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Discussion Starter · #1 ·
Goal: Solar panel on roof of 7x14 box trailer that keeps a battery continually charged for the sole purpose of keeping our on-board mini-fridge running when we don't want to run the generator and don't have the option of shore power from house.

Steps for the goal:

1) Buy and mount solar panel, yeah? Will the cheap-azz one from Harbor Freight do the job?

2) I have no idea what to do from there. This is outside my area of expertise (no s&!t, right?), and I'm trying to learn here. Just wire the panel directly to the battery? Or do I need some sort of inverter/converter in the middle? Is it possible to overcharge the battery?

3) Will a standard car battery do the job of keeping a small fridge running and my drinks cold, assuming we get enough sun to keep it charged? I suppose some wise old haggard sparky is going to ask for the amp draw on this fridge about now, right?


Any experience you guys have had with this type of setup that you can toss my way is very much appreciated. After a couple months of having the mini-fridge on board, I'm realizing how useless it is unless we can count on it running all day.

You could make the argument that you don't "need" a mini fridge in your work trailer, and you'd be right, but I've got it anyway and now I wanna make this happen if possible.
 

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First. You need to buy enough watt to run the fridge.
Secondly. A car battery should do the work
But.
You might need to add something to protect the panel when you are on the road.
Then your fridge will probably not work during the night. The battery might lack energies before sunset.

You should try to search for dIY tutorial on how to see up the panel. You need the inverter. And a few other thing to make it work properly. And if you don't have anything to prevent your battery to ran out or juice like an automatic shut off switch it might get uses prematurely and fail.
I'm sorry for my English it's late I'm on my phone and it is not my native language: p
Hope I helped
 

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I have seen some good youtube vids on the harbor freight panels. To charge a battery you will also need a charge controller. Try out a deep cycle. You may need two.

You could also buy a wind turbine. Driving around with that you would never have to wait for wind. :whistling
 

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Why not super insulate the "ice box" cooler inside of 4-5" of tuff R foil faced foam box?
plan b get an LP fuel run camper fridge with back up 120 Volt compressor
550.00$ for 5.5 cubic ft. norcold. Or hit the camper trailer bone yard.

A semi tractor APU could Air condition the trailer and refrigerate yourfood at less cost than a solar installation of adequate Wattage and battery storage capacity.

In spite what Eco-nutters say solar power is silly, banker hours, 9 to4pm on cloudless days, less if you don't buy a powered mount to follow the sun around $$$. 220 watt(remember only ~less than 40% out of 24hrs) with inverter and transfer switch only 2800.00$ that is a lot of ice... Ooh and NO BATTERIES, ooops. Don't forget inverter losses charging and discharging the batteries---220 Watts(minus the Reefer draw during the heat of the day) in for 7-8 hrs than 16 + hours of NOTHING, average output ~70 Watts a hour for a years light bill.......if there isn't any clouds or bird caca on the panels...

Only the massive theft by Taxes then transferring through direct and indirect tax loopholes for installing them, has allowed the GDP shrinking solar cell industry to keep growing in the USA.

The LP tanks for the frig will allow you to start to grill the cold meat for lunch at the job site, and fuel the in wall heater for the winter break room...See snowmobile/ atv/dirt bike enclosed trailers converted into weekend campers, It would need about 15,000.00$ worth of solar cells and equipment to run a 1800 Watt electric hamburger grill.....
 
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90%-er
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Discussion Starter · #6 ·
Ah man...don't burst my bubble on this one. There must be a way to do this in a sustainable way. And by that, I don't mean some hippy-dippy tree-hugging "solar is the future" crap. I simply mean not having to refill a propane tank for the rest of the life of the trailer.

I guess I'll hit Youtube for the videos on the panels. But maybe I was vastly mistaken about how much power we can get out a couple panels versus how much draw a 'lil baby fridge takes?

I wouldn't even care if the fridge is cold at night, per se. I would just need the thing to kick on at about 6am to get cold for an hour, then kick off towards the late afternoon, after we're pretty much done with it anyway...maybe around 3-4pm. I know this can easily be accomplished with a timer. Still too much demand for a couple panels and a good battery?
 

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have you tried 12v cooler
it might be the easiest way around, no need for inverter, and you should even be able to run it from a booster pack
or adding it to a solar system(with charge regulator and the booster pack), . and you could even add some wire that recharge it with your truck when you are driving or plug it during the night or else.
that will probably be what I would do in your situations. a booster pack recharge by few solar panel and the truck itself when you are on the road. and I probably would plug it during the week end to have a full charge for monday.
I dont have the same problem you have,I use ice pack and a well insulate cooler,
and solar pannel would not be very cost effective for me.
I have a 150 feet extension cord on on my trailer, all my battery charger are already plugged in and fixed on a trailer shelf/or wall and can add a microwave and a heater if I need. but I dont need/use a fridge
 

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You're looking for a thermocouple based solid state heat pump that will run off of either 2 Amperes 12 Volt DC or 120 acVolt--all over the market place....4 large truck batteries would run it 2-3 days between charges or leave in your truck after adding a battery, always plug it in at home to pre cool it.
FYI, unless $ is no object(isn't wasting $$ anti-green?) Solar is almost always Silly.:jester:

Buy and install an ice-maker at home, bring a bucket to work at a fraction of what a working solar powered ice box would cost. Use the savings to retire a year earlier.... sell cooler space to coworkers/employees.

Or deep freeze two gallon jugs of water ice in your -40 sub zero deep freeze every work night.... Throw in cooler with lunch.... and you have cool drinking water...

Don't forget to charge for working off the grid.....
Proper planning has the Electric roughed in to the temp panel a week(s) before the other subs need it....

Study the science and math of solar vs the stuff that works cheaply, safely and cleanly. Learn enough accounting principles to see for yourself how financially silly spending your equity for so little gain is. America and Canada needs more informed voters that don't get sucked into supporting Scams like tax write offs for solar panels that will be junk that is creating roof leaks long before returning even a tiny fraction of the money spent to buy and install it, let alone maintaining it during its all to short life-cycle. P.S. Solar is Double silly in Northern latitudes... like Canada.

What are U remodeling that doesn't have power? Is the trailer bear proof?
 

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For a fridge you will need a lot more than one panel and 1 battery. Golf cart batteries work better than car batteries and you will need at least 2. There are many articles about the calculations.
You will also need a controller, its really not as simple as you think. I was looking into it for my camping trailer
 

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Don't waste your time here for this info.

This is an everyday type question on many RV sites. Try an RV site. They do this all the time and know how to do it for less.

Also, use an RV battery. Car battery can't handle the constant deep charging and discharging. Try Camping World or other RV supplier.
 

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Discussion Starter · #11 ·
Does anybody else get the idea that my man fourthgeneration spends most of the evening on the boards, just waiting for a post loosely related to renewable energy, just to squeeze in a few shots at it? Lol.

Just messing with you bud. I'm totally hearing your points, but this isn't really about economic feasibility on a macro scale. For me, it's about convenience (once installed), less to think about in the morning, and just plain cool factor man.

Think of it as any other hobby that you can't really justify from a money making standpoint.

It'd be neat if it would work, and while I'm not going to spend ridiculous money on it, I don't mind a certain cost to make it work. Guess I'll hit the TV boards since it seems like those guys have a good conversation going about this between people who assume it can be done.

Beaten paths are for beaten men
 

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Oh it will work and can be done. But you need to gather the information before starting to really see the cost. I was very surprised at the expense, but I still my do it.
 

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There is nothing wrong with blowing a little cash on your own boondoggle, but the current mental mush offered as facts by the "renewables" Con-men and women revolts me. The waste of hundreds of Billions of dollars yearly to appease the Angry Gods of various branches of this weeks Eco-Nutter Manias violates our Nation's Constitutional requirement of separation of Church(Faith Based Belief system like CO2 forced AGW) and State.

Please reject any ideas that blowing your $ on this is improving the environment in any way. The volcano will erupt or not no matter how many virgins or dollars are sacrificed into its crater by the Eco-priesthood or EPA.

Spending several thousand dollars to keep your lunch and beverages cold for few hours at work wouldn't reduce your impact on the Earth. If any thing the reduction in your net worth will require the further consumption of far more energy, material and labor then added value of the solar powered refrigerator, inverter and battery pack bring to your life.

Freedom requires the availability of poor choices. Enjoy.
 

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Good suggestion above to go to a RV supply site and Forum to check out systems. If you use a DC reefer then there's no need for an inverter; also consider another battery with a charging system that can be utilized when driving and that the PV panel(s) could charge when sitting.

We had big battery banks that were separated but both would charge when the generator was going (this was on a boat but it's the same concept).

PV systems are getting more affordable all the time and while 4G has some good points there's also some good arguments for the other side, some of which have nothing to do with how 'green' they are.

Here's a link to a guy I know who specializes in RV and boat solar; he told me he got into it after draining his battery in an Oregon state park that didn't allow generators to run after dark.http://zampsolar.com/
 

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Head Light Bulb Changer
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I second the RV sites for info. Are you near a large RV center? They can point you in a better direction. I hate to say it (and bust your bubble), but trying to run a standard mini-fridge like you propose, is a huge waste of money. I figure at least $2000 in parts. I think ice and a cooler will be more cost effective in the long run. Or get a RV fridge that is a 2-way (propane and 120v). It will switch automatically between the 2 and they're pretty efficient running on gas. I have a 6 cf fridge/freezer that will run almost 3 weeks on a 20lb tank. And it makes ice! But you need 12vdc (battery) to run it also. You can get a nice one for $500 used, or about $1500 new.
 

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The Dude
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Don't hook a panel right up to the battery, you need at least a charge controller. You can get inverters that have charge controllers built in if you want. You'll need more batteries for longer autonomy (no sun), and more panels to charge more batteries in a reasonable time. There is maths to size the system.

It gets very expensive very fast.
 
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