A "minimal" solar kit for a nOOb? (LONG!)

[Martinjmpr]

Thanks for the input.

You sure don't need a 40a rated charge controller for a 100w solar panel. 10a would be big enough for that.

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I can save $70 by going with a 20a MPPT controller, if that's sufficient for 2 x 100w panels then that's probably the way I'd go.
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Or, what I would do, is bring along a decent battery charger and just hook it to the truck battery when shore power is available. Then you only have to move the fridge to the trailer when boondocking.

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Actually I have an easier and cheaper solution than that: I carry a couple of long 120vAC outdoor extension cords. Since the fridge will run on 120vAC as well as 12vDC when I have shore power I disconnect the 12v connection entirely when the truck is parked and just run the extension cord to the shore power (eventually I'll run it to the trailer but right now the trailer doesn't have any external 120vAC outlets on it - another project I have to work on!)
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Sure you do, you have two ways - solar and the truck.


Again, I appreciate the advice. I think I've learned a lot in the past week or so since posting this! :ylsmoke:

 

[Martinjmpr]

Got it - but now I need connectors!

UPDATE 7/17: Ordered the Renogy 100w kit with the 20a MPPT controller. Finally had a chance to hook it up today. I hooked everything up according to the manual (pretty simple really) and hooked it up to our T@B trailer.

I believe the system worked (I only gave it a really cursory test though.) What I did was I unplugged our trailer from the house current (we keep it on house current all the time to keep the battery charged up, as it has a built in charger with a controller/inverter that keeps it from overcharging.) Let it sit disconnected from power for about a half hour while I worked on other stuff. Just before I hooked up the solar I checked the battery voltage and it read 12.66, which is what it reads when full (It's a 75ah deep cycle SLA.) As soon as I hooked up the solar panel, voltage jumped to (I think) 13.5 or 13.7. The MPPT controller has a little LED window that shows green when charging and a blinking green light when the battery is fully charged.

The system will be tested out (for real) this coming weekend on a 4 day camping trip with no power. I need to jury rig some kind of plastic box for the controller to keep it out of the weather and I just plan on propping the panel up against a tree or against my truck. We'll keep the fridge inside the trailer and hope it's not too noisy. As a backup, I got a couple of marine terminals for the truck battery so if necessary I can hook the solar panels up to the truck and see how that works (though I'm not crazy about potentially running down a 55ah non-deep-cycle starting battery.)

I had hoped I'd be able to use the SAE power connector that is built into the battery/propane tank cover on the trailer but I could see early on that wouldn't work - the wire on the SAE connector (from a battery tender) was probably 14 or even 16g. The wires that came with the Renogy kit were very stiff 8AWG. They are about as thick as a #2 pencil an just about as stiff!

The kit comes with ring terminal connectors for the battery end, and the solar panels themselves have a nice QD connector but the end where they go into the MPPT controller uses bare wires and phillips head screws:





What I'm looking to do at this point is to build some kind of wooden box for the controller and permanently mount the controller in there. But in order to do that I'll need some kind of quick-disconnect that I can put in the box so I can just plug in and unplug the wires. What are the folks out there using and more importantly, where did you get them? I couldn't find anything that would work with my heavy, stiff, 8AWG cables in any auto parts store nor in any home type store. Is there anywhere else I can find these locally? I'm looking for something local because I need to be able to try stuff out and then go back and get something different if it won't work.

One final wrinkle, I don't have any experience with soldering so I'm hoping to find something that will either clamp on with a screw or crimp on in some fashion.

Thanks in advance for any advice on connectors. Also if anyone's built a controller box, I'd like to see yours just to see how you did it.

 

[AndrewP]

Can't you just mount the controller inside the tongue box? It can stay hooked up full time to the batteries, no problem.

PV wire is usually very hard to work with. The plastic covering is very stiff, you may find it easier to use marine duplex wire, or even low voltage landscape wire.

I have a buddy with a TAG or TAB teardrop (it's the smaller of the two). The factory wiring to the built in fridge was poorly done in his and there was enough resistance in the connections to trigger the battery saver voltage limit on his fridge during motor start up, so it never worked right. And the factory installed "solar" input SAE plug was wired with reverse polarity. Really disappointing quality control. It's all fixed now.

The solution was new wiring to the fridge, and the factory single (and small, and inadequate) trailer battery was upgraded to 2 golf cart 6 volt batteries in series with 10gauge wire feeding the fridge. He runs a 100 watt Renogy folding panel to keep up with the fridge when dry camping and all is good. The upgraded batteries do fit in the tongue box, but the supports on the floor had to be redone. But he's gone from constant problems with the fridge to perfect cold beverages with wiring he never has to think about and plenty of power.

Good luck on your weekend away. I suspect you'll need to upgrade your batteries pronto on return.

Just an aside-but I thought the TAG/TAB was a really cool design, but they clearly cut costs on the electrical, to the point of negligence. You may want to go over that very carefully.

And I agree with Verkstad, that Anderson powerpoles are the way to go for making temporary connections, and if you just buy the $39 crimper up front, you will be happy forever with the Anderson system. It would be worth upgrading your skill set and learn to solder when needed. But, if you mount the controller in the Tongue box, you won't really need any power poles or solder, just decent heat shrink type terminals.

 

[jscusmcvet]

Martin - your set up should work just fine for your purposes. We run our Indel B 50 and the trailer interior lights and water pump off our trailer house battery and 45w panels. Never had an issue. There are experts with far more knowledge than mine here, but it has worked for us. We take care to keep the fridge in the shade, out of direct sunlight and that helps a lot.

 

[Martinjmpr]

Can't you just mount the controller inside the tongue box? It can stay hooked up full time to the batteries, no problem.

PV wire is usually very hard to work with. The plastic covering is very stiff, you may find it easier to use marine duplex wire, or even low voltage landscape wire.

I have a buddy with a TAG or TAB teardrop (it's the smaller of the two). The factory wiring to the built in fridge was poorly done in his and there was enough resistance in the connections to trigger the battery saver voltage limit on his fridge during motor start up, so it never worked right. And the factory installed "solar" input SAE plug was wired with reverse polarity. Really disappointing quality control. It's all fixed now.

The solution was new wiring to the fridge, and the factory single (and small, and inadequate) trailer battery was upgraded to 2 golf cart 6 volt batteries in series with 10gauge wire feeding the fridge. He runs a 100 watt Renogy folding panel to keep up with the fridge when dry camping and all is good. The upgraded batteries do fit in the tongue box, but the supports on the floor had to be redone. But he's gone from constant problems with the fridge to perfect cold beverages with wiring he never has to think about and plenty of power.

Good luck on your weekend away. I suspect you'll need to upgrade your batteries pronto on return.

Just an aside-but I thought the TAG/TAB was a really cool design, but they clearly cut costs on the electrical, to the point of negligence. You may want to go over that very carefully.

And I agree with Verkstad, that Anderson powerpoles are the way to go for making temporary connections, and if you just buy the $39 crimper up front, you will be happy forever with the Anderson system. It would be worth upgrading your skill set and learn to solder when needed. But, if you mount the controller in the Tongue box, you won't really need any power poles or solder, just decent heat shrink type terminals.

Mounting the controller in the tongue box won't work. Actually, the T@B doesn't actually have a true tongue box. What it has is a plastic "cover" for the propane tank and battery - but the cover has no back and no bottom, so it's not a "box" in any real sense. Replacing that setup is on my list of things to do before next camping season (my current thought is an expanded metal platform running the width of the trailer with a true tongue box mounted on it, and the battery and propane tank outside of the tongue box.)

Also, I want a more flexible system that can work on the truck as well as the trailer so I don't want the controller to be anchored in one place. Finally note that we are NOT using the Norcold refrigerator that is in the back of the trailer - that fridge is not really a very good refrigerator, instead my Indel-b/Truckfridge TF-41 will be sitting inside the living compartment of the trailer and plugged into the 12v outlet.

When we are camping in a site with 120vAC power, we will use the Norcold for drinks but anything that could spoil goes in the Truckfridge.

In any case, having the fridge in the trailer would be option 1, option 2 would be to leave the Truckfridge in the tow vehicle and attach the solar panels to that. I'm not keen on that option for a couple of reasons: First of all, I don't want to run the risk of my starting battery discharging past 50% (currently only one battery in the Suburban although I have started getting the parts to put a second battery in there) and second, the battery in the Suburban is only 55ah, whereas the trailer has a deep cycle 75ah battery.

 

[Martinjmpr]

Speaking of upgrading the trailer batteries, one of the people coming to the camping trip this weekend has a trailer identical to ours and he's already gone with 2 x 6v batteries which gives him an amazing 208ah! We've been corresponding and I'm definitely going to check his system out as I'd like to do something similar. With 208ah I could potentially go for 3 - 4 days without needing any auxiliary power.

 

[Martinjmpr]

I have a buddy with a TAG or TAB teardrop (it's the smaller of the two).

That would be a T@G.

The T@Bs with the inside kitchen get a very slick 3 way fridge that will run off of propane. Unfortunately they couldn't figure out how to put a 3 way in the Clamshell model (the one with the outside galley like we have) so we get an inferior 2 way fridge that is 12v/120v. On 120v it works fine (will actually freeze bottled water in a couple of hours) but on 12v it's marginal at best and quickly drains the battery (lots of complaints about that on the T@B forums.) I would guess the T@G gets the same crappy Norcold fridge since it also has a clamshell design.

If I had my way we'd just get rid of the Norcold anyway and in its place we'd have a sliding drawer for our Truck fridge. Pleasant Valley (the manufacturer) is actually pretty amenable to customizing but of course you have to order it from the factory in order to do that - we bought ours off the lot so that wasn't an option.

We looked at a lot of trailers when we were shopping for this one and despite some glitches (like the rear axle that prematurely wore out our tires last year and was replaced under warranty) the QC of these trailers is definitely above average. Other models we looked at were the Whitewater Retro and the R-Pod.

We didn't like the fit and finish of the Whitewater and the R-pod was just way too big and heavy for just two of us. If we had kids or grandkids that camped with us we might consider it though (R-pod must have hit a nerve with the RV community because there are now multiple copies of the R-pod being made by other manufacturers: Winnebago makes the Winnie Drop which is a straight copy of an R-pod and Jayco just introduced the Hummingbird which is also a near-copy of an R-pod.)

 

[Martinjmpr]

First experience with solar - mixed results...

Updating this: Got the basic Renogy kit with the MPPT 20a controller and the single 100w panel. Thought I'd share my experiences and results from the first camping trip using the solar panel.

We camped at a lake in the Colorado Mountains that has no power of any kind (Wellington Lake near Bailey for those who are familiar with the area, near Buffalo Creek.) We were on the West side of the lake, where there is a small peninsula that juts out towards the East.

I should probably preface this by saying that we camped at the same spot last year with the same trailer and the same fridge (Indel B TB-41.) The difference was that last year we kept the fridge in my 4runner running off the 4runner's battery. We would be there for 4 days/3 nights and my thought then was that I would start the 4runner and run it for about a half hour/45 minutes twice a day, basically at breakfast and dinner, in order to keep the battery charged (I did not have a volt meter with me and didn't check the battery.) On the last day, Sunday, I figured that since we would be leaving by 11:00 in the morning, there was no need to start the truck as I would be starting it when we left. This was a mistake because by 10:30 or so when we left, the battery had gotten discharged enough that it needed to be jump started. It was then that I started thinking I need to get some kind of solar setup.

This year, after doing a lot of research I realized that it didn't make sense to try and run the fridge off of my 55ah starter battery in the truck when the camper (2014 T@B Clamshell) has a bigger battery anyway (75ah SLA.) So instead of leaving the fridge in the truck we put it in the trailer and plugged it in to the 12v outlet there.

As I said in the title, the results were "mixed" but a lot of that has to be attributed to the location and the weather. Last year we camped on the same peninsula but we camped on the South side, which would have given us maximum sun exposure for the panels. This year, though, the wife wanted to camp on the shadier North side. This presented a challenge for solar use as the area is forested, and it meant that I was constantly moving the panel in order to keep it in the sun. The weather also played a factor - we had a "monsoonal flow" this past weekend that meant afternoons normally saw cloudy skies and intermittent rain, obviously diminishing the amount of power going to the panels.

However, our setup worked. The fridge stayed cold and only shut down once due to low voltage. It was pure luck that it happened just as I stepped into the trailer to check the fridge, the temperature display flipped from 32 to "E1" which is the code for a low-voltage shutdown. Immediately I checked the voltage cutoff switch (the Indel-b has a 3 position voltage cutoff switch) and set it from "medium" to "low" and the fridge came back on. Then I moved the solar panel into more direct sunlight. That was on Friday and the fridge worked fine until we left on Sunday morning.

Before I set up camp I checked the battery and it measured 12.65v, so basically a fully charged SLA. When we left on Sunday morning, it was down to about 11.79 - obviously not good. If that had been a starter battery it would definitely have needed a jump start. But since it wasn't a starter battery, no problem and I'm hoping that being a "deep cycle" Marine/RV battery it is not the kind to be damaged by discharging to that point (though I don't want to make a habit of it.) If I seem cavalier about the condition of the battery it's because I intend to replace it, most likely with a pair of 6v batteries wired in series - this should give me maximum AH (our friends who have an identical trailer have done this, in fact I got to check out their setup this weekend and it's pretty nice. They have 208ah total!)

So my lessons learned from this are: Site location is paramount if you're camping in a forested area. Moving the panel was a total PITA and I don't want to have to do that again. Fortunately our next campout without power is at Beecher Island in Eastern Colorado near the Kansas state line (if you've ever been to the Colorado/Kansas state line you'll understand that "too many trees" is not a problem they have out there. )

Second lesson: I bought the basic 100w fixed panel and I should have gotten the folding panel made for traveling. While the panel I have works, it's huge, takes up a lot of space and there's not really a good way to carry it (I just put it back into the shipping box for transportation.) When we go to Beecher Island we won't have the Kayaks so I may be able to put the panel on the roof of my Suburban but I'd still like to have a decent case to transport it in.

The stiff 8AWG wire was not fun to deal with and I will probably have to come up with a way to replace that before September.

Anyway, I wanted to share my experiences with anyone else who may be considering a solar setup for remote camping. :elkgrin:

 

[Bear in NM]

Martin,

Thanks for the update. We have a few things in common. Namely, I am familiar with Wellington, having lived in Conifer for 10 years. I am now in northern NM, but have the same issues with trees and camping. I have a 75ah setup with a 135 watt panel, and on my last trip to the ranch (and first for my system), I had to piddle with my panel just a little. Not a big deal, but I had full sun. We have the monsoon flow again here, so I will be doing some testing here at the house, with clouds.

I too had issues with the big panel and transport in the back seat of my Chevy Avalanche, but have addressed that now with a yakima rack on my rear bed panels. I have a quick setup system for my big 135 watt panel, and when I add a second, hinged to the first, besides the weight, they should ride just fine on my yakima rack. I have a nifty off road trailer that was set up for my Jeep, and now pulling it with the AV, I am going to look at it next year for either making a proper tent trailer out of it, or do one of the pop-ups or teardrops. At that point I will will be able to easily add more ah capacity to the trailer. Having the solar and controller side sorted out now, will sure make it easier to expand or modify.

One of the things that I am trying to keep perspective on is fiddling with the system. Up at the ranch, we blow through a lot of ammo shooting guns, or folks will hang out and read, or do other chores around the place. I view the solar/12v system as just another fun thing to do, while camping. And I have not sold any of my coolers, so as much as it is fun and useful, I am not permanently wedded to it.

Good luck, and have fun with it, and finding that single tree that resides on the Colorado/Kansas border.

Craig

 

[Martinjmpr]

Craig: Thanks for the input. Are you worried at all about attaching your panels to something rigid like a roof rack though? I would be concerned that hitting a big bump might transfer some shock to the panel and break it. Or is yours in some kind of padded case?

For those interested here are a couple of pics:

My panel on the ground in the spotty sunlight:

My low-tech solution for keeping the controller out of the rain: Invert a plastic box and cut a hole in the side for the wires. HF dead blow hammer keeps the cover from blowing off (it got very windy when the afternoon storms blew through) and also is used to pound in stakes for the awning and pop-up. Not glamorous but it works. A better solution will be forthcoming...

As we say in the Army: "If it's stupid but it works, it isn't stupid." :sombrero:

 

[dwh]

You have to aim it at the sun. If the photons strike it at an angle many will ricochet off the glass instead of driving in and crashing into the electrons in the solar cells.

It's the photons knocking the electrons around like billiard balls that makes the thing work.

The main advantage of a ground deployed panel over a fixed mount is the ability to aim it face on to the sun.

For wire get a 100' roll of 12-2 wire for low voltage landscape lighting. 50 bucks at home depot. Since you're only talking 5 amps with that solar panel, you'd be fine using that same wire on both sides of the controller, though I'd keep the wire run on the battery side to maybe 10' max.

Also be advised: Due to the way solar panels are wired, shade on even ONE of the thirty or more solar cells in that panel could cause a drop in amperage output by either one third or one half depending on how the panel is wired.

 

[Bear in NM]

Martin,

I had that discussion with my local solar shop. I was told that the panels are not what you would call fragile, as they have to tolerate some amount of hail. These are the panels they roof install here in northern NM, and we do get hail. Not baseball, but most certainly pea to marble. But, I use a small amount of weather strip foam in my u-channel and clamp side to give a little cush. And the bed panels on my Av are not super rigid. When i was at the shop, they showed me a van out back that had them rigidly mounted with no ill effect, and in looking at the van, I know where they live. Seriously rutted roads out that way. I do not have any serious off-road bounce on it yet, so we shall see. I have 52 watts of portable back-up in my case, so even if the big one were to break, I would not be completely sol.

The monsoon flow we have had the last couple of days would have been a challenge for your hammer. It's been nuts. Looks like a nifty little trailer, and I too use an easy up, when I can. Hope you packed the lemon and butter for the trout ;^)

Craig

 

[Martinjmpr]

Martin,

I had that discussion with my local solar shop. I was told that the panels are not what you would call fragile, as they have to tolerate some amount of hail.

I would worry more about flex than hail, though. Still, it's good to know they're not quite as fragile as I'd feared. Either way I need to come up with a better way to carry ours. I wish someone made a nice case for a panel like we have but in the long run it may be cheaper for me to just bite the bullet and get a folding, suitcase-style panel.
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The monsoon flow we have had the last couple of days would have been a challenge for your hammer. It's been nuts. Looks like a nifty little trailer, and I too use an easy up, when I can. Hope you packed the lemon and butter for the trout ;^)

Craig

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No trout since this lake was all catch-and-release but we had some juicy steaks and a chili cookoff with 6 competing entrants. Winning entry was a white chicken chili that was amazing!
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We do a lot of cooking on these camping trips which is why it's so important for us to keep the fridge running!

 

[Bear in NM]

Martin,

I am in the same boat. If this continues to work, I could see the investment in a suitcase style. But my goal is a singular investment into camping, and home backup. But even a suitcase would need a dedicated space that is not subject to load shifting or impact. I guess it comes down to where and how you camp, the roads and the folks and pets that may be in the picture. My dog has been explicitly instructed that any urine on my deployed panel, and he gets no dog bones for the night.

I had forgotten that that lake was catch and release. I knew it was a private facility. And yes indeed, with only one trip and my new fridge, I am really digging the concept. And my days of eating granola and gorp when out in the wilds is way past done. It would take a very long time to amortize the cost of my Arb against ice, but again back to having a home back-up system makes it much easier.

And back to what DWH posted about shade, the inline ammeters that monitor amps from the panel sure are handy, if you do not have a way to track. My dog also has marching orders to not sit in front of my panel. He's 110 lbs, and can really knock my amps down, with his shadow ;^)

Craig

 

[Jakes40]

Thank you guys! I've got a similar setup and I am looking for what size panel I will need. I have 2 12v 65 Ahr SLA batteries in the bed of my tow rig dedicated to the fridge. I will be getting a 24 hr reading with a Watt meter this week. And plan on getting 2 60watt panels and hinging them. I have not desired on a controller yet.