New solar install....

[GeorgeR]

Originally Posted by honda03842

...... For me I would rather 'add an additional panel' than bother with tilting or tracking........
For us the addition of tilt hardware is not worth the effort......

Ditto,
George.

[Sharon G]

George, TG's figures do look very optimistic when compared with that chart. I appreciate that info because I was pretty boggled with his reported results.

Norm, adding another panel does make a lot more sense than messing with tilt hardware.

Thanks to both of you for the reality check. I tend to go overboard on everything, and am really trying to learn that sometimes less really is more!

[bdosborn]

Originally Posted by GeorgeR

Norm,
Optimum operating voltage of your panel is 18V so at this voltage you could boost charging current by about 30% using MPPT controller. Prices of MPPT controllers are getting reasonable for example this one for ~ $27. 12V/24V 10A MPPT Solar Controller WS-MPPT15 | Wellsee Solar Products Manufacturers In China

As with most things, you get what you pay for with cheap controllers from China.

http://www.wind-sun.com/ForumVB/showthread.php?t=9482&highlight=Wellsee//

A good MPPT controller is expensive so it rarely makes sense to use one on a small system, as opposed to just buying more PV panel. Morningstar makes good PWM controllers that only cost a little bit more than than the eBay controllers. Google "Sunsaver" for more information.

Bruce

[honda03842]

Bruce.

I now understand that the strength of a Maximum Power Point Solar controller (MPPT) is designed to maximize battery chargering current. It is basically an intelligent DC to DC converter. It produces an output that takes the energy output of the solar panel and converts it into a new voltage level that will get the most power into the battery.

Maximum Power Point Tracking Charge Controller

Is there some technical reason that you are opposed to the model that George has suggested? I'm trying to learn.

Thank you,

Norm Milliard

[Perry J]

Norm,
My 50w panel and $19.95 controller from Ramsond have never let me down.
I've camped in low temps with the furnace on all night long and when the grand kids are with me we also watch DVD movies until they fall asleep.
The panel was mounted on the front portion of the roof on my 16' Scamp with about 3/4 inch clearance. The only angle was the slight slope of the roof.
With full sun my Group 29 battery was fully charged usually by 11 am, with filtered sun it was never later than 1 PM.
I can understand the need for a more efficient controller if you're running a high demand system.
My suggestion is try you old controller and see if it's satisfactory.
I'll bet it will be all you need.
John

[bdosborn]

Originally Posted by honda03842

Is there some technical reason that you are opposed to the model that George has suggested? I'm trying to learn.

That particular controller is a really a PWM controller but it's being advertised as an MPPT type. Caveat Emptor. Most of the cheap controllers that say MPPT on them are really PWM. You should spend some time at the solar forum I posted the link to as there is a lot of good info there. They test a lot of controllers and post the results.

That being said, I really like MPPT controllers ( I have one) but for a small system the payback isn't there. A 30% increase in array efficiency is only going to happen when the panels are cold and the battery is deeply discharged. 10% is a more typical increase that an RV installation is going to see. 10% of a 40 watt system is only 4 watts but an MPPT controller that actually works is around $150 over a PWM type. That's $38/watt. Even if you did get a 30% increase, that would only be 12 watts or $12/watt. PV panels are currently around $2-3/watt so that same $150 would buy 50 watts of additional panel.

MPPT makes sense if you have a system that has an array size of at least 300 watts or your roof is full and you want to squeeze every last watt out of your panels.

MPPT is also used when you want to run your panels in series for a higher array voltage or you have a panel with a higher voltage. An MPPT controller typically has a higher input voltage than PWM.

Here's a link to my solar stuff, there's a link to a DIY portable solar panel that you might like:

Boxcar Solar

Bruce

[GeorgeR]

Originally Posted by bdosborn

That particular controller is a really a PWM controller but it's being advertised as an MPPT type. Caveat Emptor. Most of the cheap controllers that say MPPT on them are really PWM. Bruce

Thank you Bruce for your opinion, how do you know that the Wellsee MPPT controller is really a PWM one? If you have a document to support your judgment please share it with the forum. Wellsee Company employs 90-100 R&D folks. Manufacturing has ISO9002 certification. I would hope they would know the difference between MPPT and PWM controllers.
George.

Hubei Bluelight Science & Technology Development Co., Ltd. - solar products, solar controller, solar charge controller
Solar Power Products Manufacturer - Wellsee China
Wellsee solar charge controller: PWM or MPPT!

[cpaharley2008]

I feel we are getting off the intent of this post and the installation of a small system on a small fg rv. There is a lot of information out there on other forums, some of which has been discussed here. As with anything, diligent research should be performed in making a purchase. Controllers, solar panels, batteries, tilt vs non tilt, tape vs holes, are all options and subject to opinions. What works for some may not work for others, but at least there have been post several options and alternatives.

[Joy A]

I have a 55 watt panel and a group 27 battery. I place the panel up on top of my trailer while dry camping. I have a 13 Scamp with the large escape hatch over the bed. I can stand on the bed, open the hatch and place the panel on top of the trailer. I drape the wire down the side to the outlet on the side of the trailer. Jim's last two pictures are of my Scamp and the connection.

I have had my panel for some 8 years. Initially I had made a frame for it that would tilt it to a variety of degrees. I found that to be a pain and very quickly discontinued trying to tilt the panel. I took the panel off the frame and made legs for it. So for most of it's life the panel has sat flat on the top of the Scamp. The 55 watt keeps the battery topped off whether in full sun, partial shade or full shade. It has only been the last year and a half that I changed the lights to LED.

IMHO... 55 watts or less should be fine for most people.

[bdosborn]

Originally Posted by GeorgeR

Thank you Bruce for your opinion, how do you know that the Wellsee MPPT controller is really a PWM one? If you have a document to support your judgment please share it with the forum. Wellsee Company employs 90-100 R&D folks. Manufacturing has ISO9002 certification. I would hope they would know the difference between MPPT and PWM controllers.
George.

Hubei Bluelight Science & Technology Development Co., Ltd. - solar products, solar controller, solar charge controller
Solar Power Products Manufacturer - Wellsee China
Wellsee solar charge controller: PWM or MPPT!

George,


Follow this link to the solar forum at Northern Arizona Wind and Sun.

Wellsee MPPT

They may have received a bad unit but it doesn't appear like the unit functions in an MPPT mode or is designed with the expected components of an MPPT controller. Perhaps you've had better luck?

Bruce

[honda03842]

I received my second Sunflex 40 watt flexible solar panel today and attached them both to the roof using Scotch outdoor high bond tape.

I intended to add pictures but Blackberry is suddenly not functioning

[cpaharley2008]

I heard that too much solar will affect your Blackberry-

[GeorgeR]

Originally Posted by bdosborn

George,
Follow this link to the solar forum at Northern Arizona Wind and Sun.
Wellsee MPPT
They may have received a bad unit but it doesn't appear like the unit functions in an MPPT mode or is designed with the expected components of an MPPT controller. Perhaps you've had better luck?
Bruce

Hi Bruce,

Thank you for posting this link. I read all 4 pages of this Wellsee thread and did not found a convincing argument that the tested 60A MPPT Wellsee controller was not working in MPPT mode. The experiment set-up to test MPPT functionality had inconclusive results as stated by other members of this discussion.

I did see the comment of Wellsee being a Chinese junk. I would not be shocked to find out that Morningstar products are also made in China, their company site states that their commercial and engineering offices are in US but their manufacturing location is not listed. MPPTs’ costs of manufacturing is likely very similar to PWMs’ costs. A product price not always follows manufacturing cost, so because Wellsee is less expensive is not necessarily a good argument for questioning MPPT functionality.

I have the 15A Mornigstar MPPT controller on my system and I still like it better than Wellsee because it has a well-integrated remote monitor and a battery temperature monitor, and I was willing to pay for more mature engineering of the Morningstar Company.

George.

[GeorgeR]

Originally Posted by cpaharley2008

I heard that too much solar will affect your Blackberry-

Especially in Europe,

http://www.nytimes.com/2011/10/13/te...-continue.html

George.

[honda03842]

It's really too bad. RIM, creator of Blackberry, has become almost suicidal. Employees have verbalized the problems of their management, the release of non-competitive products, and now a 3 day long system failure.

Actually my Blackberry has been amazingly durable, apparently not the company.

[honda03842]

Finally Blackberry is functioning and I can get pictures.

The two panels are taped down, the wires have been fed thru the roof. The only step left is to wire up the Solar Controller.

[Jane P.]

Originally Posted by honda03842

Finally Blackberry is functioning and I can get pictures.

The two panels are taped down, the wires have been fed thru the roof. The only step left is to wire up the Solar Controller.

That looks so sweet. Please post regularly on how well this is working for you. I'm interested in pursuing new things that work well over time.

[GeorgeR]

Originally Posted by honda03842

Finally Blackberry is functioning and I can get pictures.

The two panels are taped down, the wires have been fed thru the roof. The only step left is to wire up the Solar Controller.

I love it,

George.

[honda03842]

The first picture shows the thru hull fitting. This fitting is normally used on fiberglass boats. It is filled with Lexal.

The second picture is intended to show the thickness of the panel (really the thinness). That is my Scamp door key beside the edge of the panel. The edge can also be seen behind the thru hull fitting.

[honda03842]

I decided to buy this interesting watt meter that can provide data on solar panel performance. This will allow me to compare the performance of my PWM Solar Controller with a MPPT Solar Controller when I buy finally buy one.

The website links to ebay where I purchased it.

Watt Meter tester test tool Measures Amps Watts voltage | eBay

The following PDF file is the manual for the device I purchased.