everchill 12v fridge the DW pushed for....

So a brief backstory... We recently sold our 2015 Jayco White Hawk 23MBH and purchased from a dealer (first ever brand new trailer) a Freedom Express 257BHS. We thought the Jayco had a 10cu ft fridge, so ordered the new trailer with a 10.7 cu ft DC fridge as the wife didn't want to downsize. Turns out the Jayco was an 8 cu ft fridge and a two way would have been just fine. But noooo we had the DC on order with one 175w panel and 30a controller so figured we'd be fine. I had a 200w panel of my own on hand and two Renogy 170ah LiFePO4 batteries ready to go, so we should be laughing, right? Haha nope! We are drained by day 4 with no hookups.

Sooooo.... I'm trying to find ways to let us boondock indefinitely through solar and an appropriately sized battery bank. As I'm realizing, this won't be possible with what I have on hand, and with what was supplied by the manufacturer. Between claims by the dealer, the manufacturer's marketing (I know, I know), and some internet research (thanks for nothing, Josh the RV Nerd), we thought we'd be golden.

We are misers with energy, lights off and fans on low, so all we run is the fridge, two maxxair fans, and some lights, charge USB devices... No cpap machines or anything like that, and we don't care about ac appliances (yet)

I have two 195w eco worthy panels on the way to increase my solar array, and just picked up a Victron Smart Shunt to help figure out what the coach is actually drawing. This has become extremely frustrating!!

So I guess I'd like to confirm a few things :

Who else has a 12v Everchill fridge and exclusively boondocks?

How many watts /volts /amps can I run safely through 10AWG and an OEM Jaboni 30a controller?

How bad is it to mix and match solar panels? I understand I'll be gathering energy at the lowest common denominator.

Here are the specs for what I have at the moment :

I am sure this is the rebranded oem controller I have: https://zhcsolar.com/product/mppt-solar-charge-controller-30a/
A supposedly 175w panel from Jaboni (I see no branding or info on it, so can't verify)
1x 200w panel from Renogy https://www.amazon.ca/dp/B08MZJPRX7/ref=cm_sw_r_cp_apa_glt_i_PNHYT1JDSCK8QJN6N257?_enc oding=UTF8&psc=1
2x 170ah Renogy LiFePO4 https://www.renogy.com/lithium-iron-phosphate-battery-12-volt-170ah/
Adding soon two (or as many as I can) eco worthy 200w panels https://www.amazon.ca/dp/B00ZOOGVOQ/ref=cm_sw_r_cp_apa_glt_i_KZF4Z6CNB0AN0W16FK8R
And the evil everchill fridge plus two Maxxair fans...

Any advice on how to keep ourselves going indefinitely via solar and batteries without using a generator would be awesome. Thanks everyone!

[Chris61]

Get a Victron 30a dc-dc charger with bluetooth, you like Victron it seems and as much solar as you can fit on your roof.

I have ordered a new 5th wheeler with this fridge, also called Magic Chef, but has same model number.

It will be interesting to see what others say

[jbflag21ds]

Does that fridge have an switch to reduce power use when boondocking? I've heard some do.

A small generator would be cheapest solution, allowing you to charge batteries when needed. One that can run on propane means no extra gas to carry but there are drawbacks too

You can run 30A through good 10AWG wire.

[distracto]

Originally Posted by jbflag21ds

Does that fridge have an switch to reduce power use when boondocking? I've heard some do.

A small generator would be cheapest solution, allowing you to charge batteries when needed. One that can run on propane means no extra gas to carry but there are drawbacks too

You can run 30A through good 10AWG wire.

It has a standby mode, I should look into that, could use that over night when it's cooler. I think there's also a DC heating element for the auto defrost which I'm sure is a pig on the batteries.

Prefer not to use a generator, but perhaps wise to bring one for the first long trip... Next week we leave for the Okanagan for 17 days off grid.

To bypass the existing 10GA wiring, maybe I run a new line down and have a second controller. Is that a popular thing? Two charge controllers in parallel to the battery bank? Might be more cost effective than upgrading what already came with the trailer.

Thanks for the replies, I'm hoping this thread helps others as well who boondock with these DC fridges.

[Old Coyote]

See my signature for the equipment my TT has. I recently did a test run at 8,000 ft in the CO Rockies, with the TT parked under trees that only allowed a max of 2 hrs a day of direct overhead sun. I was on Battery & Solar power only, with these Loads: 12V fringe running normally 24/7, lighting, water pump, furnace at night, maxxair fan at day, & USB charging various devices.

My 250AH battery dropped ±20% (50AH) per day with only the 190w partial solar input, I ran in this condition for 4 days before recharging via shore power.
I have since added a 200w portable solar suitcase to place in the sun when camping in the shade of trees. On a trial run it produced 75AH in ±8 hrs. I expect it to cover all my boondocking power needs. I built a 10AWG SJOOW x 20 ft cord between the Portable Solar and the TT (Solar on the Side) SAE port.

On 10AWG wire useage, distance (ft) & Load (Amps) are VERY important. There is a very good calculator that allows for various Solar DC Voltages at http://www.rv-project.com/tips/wirecalc.php
Be sure to use the calculator input for "Ground Wire" and a 3% Voltage Drop, this will calculate using the round trip distance between panels/controller and TT battery, or Panels and Controller.

[tomkatb]

You need about 800 watts of panels if the roof is big enough. That would create up to 200 AH on your best day. A new higher capacity controller for the panels and new wires as all of yours are too small.

Also a generator to recharge today on a every other day cycle.

The battery monitor goes without saying.

The generator is still a good idea.

All of this depends on where you live and play.

[Chris61]

I just read that Rockwood is considering making this fridge standard and the 2 way as an option. 1 solar panel is standard and a 2nd one is optional. 2 190w solar panels should be standard as a minimum.
Choosing a camping spot with full sun is another way to maximise good solar charging. I do carry a generator, only use it 2 or 3 times a year. Charging with a generator and lead acid batteries should be done early in the day when batteries are at their lowest, not trying to top them up later in the day. Lithium charging doesn't really matter. A dc-dc charger works well while you are driving, using the alternator to supplement the solar. Correct wire sizing is very important as well.

[Hclarkx]

I don't have the EverChill. I have a Nova Kool. Most of the typical 8-10 cu ft two-door (fridge and freezer) units are pretty similar and use one Danfoss/Secor 12V compressor. If the fridge is a readily available model, you should be able to get some specs on it such as it having one or two Danfoss/Secor compressors, the typical current draw (5.2 amps per compressor with Danfoss/Secor) etc. You might also be get the expected duty cycle in a given ambient (I got "50% in 70F ambient) from Nova Kool.

You already have the fridge, so you can do some measurements to confirm data or supply missing data.

From my research, it seems most of the 12V fridges are designed for 50% duty cycle around 70F and 100% duty cycle at 100F. Indeed, if you calculate the thermal energy transfer though the fridge and freezer walls, it indeed would take twice the energy at 100F compared to 70F. My Nova Kool has one BD-35 Secor (Danfoss) compressor and is 9.1 cu ft two-door, freezer below. It runs 50% in 70F and 100% at 100F (I've since added insulation to reduce these numbers but that's a whole other story and not a good one).

So, if you have a single BD-35 compressor set to run at 3500 RPM, you can estimate the energy use for day and night times and temperatures. Or measure it since you have the fridge and know your ambient.

Assuming worst case, maybe 100% duty cycle around the clock, you will need 5.2 times 24 or about 121 Ah. About 2/3 of this will be at night from the battery. About 1/3 will be day time from solar (with the solar also re-charging the battery). If you have LiFePO4 batteries, this means about 121 Ah from solar and a battery that can supply 80 Ah overnight. Again, this is in 24/7 100F ambient. Personally, I don't go to such places!!! But, it's a place to start the calculation and maybe a credible worst-case to plan for.

With AGM batteries, much more total capacity is required and about 35% more solar to cover battery losses.

Now, you need to estimate the solar you will get. Go to PVWatts on the NREL (National Renewable Energy Lab) website. It's a 25 year old well developed solar predictor. It provides hour by hour for statistically representative weather anywhere in the US. Look at places you camp and your panel orientation and such. I camp only in the West where there's a lot of sun (though not in the Northwest) even in winter. My worst case is the California coast in late fall or early spring so I use data from there to design my system. There are large areas of the eastern US where you get far less solar and can have days on end of clouds.

For my system, 100 Ah of LiFePO4 capacity and 300W of solar was about right to cover the 12V fridge addition. Since adding extra insulation around the fridge, I've never needed all of this. Again, this is based on where and when I camp.

[MrPalazzo]

I think you're finding that the 'allure' of solar being the end-all to camping off grid is not really always the 'answer', at least not ALL the time and EVERY DAY - it's just not reasonable to assume that the sun will ALWAYS be out, directly over your solar panels, and for HOURS on end. After all, it will also NEVER be out during the overnight hours!

Having said that, solar is o.k. for a backup source of power, when those things do 'align', but a secondary, or maybe more appropriately, a PRIMARY power source will probably still always need to be at hand.

Why can't your amount of solar take care of YOUR needs? Well, we all 'camp' differently, we are all in different temperature and weather environments, and many times the 'max' output of a solar panel/system is just that, the MAXIMUM you will EVER see on the BEST of situations, and probably for only a MOMENT in time.

Your BATTERY bank is also in question. They are also expensive, whether you have a single 'high end' battery type, or you have 4,6, or 8 'low end' type batteries. You can have all the solar you can afford, but if you don't have anywhere to 'store' that power, you are simply paying for expensive 'during the day only' power.

Solar is expensive, as you are probably already finding out. You 'want' quiet power, but at this point it's just not in the cards for every day camping. It's understandable you don't want to 'ruin' your environment by running a generator, but if you take that stance, you are ultimately going to have issues, unless you spend a LOT of money. If that's the case, your wife might as well get a 20qft fridge, instead!

[boondocking]

I boondocking for a month at a time and longer and never run the genny to charge my 8 year old battery bank.
Solar is an excellent main charging system and is not expensive being around .50 to.75 cents a watt now.

[Hclarkx]

Originally Posted by boondocking

I boondocking for a month at a time and longer and never run the genny to charge my 8 year old battery bank.
Solar is an excellent main charging system and is not expensive being around .50 to.75 cents a watt now.

X2!!

About four years ago I upgraded my solar to 600W and before that a 300 Ah LiFePO4 battery. I have not run the generator since upgrading to 600W. A couple of years ago I removed my 30 amp umbilical and the converter. And my unused A/C unit. I boondock and dry camp exclusively. Five months each year, fall and spring. In the 11 Western States.

I haven't hauled the generator along in over a year ... though there are circumstances where I would (predicted inclement weather, a trip to the Northwest, etc.). If I do, it will be the backup.

A year ago I installed a 12V 9.1 cu ft fridge and added some solar panels to cover it (the 300 Ah battery was sufficient). Still no generator use.

So, under the right circumstances, solar can be the primary and only power source.

Yes batteries can be expensive. But, I just built three 280 Ah LiFePO4 12V batteries for my son. Total cost about $1900. So, expensive but maybe not prohibitively so.

[Hclarkx]

Originally Posted by distracto

How many watts /volts /amps can I run safely through 10AWG and an OEM Jaboni 30a controller?

How bad is it to mix and match solar panels? I understand I'll be gathering energy at the lowest common denominator.

I thought you'd get a lot of response to these two questions but I don't see much so I'll go for it.

Safety wise you can put 30 amps on #10. Voltage rating is well above what you might need. However, if the #10 run is long, say over 50 feet round trip, a voltage drop calculation would be a good idea.

Be sure the Jaboni MPPT controller you have is the one you linked to. The one you linked to is substantial. Jaboni sells a 30A one under their own name that is far far less capable (good for only 45 volts open circuit).

Most solar controllers can have panels totaling up around twice the rated output connected to them. They will self-protect, allowing input voltage to rise to limit input power to the max output power plus losses. This is called "overpanelling" and since a 200W panel will rarely produce over 160W, not much is lost by throwing away excess over the controller rating. With panels 30 or 40% over the controller rating you may waste energy only a dozen days per year and only for a couple of hours around noon in June. A 30A controller can produce around 400W output. Input from the panels thus could be up around 500 to 600W. However, I don't see a max input rating on the controller you referenced or the Jaboni 30A on. That worries me a bit. I think I would not be comfortable going forward with 600W without seeing something from Jaboni saying it's okay.

Maybe this is academic since you have a 200 and a 170W panel so you are under 400W and likely to rarely see 300W so your Jaboni can handle the two panels you have ... if they can be combined in series or parallel.

So, for dissimilar panels on one solar controller ........ ideally you will series panels only if they have the same maximum rated current. And you will parallel panels only if they have the same rated maximum power voltage. These are ratings under industry standard conditions (temperature, sun radiation, etc.).

I say ideally because you will get the full power from all panels only when the panels are matched as noted.

So, what you need is data on the 170 and 200W panels. Their cell arrangement may make them compatible for series OR parallel operation (likely not both). Series if they have the same current rating, parallel if they have the same voltage rating.

If the voltage (parallel) or current (series) are close, say not off by more than 10 or 15%, you will lose some panel capacity but they will function. The MPPT function will help by finding an operating voltage that minimizes power loss due to unbalanced panels.

[distracto]

Thank you everyone for your responses and a great discussion.

I wanted to post a quick update before I head out to the interior of BC for 17 days of boondocking.

I ended up adding to my solar array to get just under 800 watts of solar fed through two 30A charge controllers, this through a Victron Smart Shunt to monitor usage. I finished it last night after about a week and a half of late nights and lunch breaks. It was a lot of fun and I'll post a build thread when I get back. There are still a few things to clean up and sort out, but I'm happy.

Here is a pic of the board I made to handle the devices and wiring and the panels on the roof.

Thanks again everyone!

[boondocking]

Very nice! Thank you for the update.

[distracto]

Here is a detailed thread about the installation https://www.forestriverforums.com/fo...o4-238536.html

So far so good and after a 17 day trip with no hookups, we had no problems and never dipped below 75% battery capacity!

[SK ON THE ROAD]

Originally Posted by distracto

Here is a detailed thread about the installation https://www.forestriverforums.com/fo...o4-238536.html

So far so good and after a 17 day trip with no hookups, we had no problems and never dipped below 75% battery capacity!

Great! I see now why the two charge controllers work well.