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Legacy Posts 08-19-2003 07:37 PM

Casita Solar!
After dry camping on a previous trip in our 17 foot Casita Liberty Deluxe and coming up short on power, we decided it was time to look into solar power to replenish the juice we use.

A second battery was also something we decided was necessary. Considered using two 6 volt Trojan golf cart batteries wired in series for 12 volts, with the second battery in a battery box that would vent to the outside through a tube.

Decided instead on a sealed 12V AGM battery that can be installed anywhere without concern for spillage or dangerous gas emissions, in addition to the house battery that stays in the outside access compartment. <img src=>

The AGM battery was expensive, but it lasts about twice as long as a really good lead acid battery, can handle the abuse of accidental overcharging and needs no maintenance. It fits nicely in the compartment below the furnace. One other good thing about AGM batteries is they can handle temperature extremes much better than lead acid batteries.

Our power use involves running the water pump occasionally, minimal lighting, the Fantastic fan all night long if itís hot, and then satellite TV for a few hours per day total -- unless were having too much fun without itÖ

We really donít want to drill holes in the Casitaís roof, so we canít drive down the road with our solar panel on the roof, charging the batteries as we go. But we may reconsider at a later time.

Legacy Posts 08-19-2003 07:41 PM

Routing wires
Thought it a good idea to have the option of connecting a solar panel(s) at both the roof level and ground level or both at once Ė that way the cables are less obvious to passers-by. We went with quik-disconnect fittings rated up to 50 amps Ė more than needed but rugged and reliable.

We can put the panel up on the right side of the Casita easily, with it secured by the awning brackets, a bungee cord or a sand bag as needed. The wire connection was routed through the black water vent , parallel to the vent pipe, in a Ĺ inch water supply pipe. It exits to the compartment under the stove and wires up to the charge controller.
<img src=> <img src=>

Legacy Posts 08-19-2003 07:42 PM

ground connection
For the connection to a solar panel that is situated on the ground, the shore power access door is perfect.

<img src=>

Legacy Posts 08-19-2003 07:45 PM

Charge controller
We installed the charge controller (which keeps the solar panel from overcharging the battery or batteries) into the compartmentís access door itself, because we donít like the idea of cutting unnecessary holes in the fiberglass and we figure we could replace the access door easily should we later decide to sell the trailer without the solar option.

The wiring is secured to the back of the access door to keep movement from affecting the connections to the battery or controller. Our controller is a ASC Mark 15, allowing for up to 15 amps input from multiple solar panels.
<img src=>

Legacy Posts 08-19-2003 07:49 PM

Solar Panel
The solar panel for now is a 75 watt Shell brand panel. This panel measures roughly two feet by four feet. It provides about 4.5 amps per hour in full sun, and thatís about right for a small trailerís needs, unless you use more power than most people. Of course, a couple cloudy days in a row change everythingÖ.

The panel travels bungeed upside-down on top of the double dinette table, with a blanket under it for cushioning. Upside-down so the panel isn't generating any charge while not connected to the controller.

I designed and built the adjustable frame, using angle iron and some other raw metal pieces, welding the corners. I love my little Lincoln wire-feed welder Ė itís paid for itself several times over already! I could have ordered a frame easily, but I wanted it sized exactly for this particular solar panel, and I wanted the ability to route a lock cable through it for casual-theft-prevention.

Holes in the support bars every inch and a half allow adjustment for the sunís position Ė not totally critical but a good idea unless you only camp in summer months when the sun is high in the sky.
<img src=> <img src=>

Legacy Posts 08-19-2003 07:52 PM

Shop around for your gear Ė even though most of the dealers on the web donít stock much gear and use the same distributors to fulfill orders, prices are all over the place.

Whatever you do, donít be intimidated by solar power Ė the panels are warranted for a very long time and itís not that hard to put together a good system. One that will reward you for years and not irritate your camping neighbors -- like a generator often will.

Of course, the trade-off is the use of an air conditioner, and for all practical purposes, a microwave, hair dryer etc., which draw too much current for a small solar power system.
<img src=>

Legacy Posts 08-19-2003 08:03 PM

Hi Tom
Thanks for the info-Your job looks ok to me.I like way you feed your wires around:wave

Legacy Posts 08-19-2003 10:02 PM

Way to go, Tom!


Legacy Posts 08-19-2003 10:54 PM

Mind if I ask?

I put several solar pannel on my roof but didn't yet buy that neat little regulator/controller.... How much did that cost? I've no doubt you found the best price...

my three pannels total rate 15W. probably more like half that in ordinary conditions. I have it hooked directly to battery with a diode to prevent drain. I'm not sure that I need a controller as for a deep cycle battery my average max one amp charge is like a trickle. I think.

Very nice job on your outfit.

Legacy Posts 08-20-2003 05:40 AM

Nice job Tom!

I have a question ... could you please explain all the various wires going in and out of the charge controller (in terms someone as dumb as me could understand!).

Obviously positive and negative wires .. but what runs to what?

Do solar panels need to be "grounded?"

Legacy Posts 08-20-2003 07:55 AM

to control or not
Hello Tom,

The charge controller came from - it was 79.20, a fair price.

I've been reading conflicting information on when you need a charge controller. Here is one explanation I came across that seems reasonable:

If the maximum current (amps) is less than 1.5% of the overall battery capacity (measured in amp hours), a controller may not be necessary. For example, if you are charging a 12 volt 100 amp hour battery with a 21 watt panel (max power current = 1.5 amps), a charge controller may not be necessary. Generally, using a controller in the system is encouraged as modern controllers can regulate the charge rate and optimize the charge on the battery.

So it appears you are o.k. without one, but such a complex subject as math isn't my strong suit -- remember I'm a welder after all! :laugh :wink :lol2

I did an internet search for Do I Need a Charge Controller, but as I said, there are differing formulas out there.


PS - I love your very kewl trailer! :thumb

Legacy Posts 08-20-2003 08:09 AM

Hi Charles.

The wiring is actually quite straightforward - the charge controller has terminals for Solar Array and Battery connections - one each for positive and negative.

In our case, I have two sets of Array wires tied in there; one for the roof connector and one for the ground connector (the connector that comes out at the shore power access door).

The Battery connections - one positive, with an in-line fuse between the controller and battery - and one negative, with no fuse needed.

I used 10 gauge wire; some folks might go with the thicker 8 gauge.

I was told that an RV installation doesn't need grounding. Maybe someone (who isn't a dumb old welder like me :crazy-ii ) can weigh in on why that is true. Or false. :shg

Legacy Posts 08-20-2003 08:32 AM

Battery switch next
I rushed our solar installation in order to have it ready for a trip to North Carolina's Outer Banks last weekend, and there were a couple things I ran out of time to complete.

The way I have it set up right now, the AGM battery only powers an inverter for TV and satellite receiver. I have added a separate duplex electric outlet above the TV stand <img src=>
that connects to the inverter located next to the AGM.

For us, the possibility of dozing off with the inverter left on is too high. :o :zz :o So we added a lighted switch between the power supply and the inverter, so that the inverter reminds you when it is on. <img src=>

In our case, the regular (house) battery does everything other than power the inverter.

The solar charger isn't connected to the house battery, so I don't have a convenient way to charge the house battery when boondocking. Yet.:duck

What I need now is a 1-2 battery switch (actually, make that two of 'em). I want to have it set up so that I can charge one battery at a time with the solar panel, and have the option of using either battery for the inverter or house needs. So all the options are open.

It's still a work in progress - but the shakedown at the Outer Banks didn't reveal any real big problems. Just a few things to refine! :loltu

Legacy Posts 08-20-2003 08:48 AM

I see ... I got confused when you said "ground connection." You mean when you place the solar panel on the ground, you plug it in via the power cord door ... when you place the panel on the roof, you use the "roof connection."

Ground has nothing to do with grounding.

Legacy Posts 08-20-2003 08:49 AM

Who's watching the Koi while you're doing all this camping? Can I come fishing?:)

Legacy Posts 08-20-2003 08:55 AM

:o <img src=>

Please leave my babies alone!! :E :E

Legacy Posts 08-20-2003 09:01 AM

Not so fast, Chuck!
Here's the catch:
<img src= Guard.JPG/>

Legacy Posts 08-20-2003 09:06 AM

<img src= in the Yard 4-242.jpg/>

Resident 'floor Gator' - she can make it to the fence pretty quick! Can you?

Legacy Posts 08-20-2003 11:04 AM

I know this thread got a little off topic (because of Koigaritas) when it was supposed to be about watching telly with no hook-ups. Solar power is great - and it worked pretty good, too! Too bad the New York feed on satellite was out because of the blackout. :E :E

Legacy Posts 08-20-2003 01:06 PM

battery switch

Great installation! :)

I found a 30a double throw switch with a center off at an auto accessory shop, in with the road lights. Radio Shack didn't have anything like it (or I didn't find it).

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