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JandL
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Joined: 29 Mar 2014
Location: California
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Posts: 364
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Topic: 200 W solar mod Posted: 28 May 2016 at 10:13pm |
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JandL
2013 Honda Ridgeline
2012 177
2 Paynes in a Pod
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john in idaho
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Joined: 04 Nov 2014
Location: Eagle Idaho
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Posts: 611
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Posted: 29 May 2016 at 9:03am |
Just thinking about solar panels. From the photos, it looks like you are in some shade. Will the panels still work in dappled shade like that?
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sailor323
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Joined: 11 Jun 2015
Location: S Central KY
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Posted: 29 May 2016 at 9:07am |
Very nice installation.
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sailor323
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Location: S Central KY
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Posted: 29 May 2016 at 9:09am |
Originally posted by john in idaho
Just thinking about solar panels. From the photos, it looks like you are in some shade. Will the panels still work in dappled shade like that? |
Even a small amount of shade, dirt and debris on the panels, will have a significant negative effect on the amperage. The panels might produce enough power to keep fully charged batteries topped up but they won't produce enough to recharge batteries.
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JandL
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Joined: 29 Mar 2014
Location: California
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Posted: 29 May 2016 at 9:15am |
Will the panels still work in dappled shade like that?
They do not do very well in the shade. I set the panels up late in the afternoon after arriving. If I had left them on the ground I could have moved them into to sun. I wanted to get pictures to post of them mounted on the trailer. Later that night it rained and was overcast the whole weekend, I was surprised the panel put 1/2 - 1 amp with the cloud cover. If they were in full sun it would be more like 8 -9 amps
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JandL
2013 Honda Ridgeline
2012 177
2 Paynes in a Pod
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sailor323
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Joined: 11 Jun 2015
Location: S Central KY
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Posted: 29 May 2016 at 3:31pm |
Check this out for the effect of shade on solar panel output. Remember, that voltage is not the consideration when charging the batteries, amperage is determining factor. https://www.youtube.com/watch?v=QzzB1i1w_kM http://www.solarchoice.net.au/blog/partial-shading-is-bad-for-solar-panels-power-systems/ While shade can drastically reduce a panel's output, some panels work better in shade than others. Better (more expensive) panels are wired with bypass diodes so when part of the panel is not producing power, the power produced by the rest of the panel is delivered to the controller. When this is the case, the panel's production is greatly reduced, but not completely lost. Panels equipped with bypass diodes can work in partially shady conditions but we are talking about shade that covers a very small part of the panel and even then, it depends on which part of the panel is shaded. If only a tiny portion of each string of cells is covered, the bypass diodes are of no use. By the way, the folks at altE are very helpful and their prices are very good
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JandL
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Joined: 29 Mar 2014
Location: California
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Posts: 364
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Posted: 29 May 2016 at 3:54pm |
When the picture was taken, with the shade on the panels, I was getting no output. The next day when it would stop raining and the cloud cover was not as thick, enough light was getting thru the clouds to charge the battery's at around 13.6-13.8 volts and when I checked with my amp meter I got between .5 to 1 amp. The voltage from the panel has to be high enough to force current back into the battery so voltage has to be taken into account.
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JandL
2013 Honda Ridgeline
2012 177
2 Paynes in a Pod
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WillThrill
Senior Member
Joined: 04 Jul 2014
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Posts: 298
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Posted: 29 May 2016 at 4:31pm |
Originally posted by sailor323
Originally posted by john in idaho
Just thinking about solar panels. From the photos, it looks like you are in some shade. Will the panels still work in dappled shade like that? |
Even a small amount of shade, dirt and debris on the panels, will have a significant negative effect on the amperage. The panels might produce enough power to keep fully charged batteries topped up but they won't produce enough to recharge batteries.
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That's why I'm not a big fan of mounted solar panels on an RV, at least for us. We typically use our Pod in the summer, and we have a big preference for shaded campsites, but this does not work well at all with solar panels. I put my single 100 watt Renogy panel on a 15 ft. cord so I can move it around to the brightest spot.
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"Not all those who wander are lost." Tolkien
2014 Hood River 177
2005 GMC Envoy XL
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JandL
Senior Member
Joined: 29 Mar 2014
Location: California
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Posts: 364
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Posted: 29 May 2016 at 4:54pm |
"That's why I'm not a big fan of mounted solar panels on an RV, at least for us."
I installed my panels with clamps so when need I can remove them and place them on the ground and point them toward the sun. The cable is about 12' long so I can move it to any side. The big advantage of clamping them to the roof is I hope they are a little harder to keep from walking away
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JandL
2013 Honda Ridgeline
2012 177
2 Paynes in a Pod
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sailor323
Senior Member
Joined: 11 Jun 2015
Location: S Central KY
Online Status: Offline
Posts: 281
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Posted: 29 May 2016 at 6:52pm |
Originally posted by JandL
When the picture was taken, with the shade on the panels, I was getting no output. The next day when it would stop raining and the cloud cover was not as thick, enough light was getting thru the clouds to charge the battery's at around 13.6-18.8 volts and when I checked with my amp meter I got between .5 to 1 amp. The voltage from the panel has to be high enough to force current back into the battery so voltage has to be taken into account. |
True enough, but remember, volts X amps = watts. 1/2 amp at 18.8 volts is 9.4 watts, a tiny fraction of the output that a 100 watt panel should produce. The controller is what adjusts the current and voltage delivered to the battery. A one amp current is probably enough to keep fully charged batteries topped up.
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