Solar panels for dummies

**Lesherp** · 03-03-2013, 06:14 PM

I would like to have solar before our big trip in May. We camp a lot where there is no electric hookups and hate the noise of the generator. I think I have read everything here but am not sure what to buy or exactly how it works.

Technology is changing constantly, so I imagine some of the older information may no longer be pertinent. From what I have gathered I will need a couple of panels , brackets to attach them to the trailer, some kind of super adhesive tape to glue the brackets to the trailer, a controller, a way to connect the two (wire) and probably some kind of fuse.

I live in the Pacific NW where there is limited sun part of the year, and a lot of trees. It looks like we will be traveling to the SW in winter and/or spring now that we are retired so we would really like to have solar. I have a generator, but would like to eliminate using it even at home if that is possible. I am for the most part a, get your most bang for the buck kind of guy, even if that means buying something a little more expensive to begin with.

I would appreciate any suggestions as to exactly what equipment I should purchase. How many watts should the panels have? Is there a difference in controllers? Would one better meet my needs? Type of wire. What kind of fuse to use. Has there been any problems with the adhesive tape talked about in the posts?

If I understand correctly power from the panels is run to the controller and it is wired directly to the battery. At this point I get a little confuse as to how it all works. What happens if I am connected to shore power also. Will I need turn one off or disconnect something?

**Bill** · 03-03-2013, 09:19 PM

Lots of good questions. Let me start with some thoughts, and many other members will follow up.

How many watts in the panels? Stay away from the little panels, like 15 watts or 25 watts. General concensus seems to be that two or three 80 watt panels is pretty good. You would have trouble carrying more than that, though it could be done.

Your panels could either be roof-mounted as you describe, or portable ground-mounted. Roof-mounted are easy to use, but depend on parking your TM in a spot that will be sunny all day. Although you get lots of electrical power, your trailer becomes uncomfortably hot inside, especially if you are camping in the desert. Ground-mounted enable you to park your TM in the shade, moving your panels into the sun and pointing them south no matter which way the TM happens to be facing. Lots of discussion in the Solar Power forum.

You need a controller, whose function is to stop the solar system from over-charging your batteries when they are full. A simple and cheap controller is perfectly adequate for the small systems we are discussing. More expensive controllers (called MPPT) will extract more charge from each hour of sunlight, but for a small system are so expensive that it is cheaper just to buy another solar panel if you need more capacity.

You can run the solar charger system and any other charger at the same time. No need to think about switching one off and another one on, etc.

Try going to Arizona Wind and Sun http://windsun.com/ for a lot of good info. Although they sell solar setups from an associated web site, their mission here is to educate potential solar users so they know what to buy.

Hope this helps.

Bill

ThePair · 03-04-2013, 08:19 AM

I don't have solar, I don't plan in the near future on getting it -- no need for me, currently.

However, I would look at these guys: http://shop.rvsolarnow.com/RV-solar-Kits_c8.htm

Why? They're solar-in-a-suitcase systems, which look like they'd need minimal modification to wire into a battery (with a disconnect). Portable = aim it at what little sunlight you can find, without having to worry about parking the TM in a particular location/orientation. Don't bring them when you don't need them, etc. Not too pricey, either, best I can tell. Expandable, if you find that your initial estimate of need isn't enough, you can add on another portable panel.

It's something I would seriously consider, just passing along another option!

(again, I don't have solar and have had no dealing with this company, just thought the product showed promise for our kind of set-up)

03-04-2013, 09:08 AM

+1 on windsun.com

Very unbiased info with simple to understand explanations

03-04-2013, 11:29 AM

The RVSolar site looks very interesting. As someone with the factory solar panels, there is a real need to have a system which can be tilted and moved around. The sun is rarely where you need it! As an aside, it seems I remember someone who designed and roof-mounted their own system a couple of years ago. The instillation seemed to be interesting at the time. Maybe a search would find it...

**Lesherp** · 03-04-2013, 01:46 PM

I am thinking that the portable unit might be the best way to go.

It seems like set up time would be minimal. The chances of being able to have your panel in the sun would be greater. With the extension cord you would be able to place and orient it up to 40 feet from the trailer. I talked to the manufacture and the only difference between the economy and pro is the controller. The pro displays battery voltage, output, amps, total amp/hours produced, and percent of battery charge. I think my clipper monitor will do most if not all of that.

I was concerned about leaving the panels unattended. The handle is attached with tamper proof screws so a security cable can be used. The alarm padlock that comes with the pro can be purchased for $25 if wanted. The mounted units would be a little more theft proof but I think this would be acceptable a lot of the time. When it isn't just use them when in camp.

I would not have to worry about hail or cleaning that were the negative factors I saw in roof mounted panels. The only advantage I see to mounted is charging when traveling.

**Bill** · 03-04-2013, 01:51 PM

Quote:

As an aside, it seems I remember someone who designed and roof-mounted their own system a couple of years ago... Maybe a search would find it...

Most of this board's experience with roof-mounted panels goes back to Rocky_Mtn_Ray, who first did it in 2003. There is more recent experience with roof-mounted panels, and a Search of the Solar Power forum will indeed turn it up, but pretty much all of it goes back to Ray, who researched it intensely.

http://www.trailmanorowners.com/foru...ead.php?t=1034

I have to agree that in very many cases, portable panels will do a better job, for the reasons stated. There are a lot of discussions on this topic as well.

Bill

**Lesherp** · 03-04-2013, 05:03 PM

From reading it seems that it is best to have the controller as close to the battery as possible. Is this a drawback of the design of the CEA units? How important is it?

03-04-2013, 07:23 PM

Most panels put out around 17V taking into account loss between the panel and the controller. The controller then takes adjusts the voltage down to the proper charging level. Any drop between the controller and battery ( caused by wire length between them) results in a further drop in charging voltage that impacts charging capability. If you park your TM in the shade and want your panels to be efficient, I suggest portable. A simple inexpensive collapsible support can be built from PVC.

scrubjaysnest · 03-05-2013, 06:02 AM

Quote:

Originally Posted by Lesherp

From reading it seems that it is best to have the controller as close to the battery as possible. Is this a drawback of the design of the CEA units? How important is it?

It will only be a drawback if the controller doesn't have remote temperature correction. To get the best out of the system use the largest wire you can afford, no smaller then 10awg for a 40 foot run. If the controller has built in temperature correction then locate it within inches of the battery's for best results.

+1 for the windsun.com site