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Solar panel mismatch

Feb 14, 2014
12
Beneteau 331 North Fort Myers
I have a 90 watt SONALI solar panel connected to standard lead acid batteries via a Sunforce 30 Amp Digital Charge Controller set up by the previous owner on my Beneteau 331. I would like to add another panel, but I am told the 90W is no longer available, but an 80W with similar characteristics from the same company is. Comparing panels: (90W 1st & 80W 2nd) - Max Power 90/82.29 W, Voc 22.2/22.56V, Isc 5.48/4.90A, Im 18/18.4V, Max. Series Fuse Rating 8/10A, Max Syst. Voltage 600/700V UL/1000V IEC. My basic questions:

1. Would the 80W connected in parallel with the 90W create any problems for me. 2. Would the 30A controller handle both OK? Any relevant help will be greatly appreciated, keeping in mind my education with respect to advanced electrical matters is pitiful.
 

arf145

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Nov 4, 2010
430
Beneteau 331 Deale, MD
Sorry, I can't absolutely answer your question, though I'm pretty sure it doesn't matter about the slight mismatch on the two panels, and your controller is 30 amp and the two panels put out maybe 11, so what's the worry there? But I did want to ask where on the 331 you mounted them!
 
Dec 7, 2012
515
Kittiwake 23, Irwin 43 .. Indianapolis / indianatown, fl
hello all

attaching the 2 mismatched panels will not affect the out put or charging of your batteries... make sure you attach the cables in parallel not in series.... by hooking them up in series you will double the voltage.... in parallel the voltage will stay the same buy the watts will increase... adding the 2 wattage amounts together, also the amps....

I have 4 100 watt solar panels.... bought at different times, and they are slightly different sizes but the basic characteristics are the same... I have had no problems with the panels...

sincerely
Jess
 
Feb 14, 2014
12
Beneteau 331 North Fort Myers
Mismatched Solar Panels

Sorry, I can't absolutely answer your question, though I'm pretty sure it doesn't matter about the slight mismatch on the two panels, and your controller is 30 amp and the two panels put out maybe 11, so what's the worry there? But I did want to ask where on the 331 you mounted them!
Thanks for easing my worries (based on ignorance of solar mostly). I'm in the process of mounting them on the cabin top, hinged at the grab rails with the opposite side resting on the edge of the upper cabin structure, in between dorade and windscreen. They fit nicely, with each panel angled upward on opposite sides of the boat. 1 unit is 26.5'' x 40" and the other 26.5 x 44", long sides fastened to the grab bars with removable Sea Dog rail clamps. Still trying to figure out how to hold the upper portion firmly without penetrating fiberglass. Maybe industrial strength velcro or bungee cord or both?
 
Feb 14, 2014
12
Beneteau 331 North Fort Myers
hello all

attaching the 2 mismatched panels will not affect the out put or charging of your batteries... make sure you attach the cables in parallel not in series.... by hooking them up in series you will double the voltage.... in parallel the voltage will stay the same buy the watts will increase... adding the 2 wattage amounts together, also the amps....

I have 4 100 watt solar panels.... bought at different times, and they are slightly different sizes but the basic characteristics are the same... I have had no problems with the panels...

sincerely
Jess
Thanks. It gives me the confidence to do the installation. Your experience with solar is very reassuring. Two understandable and positive replies the same day - a great forum. Tom
 
Feb 14, 2014
12
Beneteau 331 North Fort Myers
Would love to see a picture if you get a chance, Tom!
Here are a couple pix taken at noontime tday.

Just finished the basic mounts & put panels in place for the next steps. Still have to resolve how to hold upper sections of the panels firmly without drilling into structure or putting undue loads on the corners of the cabin top, at the same time securing the panels from weather violence. If I wasn't worried about wind getting under the panels and raising havoc, just letting them lie as shown in the picture actually seems pretty secure with just the clamps tightened.
 

Attachments

Feb 6, 1998
11,436
Canadian Sailcraft 36T Casco Bay, ME
Here are a couple pix taken at noontime tday.

Just finished the basic mounts & put panels in place for the next steps. Still have to resolve how to hold upper sections of the panels firmly without drilling into structure or putting undue loads on the corners of the cabin top, at the same time securing the panels from weather violence. If I wasn't worried about wind getting under the panels and raising havoc, just letting them lie as shown in the picture actually seems pretty secure with just the clamps tightened.
The solar controller is the least of the worries in this installation. The location of the panels, & shading, will be the major detractor on solar performance.
 
Dec 7, 2012
515
Kittiwake 23, Irwin 43 .. Indianapolis / indianatown, fl
hello all

how about bolting a piece of trap steel or aluminum between the 2 solar panels.... I would also place a cushion material under the strap aluminum to cushion the panels on top of the cabin....this should keep them safe and secure on the cabin roof...

sincerely
Jess
 
Feb 14, 2014
12
Beneteau 331 North Fort Myers
hello all

how about bolting a piece of trap steel or aluminum between the 2 solar panels.... I would also place a cushion material under the strap aluminum to cushion the panels on top of the cabin....this should keep them safe and secure on the cabin roof...

sincerely
Jess
Last pix a work in progress. These were taken yesterday. Strap across top = 1.5" x .125" aluminum bar (local big box store) like straps under panels; fasteners = ss storm shutter bolts threaded through tangs on panels with wing nuts (1/4 - 20); cushioning mat'l = seat cushion foam (would like something a little firmer and neater looking, but will do for now). The big deal in the setup is the Sea Dog Removable Rail clamps which make it all possible. I got them through LFS Marine & Outdoor, excellent people. They come in pairs but the ads don't stress that, so don't double up like I did.
 

Attachments

Dec 7, 2012
515
Kittiwake 23, Irwin 43 .. Indianapolis / indianatown, fl
hello Tom

good looking setup you have there.... looks very efficient...

sincerely
Jess