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07-19-2014, 05:56 PM
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#1
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Senior Member
Join Date: Feb 2013
Location: Marana, Arizona
Trailer: 2018 Airstream Flying Cloud (Escape 19 & 5.0 previously)
Posts: 1,078
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Combining "new" 160W solar with "old" 95W?
Many of us have the 95W solar panel and (maybe) a little bit jealous of those who have the newer, more efficient 160W panel. I was wondering if it would be feasible (and how complex it may be [other than roof attachment]) to combine the new 160W panel with our existing 95W unit two into a "mega" 255W charger? Would it be necessary to make any changes to the controller or other electronics? Would it be a parallel or series connection? (Clearly, electrical mods are not my strong suit.)
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07-19-2014, 06:13 PM
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#2
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Senior Member
Join Date: Mar 2013
Location: Des Plaines, Illinois
Trailer: 2014 Escape 19 (TV: 2007 Chevy Tahoe)
Posts: 210
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Or, two 160's for those getting the new set-up?
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07-19-2014, 06:24 PM
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#3
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Senior Member
Join Date: Feb 2013
Location: Marana, Arizona
Trailer: 2018 Airstream Flying Cloud (Escape 19 & 5.0 previously)
Posts: 1,078
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Quote:
Originally Posted by pkgman51
Or, two 160's for those getting the new set-up?
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I think then it becomes a build sheet question since ETI would handle the combination. I'm interested in retrofitting.
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07-19-2014, 06:33 PM
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#4
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Commercial Member
Join Date: Apr 2014
Location: Hillsboro, Oregon
Trailer: 2014 Escape 21 - "Felicity"
Posts: 2,945
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I was at ETI last Friday and checked out the installation of the panels; they've epoxied the panel mounting rails onto the trailer surface. There are no holes drilled through the glass to screw things down, so a retro shouldn't be hard IF you have the roof area - the 160W panels are BIG; ETI mounts them behind and below the AC on the 21 to minimize turbulence that could produce an uplift effect.
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Charlie Y
Need custom storage to your design? Don't drill holes!
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07-19-2014, 07:15 PM
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#5
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Senior Member
Join Date: Dec 2012
Location: Edmonton, Alberta
Trailer: 1979 Boler B1700
Posts: 14,935
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Mounting issues aside, the electrical side can be easy: you can just parallel the two panels together. How optimally this works depends on the charge controller: the more basic the controller the less it matters that two panels are sharing one controller.
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07-19-2014, 07:59 PM
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#6
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Senior Member
Join Date: Sep 2009
Location: Southwick, Massachusetts
Trailer: None, sold my 2014 5.0TA
Posts: 7,124
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I don't see where the 160's are any more efficient then the 95's (17.8% vs 17.4%), just proportionally bigger. You need somewhere on the 19 that has space for a 26x58" panel. If you have MC4 connectors you can buy T's to combine the 2 panels on the roof. The only issue may be the size of the cable and the distance the total run will be. The 30A gopower solar controllers will handle both. If the run is fused you probably need to up it's value.
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Happy Motoring
Bob
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07-19-2014, 09:00 PM
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#7
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Senior Member
Join Date: Sep 2013
Location: Vancouver, BC, British Columbia
Trailer: 19'
Posts: 326
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I previously telephoned Go Power and asked if the 160 and 95 could be connected together. I was told no. If I remember correctly, because it was several months ago, they said the units are grounded differently and therefore cannot connect together.
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07-19-2014, 10:08 PM
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#8
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Senior Member
Join Date: Apr 2014
Location: Arvada, Colorado
Trailer: 2015 E'21 - 'Velocity'. Tow: Toyota Tacoma V6, 4X4, manual.
Posts: 1,698
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[QUOTE=...they said the units are grounded differently and therefore cannot connect together.[/QUOTE]
They might have given you the correct answer, but for the wrong reason.
For a solar panel, a ground is a ground. But if you try to hook them in parallel and one is a different voltage than the other, the higher voltage unit will try to discharge through the lower voltage unit - unless blocking diodes were used in the correct location. But the resulting combination would be very inefficient with the higher voltage unit providing the bulk of the power, and the lower voltage unit contributing almost nothing most of the time.
If they are the same voltage output then absolutely no problems with a parallel connection. Just connect a blocking diode to each panel and connect the ground to ground and the positive to positive, and consider the two panels as a single panel.
If you were trying to hook them in series the voltages combine because the ground of one panel connects to the positive of the other, just like two batteries in a flashlight. No blocking diodes needed. But the problem with series is that the combined voltage may exceed the limits of the controller in the worst case. And in a common scenario, the combined voltage would just be converted to wasted heat if the controller is a linear device (as opposed to a DC-DC converter). Should the controller be in fact a DC-DC converter and be able to function with 50 volts input, then this would be a very nice setup.
Obviously the correct answer depends on the specifics of each panel plus the controller, for which I have no first hand knowledge.
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07-19-2014, 11:46 PM
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#9
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Senior Member
Join Date: Dec 2012
Location: Edmonton, Alberta
Trailer: 1979 Boler B1700
Posts: 14,935
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I agree with alanmack's description of the electrical situation. I was assuming a parallel connection, because these panels are both clearly the same nominal voltage.
I am guessing - so corrections would be appreciated - that we're talking about
160 watt panel: CTI-160
95 watt panel: CTI-95
charge controller: GP-PWM-30
The operating voltage of the two panels looks pretty compatible to me for parallel connection. The controller appears to be unsuitable for series connection.
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07-20-2014, 12:36 PM
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#10
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Senior Member
Join Date: Feb 2010
Location: Oswego, New York
Trailer: 2017 Escape 21C, 2018 Ford F150
Posts: 5,385
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I believe the reason GoPower doesn't allow paralleling the 95 watt panel with the 160 watt panel is the metal frame of the 95 is connected to the positive side & the frame of the 160 connected to negative. If the frames are electrically connected together, that would cause a problem. Of course on a fiberglass trailer they wouldn't have to be, but code, at least for house sized systems, requires grounding the frames of the panels.
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07-20-2014, 01:00 PM
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#11
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Senior Member
Join Date: Feb 2010
Location: Oswego, New York
Trailer: 2017 Escape 21C, 2018 Ford F150
Posts: 5,385
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I've also discovered an interesting problem with my folding 160 watt panel when combined with the 95 watt roof top panel.
When the roof panel is in the shade & I set up the folding panel in the sun (one of the reasons I purchased it), the folding panel controller never goes into the boost mode, instead it only charges at the float levels.
It is annoying to see a panel that is capable of putting out 8.5 amps only producing an amp or two in full sun. While I don't have an easy way to prove it since it is difficult to disconnect the built in panel, I suspect the problem is the two controllers fighting each other, with the roof top panel putting out enough voltage to convince the portable controller that the batteries are full.
My solution, when I get back to NY, will be to bypass the folding panel's controller & combine the panels feeding either the GoPower's controller or purchase a different controller that is better matched to the Interstate battery charging requirements.
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07-20-2014, 01:12 PM
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#12
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Senior Member
Join Date: Sep 2010
Location: Kelowna, British Columbia
Trailer: 2008 Escape 17b
Posts: 1,868
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Is that when you hook your folding panel directly to the battery or when you 7 pin into the pig tail?
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07-20-2014, 01:28 PM
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#13
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Senior Member
Join Date: Feb 2010
Location: Oswego, New York
Trailer: 2017 Escape 21C, 2018 Ford F150
Posts: 5,385
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It is through the 7 pin connector - I use that because I have a battery monitor that I use to determine the output. When I have a heavy load on the system & both panels in the sun, the portable panel does put out 8.5 amps.
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07-20-2014, 02:42 PM
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#14
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Senior Member
Join Date: Sep 2010
Location: Kelowna, British Columbia
Trailer: 2008 Escape 17b
Posts: 1,868
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When the time comes that you by-pass the folding panel's controller and choose to use the GoPanels controller will you be using MC4 connectors or the 7 pin?
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07-20-2014, 04:49 PM
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#15
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Senior Member
Join Date: Dec 2012
Location: Edmonton, Alberta
Trailer: 1979 Boler B1700
Posts: 14,935
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Quote:
Originally Posted by Vermilye
I believe the reason GoPower doesn't allow paralleling the 95 watt panel with the 160 watt panel is the metal frame of the 95 is connected to the positive side & the frame of the 160 connected to negative. If the frames are electrically connected together, that would cause a problem. Of course on a fiberglass trailer they wouldn't have to be...
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That's bizarre, but maybe not a problem for paralleling - Escapes with the 95 watt panel obviously don't have the panel frame connected to the trailer frame, and apparently the panel frame is live compared to the trailer ground... good thing it's only 12 volts! The key is apparently to not connect either panel frame to the trailer frame.
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07-20-2014, 06:21 PM
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#16
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Senior Member
Join Date: Feb 2010
Location: Oswego, New York
Trailer: 2017 Escape 21C, 2018 Ford F150
Posts: 5,385
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Quote:
Originally Posted by J Mac
When the time comes that you by-pass the folding panel's controller and choose to use the GoPanels controller will you be using MC4 connectors or the 7 pin?
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The choice of connectors is still out, but it won't be the 7 pin since I'll want to feed the input of the controller.
I'd like a waterproof chassis mount connector since it won't be in use when I'm just using the built in panel. I've used & like the Neutrik SpeakerON connector and it is sealed, but no cover. The problem with most chassis mount connectors are they are outlets, not inlets, which I would prefer with a solar panel. I'm still looking...
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07-20-2014, 09:11 PM
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#17
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Senior Member
Join Date: Jul 2010
Location: Rockwell, North Carolina
Trailer: 2015 Escape 5TA
Posts: 170
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If you are referring to cable connection, the item you could use is a flanged inlet. It looks like the male end of a drop cord, but it is recessed into a housing. I use them on my solar controller to connect the array to it. A standard drop cord between the array and controller is simple. The wiring at the controller either parallels or series the panels as necessary. I use a morning star mppt controller which takes up to 75V open circuit.
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02-07-2015, 01:39 PM
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#18
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Senior Member
Join Date: Oct 2014
Location: Chattanooga, Tennessee
Trailer: 2015 19 foot
Posts: 439
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Jon, Have you been able to test bypassing the folding panel's controller?
PS: I really enjoy reading your trip reports.
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02-07-2015, 02:42 PM
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#19
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Senior Member
Join Date: Sep 2009
Location: Southwick, Massachusetts
Trailer: None, sold my 2014 5.0TA
Posts: 7,124
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Quote:
Originally Posted by Vermilye
I'd like a waterproof chassis mount connector since it won't be in use when I'm just using the built in panel. I've used & like the Neutrik SpeakerON connector and it is sealed, but no cover. The problem with most chassis mount connectors are they are outlets, not inlets, which I would prefer with a solar panel. I'm still looking...
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Jon, If you have yet to find a connector, how about one of these? They have them on Amazon as well but the image is not as good.
Marinco 150BBIW.RV White 15 Amp Power Inlet
Must be what Strawberry mentions.
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Happy Motoring
Bob
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02-07-2015, 03:05 PM
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#20
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Senior Member
Join Date: Jun 2010
Location: Central, Pennsylvania
Trailer: Escape#5 2022 E19
Posts: 26,268
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So, what is the solution to adding a second panel and having them work together vs against one another?
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Jim
Sometime life gets in the way of living.......
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