I am modifying my battery installation to include the ability to connect Solar Panels for recharging. My Fiber Stream has it's battery box accessable from the front of the trailer through a vented hatch door.

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A previous owner added a cord hatch to the access door.
What could this be for?

I think I found a use for it...

I bought a Solar Charge Controller on eBay and installed it to the inside of the access door.

Click to view attachmentClick to view attachmentBattery (Red/Black block)
Now I can feed the Solar Panels' wires through the little hatch in the larger access door and connect them to the charge controller next to it and close the door.

Edit Note*
I corrected the errors in my wiring and replaced the photograph and wiring diagram.
Thank you, Gina!

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While I was at it, I made the Battery Wires long enough to set the battery on the ground while it is connected to make servicing easier.

I like that hatch idea.

Fred, are you running your car charge line into the controller?

If so, you will damage the controller. It can not handle that type of current.

Never plug anything into the input of a solar charge controller but a solar panel.

OK. I will change that.

from the owners manual from one of my units, but I have seen the same for others



This also explains how the unit cuts off. Would hate to see what happens when your alternator or battery has a dead short underway.

My solar panel charge controller doesn't short the input like Gina's (it just opens a relay) so it wouldn't be a problem in that respect, but I agree that connecting the power from the tow vehicle on the output/battery side of the controller rather than the input/panel side would be a good idea anyway - the tow vehicle does its own regulation.

Slick setup, Frederick!

Yep, the battery should be the common point for all charging arrangements that I know of (Converter, battery charger, battery maintainer, generator, tow vehicle, solar and hamster in a wheel).

I purchased the solar panels from Harbor Freight.

It comes with a rather large charge controller that I am not going to use in the trailer, since I have already installed one inside the battery compartment of the Fiber Stream.

I did buy 2 extra items:

72" x 1.5" Aluminum Piano Hinge
12' of 3/4" diameter Yellow Heat Shrink Tube.

I cut the Piano Hinge into two 3' pieces.

I had to carefully drill offset screw holes in both the hinge and the edge of the Panels' aluminum frame so not to damage the glass part of the panel. I attached the 3 panels together, with the hinges facing opposite directions. Then I bundled the wires together into 1 cable with the heat shrink.

Now the panels stow compactly. I show them folded, along with the collapsed angled mounting frame:
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My next project will be to build a carrying case, or box, to store them in.

I open the panels and assemble the frame:
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... and lay the panels into the frame. There are pins in the frame that fit into receiving holes in the back of the panels.Click to view attachmentClick to view attachment

And then I connect the panels to the charge controller.
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Now I close the battery box, and Wa-La!
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Looks good!

OMG Fred it's a thing of beauty! You'll have to let us know how those panels work. I've looked at them several times but didn't have the spare change. They seemed like a great deal but like you I thought the controller was heavy and big and the included lites were "interesting".

How much do the panels by themselves weigh?

30 pounds together; 10 pounds each How did you know I'd weigh them?

Does anyone use (READ : do I need) a fuse and/or ground for a 12V solar system? It feeds a 100Ah deep cycle marine battery.

Also, while I'm on the subject, how do I check the ground on my 120V plug-in?

Darren,

You will be grounded by default if you wire your controller correctly. The controller OUTPUT connections go straight to you battery terminals + and -. You panel lines go INTO the controller inputs.. + and - . You are now grounded if the battery is (and I hope it is!)

You could put an inline fuse on your solar lines, but your controller will probably handle 5 amps or more if you get a decent one, and it is doubtfull you will come anywhere near that just trickle charging.

The story would be different if you are trying to run items from your panels, but during the day.. when the solar is doing it's charging job...when you don't need lights.. you get the picture.



Trailer cord or park outlets?

on sale at this moment for $199.99 ( lets me out, heheh), i think i'll stick with my gen.

Hey Gina,

I'm starting from scratch. The old 12V system in my Boler is toast and doesn't seem to be wired to/from anything! Just a single 12V female socket near the top right corner of the cabinet above the sink .. pretty much just floating there. Not even a battery!

So I've bought a 57W panel array (Coleman, from Cosco - nice product if anyone's in the market!). It comes with a 5A charge controller, I bought a 100 Ah deep cycle marine battery. Now I have to figure out how to install it all - from scratch.

I know I need a bunch of 12V female outlets (I'll install them into the sides of the sink cabinet unit to power devices from the guacho or bed/dinette) which I'll run direct to the battery. The battery will permanently connect to the controller. The array of course will be quick-install to the controller on arrival at camping.

The reason I want to do it all 12V is that we aren't 'check-in campsite' campers. We are out in the boondocks campers so we really want to be completely self-contained.

I also have a 400W inverter which I will plug the main trailer electrical into (to power all 120V devices and sockets) on the rare occasion I need it. (In fact all we really use is a small all-in-one portable TV/DVD player/Radio/CD Player. We do have compact flourescent lighting too, but that will only be used when docked - we have 12V lights as main system- these are LED lights that plug into a car lighter socket but they work great!)

I guess I'm trying to get a feel fo what else I"m missing. Grounding for sure. This might sound dumb, but I guess I don't know how to ground the 12V battery. What kind of wire, how to connect to battery and how to ground it.

I think the 120V is grounded to the bolt that attaches the refridgerator to the frame. ( ? sound right?) I'd like to test this though - is there a quick way to test a ground?

Sorry to get off-topic, but any help would be appreciated!

Darren

It seems to me, and I'm no expert...if your 12 volt system isn't grounded properly nothing will work. I'll have to go home and look how my Trillium's 12 volt is grounded(I have been home and looked, only grounding comes from (-) post on battery), I know where the 110volt is grounded, I can see a ground wire to the frame in the back under the street side bench. As far as 12 volt wire goes, as I am cleaning some things up I am using 12 gage wire for my main runs, and lesser gage depending on what I am connecting. For my 12 volt outlets I will use 12 gage wire. My trailer has a very simple electrical system, sounds much like yours. I have 2 110 volt plugs and 1 110 volt light. The 12 volt consists of 3 lights, and a run to the fridge, it came with no battery.

I'm thinking about it now...maybe my ground is coming from the battery??? When connected it has a negative pole, and the same when connected to the tow vehicle, ground comes from the vehicle.

Hmmmmmmm .... I dunno,

First, a lot of people use the term 'neutral' and 'ground' to mean the same thing, and from what I gather, they're really not. The neutral handles the flow of current FROM devices that have used up power from the live wire. It returns back to the battery to complete the circuit and for re-energizing. The ground wire creates a 'path of least resistance' and dissipates any extra current - created by eg, a surge - and stuffs it some place safe - usually the ground.

So, your 12V would - like any other system - work fine without a ground, but if there is a short circuit or surge you could get an unfortunately high current through your lines and either fry your wiring, devices or worse, yourself.

Having said that, the trailer wiring diagrams I've seen only show a ground at the hitch's electrical connection, not from any battery. I don't know if these are generic diagrams for all types of trailers or designed for RVs with on-board 12V battery.

So, I'll be installing a single connection from the battery to a terminal block to connect all 12V devices/lighter socket plugs. I'll be putting 5A automotive fuses on those. And I'll need to ground the whole setup.

I know that to ground it, it would have to go FROM something TO the frame ... but what is the 'FROM' part of this equation? A tie from the neutral? The battery's negative terminal?

You probably have a valid point, the fail safe point may be the fuse that is in the "power" line (black wire) back to the battery. It seems to me if my memory is working, the guy who wired my vehicle indicated that the fuse would protect the electrical system if a short or overload occured.

I would think that the ground could go from the terminal block to the frame, that way the entire system would benefit from the ground. From the terminal block to the battery would have a fuse in the power wire, protecting the battery.

There are a few clues shown in the manuals that you can see under Resources~Document Centre~Manuals that you can get at from the home page on this sight. For instance, the Scamp manual shows an in-line fuse on the black (power) wire from the battery. You can also get some idea of the guages and fuses used too.

Brenda & Dave and Darren
I think you may be starting down a tricky path here trying to compare D.C. and A.C. electrical systems in your trailers.

These systems are seperate and dis-similar aside from the fact that they both control electrical items.

In a D.C. system there is a 12volt positive and a negative or ground cable.

All 12volt circuits run on these two wires.

For reasons I will never understand there are two different conventions used to mark the wires and they are exactly opposite.
In some the red is 12v positive and in some the black is 12volt positive?

If you buy a cheap multi-meter you can easily determine which you have for any given 12vdc circuit. They are also very handy for many other uses and under $20.00 at a home center....get one.

In a trailer you can ground a 12vdc outlet or fixture to the trailer frame and then just run a single conductor wire to the Positive load. Most small trailers come wired like this, but I always just run two conductors with a dedicated ground to each fixture. Most wire is two conductor anyway and it is a lot more reliable to run the ground on a wire rather than through the trailer frame especially for us as the trailer body is non-conductive fiberglass which can make frame grounds unreliable.

It is then a simple matter of running your load wires to the battery directly or if you want more control through a switch or switch panel so you can control them from a central point.

Likewise you will need to charge the battery and you can connect the charger directly to the battery too. It may be Solar or it may be a house powered charger but either way it will output 12volts DC to charge the battery.
Some of these will also supply enough 12volt DC power to run the trailer while your battery is charging. some will not.

This is a very simplified overview for sure but 12volt DC systems are fairly straightforward really.

The 120volt AC system is like a residential house system and the three wires are not directly comparable to that of the 12volt systems and should not be interconnected directly!

There is a device many trailers have and that you can add called a "Converter" that will supply both 12volt DC power from 120volt AC power and charge your battery and supply 120volt AC power when plugged in.

They can act as a central point for all of the wiring and simplify things a lot.

I hope this clears up some of it and there is a wealth of other info out there on this site and many others.
I recommend a West Marine catalog as they include basic info on all of these systems and feature equipment to make it all work in a single free catalog.

Remember if you don't know,please find out. This stuff can be bad if done wrong.

And Have Fun.

Ed

You are correct Ed, I often have to look at the wires several times because they are confusing, the positive does come down the black (or red wire) and that is typically the one with the in-line fuse (I have corrected my posts above). The white wire is the neutral.

In my Trillium there is no converter, the two electrical systems are completely seperate and there is no comparing the two.

Thanks for setting my colours straight.

Dave

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Yes, that's what I paid. Most of the other local retail establishments around here sell each 15 watt panel (different manufacturer) for over $100, so I feel I got a deal. I only had to wait 4 months from the last time Harbor Freight put them on sale, regular price is $250.

Ok! And now we all agree ..

Here is my setup
Battery positive terminal usees 8 guage wire to circuit breaker, thus fusing the entire system
Three 14 gauge wires coming to each of the three 12V accessory outlets on the trailer
These are tied together with the return (ground/neutral) which goes to the (-) terminal on the battery, which is tied to the frame.

Sound good??

I suppose I didn't say clearly enough what I was trying to.

In a 12volt D.C. system there is NO NEUTRAL wire.

The Ground wire is not at a neutral potential,it is at a ground potential. There is no debate,that is why it is called Ground and not Neutral.

In a 120volt A.C.circuit the Neutral and Ground are also not at the same potential.

I am not explaining here how A.C. power is produced but there is a safety and danger issue involved here by not understanding these differences.

In your 12v DC system the GROUND is part f the circuit itself.

In your 120v AC system the GROUND is more of a safety to make sure there is a safe discharge path to ground in case either the HOT or NEUTRAL wire become crossed somehow or grounded.

There is voltage alternating between the HOT and NEUTRAL 60 times a second(in America)
and grabbing either at the wrong time can kill you dead.

The GROUND of both systems may be tied to the same place on the trailer frame but I hope and pray that no one ties the NEUTRAL to the frame too by accident,

I am not trying to hijack this thread but it scares me a little to read some of it too.
Of course this is over simplified but they are not the same at all.

Ed

Thanks again Ed, I only called it neutral because it connected to (-) post on battery , I have no problem calling it Ground.

Sounds good, you were in a prior post using a terminal block to bring the wires back to a common location, then off to the battery, correct?

Wire your charge controller DIRECTLY to the battery.

Ed, you are not over simplifying anything. In this instance, simple is the proper way to do it..

it's not rocket science.

wire like this and you have done it properly, no worries, nothing in between.

Panel +/- to charge controller INPUT, Charge controller OUTPUT to +/- on battery. Done.

Frederick L. Simson ! Thank you so much for this post on this cool mod! I've been toying with the idea of a generator, but would rather work with solar, and this is just what I needed to know!!!

I was, but after some advice from the AutoParts guy, here is what I now have on the live-side of the battery (the charge side of the battery is unchanged)

8 guage wire from battery to a 20A curcuit breaker (protects whole setup at once)
From the protected side of the curcuit breaker, three 14 guage wires to three accessory outlet sockets. It essentially replaces the need for the block.
Each one is tied into a ground wire heading back to the (-) terminal on the battery, which is tied with 8-guage to the frame.

Any concerns ... or do I have it right now???

Darren

Thank you, Gina!
The guitar case works perfectly.
Click to view attachmentClick to view attachment

The case full of solar panels even fits on the tongue, behind the propane tanks. I just gotta figure out how to strap it down for travel.
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Until then, It'll ride inside.

Wow, and you managed to keep one side of the plush. Cool.

That case is the perfect size. It was about an 1/8" to narrow for mine.

I would plan on keeping it inside for travel Fred. Turn your back for 2 seconds and that "Guitar" will walk faster than you can say "Boo". The thief will be disappointed they didn't get a pointy Headed Jackson, but thats no consolation once the panels are gone.

The case is also NOT waterproof.

I kept BOTH sides of the plush.
I just removed the plush lining from the styrofoam after I removed the styrofoam from the case. Right now the plush is laying loose, but sometime I plan to reglue it to the case itself.

The next owner of my 13 foot Boler mailed me to report his first camping trip was successful except for the fridge fire they had. Apparently it happened because the +12V line of the fridge had rubbed together with the 110V line and wore through the insulation. The 110 wasn't plugged in and the fridge was running on propane but the 12V line was still live... The insulation burned and caught the fridge on fire. Why am I bringing this up in this thread? Well, when I had refurbished the trailer, I added a breaker panel for the new things I added into the trailer (water pump, LP/CO detectors, lights, propane solenoid) and upgraded the wiring from the battery to the panel. So there was a nice 12ga wire coming from the batteries to the panel, and then subsequently 16 gauge to the fridge. The end result was that when the fridge wire insulation shorted out, the 'fuse' because the 16ga wire and that's some fuse allright...

My point is, install a fuse or breaker or something right on the main feed from the battery, and every other circuit in your trailer. If your battery is outside, don't put a fuse out there; it will corrode and act intermittent. Auto manufacturers use a 'fusible link' which is a short bit of wire with inflammable insulation and rated to a specific amperage (usually 30A). This short piece of wire goes between the positive side of the battery and the rest of the vehicle wiring (that isn't the starter)... All other fuses are mounted downstream of that. There's no reason our trailers should be wired and differently, except that our manufacturers are cheap and cut corners wherever possible... So, on this next trailer, I plan to add some fusible link between the batteries and the feed line. I imagine it should be available from auto dealers for relatively cheap..

Adding solar power to our trailer is high on our list. I've bought a used 13"x48" Siemens/Shell 50w panel that I plan on permanently mounting to our roof, tucked between the centerline ridge in the roof and the awning housing where it'll be difficult to reach or see. These panels are known for providing good output even when the angle of the sun is far from ideal; hopefully it'll provide for all out dry-camping electrical needs, but if it turns out we need a little more juice for times we're parked under a tree or such I'll probably buy a set of Harbor Freight panels like yours, too.

--Peter

Alas, I am the guy that Herb is talking about. The shorting of the wire did cause quite a bit of damage to the fridge in what seemed like a short time. From smelling the smoke to putting out the fire was probably 1 minute or so. In this time the fire grew and melted all the wires and even started to scorch the bottom of the drawer above the fridge.

As you can read from another post by Herb, these batteries, while low voltage have some serious amperage and with the right equipment, put out enough juice to weld steel.

Well the fridge is toast (ohh what a stink) so thats out and replaced and I've now added a fuse to the (+) lead of the battery to hopefully eliminate the chance of this in the future.

One question for those more electrically knowledgeable... What size fuse should i be putting on this wire? Presently i have a 15A fuse, but ive seen people recommend anywhere from 5A to 30A. As I'm only running lights and a water pump and perhaps the odd cellphone charger, am i in the right range? I turned everything on (including the fridge) and the fuse didn't pop so I think I'm okay.

The size of fuse is dictated by one of two things. The first is the size of the smallest wire on that circuit, the second is the maximum number of amps you think that circuit could be called on to provide.

In the case of the main charging circuit running from the battery to your fuse panel, the maximum load could (possibly) run is the maximum the wires can carry, so you fuse for the wires and skip all the adding and multiplying you might do for the other "device" circuits. My rule of thumb for 12v wiring is to use

20A fuses for 10g,
15A fuses for 12g,
10A fuses on 14g,
05Amp fuses for 16gauge wire.

Something to keep in mind is thinner-gauge wires (with higher numbers) experience a drop in voltage as the amps they are carrying go up. Basically the volts lost to the resistance of copper wire doubles with every 2g increase in diameter. I'm assuming it's a rare thing when you want to draw the full rated amperage of the wire, and that you'd rather loose energy from your battery than blow the fuse when that happens, so I'm suggesting fuses to protect the wiring, not transmit energy most efficiently or protect the appliances connected to those wires.

If, on the other hand, you have an appliance that regularly draws a set number of amps you'll probably want to use a heavier gauge of wire to reduce energy losses to that appliance and fuse that wire so the fuse blows if your appliance suddenly starts drawing way more power than it should. So, say you have a five amp appliance on its own circuit; you might want to use 14 gauge wire (instead of 16) to keep voltage and energy losses down but use a 5 amp fuse to protect the appliance and prevent the smaller-guage wiring within the appliance from catching fire if it shorts out.

--Peter

I agree with, I think it was Gina, that this is not rocket science.

I've had my panel for 3 years now and I simply ran 2 wires from the battery to the solar controller. 1 negative and 1 positive with an inline fuse. Then from the solar controller I ran 2 wires to a jack on the outside of my trailer. 1 positive and 1 negative. I added a plug to the solar panel wires and simply plug my panel in to "charge the battery".

Nothing runs off this circuit, it simply charges the battery. All DC appliances run off the main DC circuit in the trailer as normal.

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On sale for $199.99
now until June 11, 2007
at Harbor Freight

How is the system working for you Fred?

The voltage coming from your solar panel is highly variable, depending on, of course, the sun. This is almost certainly unlikely to be anywhere near the voltage your battery wants to be charged at.. At worst, you will shorten the life of your battery (I measured 19V coming off my panel yesterday in the noonday sun) and at best, you won't be actually charging your battery... Just because your panel is plugged into your battery, doesn't mean it's doing anything.

A charge controller is much cheaper than a new battery.

My panel came off a sailboat. 50W. I installed a charge controller (small yellow gizmo) from Camping World-$30.00. I didn't put a fuse in the line to the battery. Couldn't see why.
It's been cooking for three years- no overcharge and the green light stays lit. It's on the roof out of harms way. It's not real fussy about alignment to the sun.