Rooftop Solar Replacement

AnOldUR

Our 2020 320S came with a 100W flexible panel on the front part of the roof. The panel still works, but I've read that flexible panels lose efficiency over time. I'm tossing around the idea of putting a larger (200W?) panel in that location for more charging while on the road (we have a 200W suitcase for supplemental charging while camping). I have a couple of feelers out to find out if this is practical, but wondered if anyone here may have had this done and the cost involved.

I know that I'll have to replace the 75/10 controller, but I'm hoping that the existing wiring would be enough to support the additional current. Swapping the controller is something I can do, but taking off the old panel and replacing it is something I'm not comfortable with.

kevmon

Where is (are) your battery (batteries)?

AnOldUR

@kevmon Two 100Ah LiFePO4's in a truck box on the tongue.

kevmon

Replacing the Victon with something that can handle 200 watts of solar panels would be a drop-in replacement for what you already have (for example, the Victron 75-15 is about $70).

The panels are trickier and more expensive. @Verna has a nice setup (https://tab-rv.vanillacommunity.com/discussion/12664/adding-a-second-solar-panel). I believe you could add a 200-watt panel to what you already have, but that would require a charger larger than a 75-15.

pthomas745

In this thread, an owner simply installed the new panels right over the old (failed) panels. 

https://tab-rv.vanillacommunity.com/discussion/13878/2019-tab400-factory-solar-panels-dead

Other threads showing removal of the old panels (depending on the adhesive method used) are not very pretty, but there are good threads showing how.

https://tab-rv.vanillacommunity.com/discussion/7621/removing-flexible-solar-panels-mounted-with-vhb-tape

https://tab-rv.vanillacommunity.com/discussion/11493/flexible-solar-panel-removal

RTWCTS

We added 200W of solar to our old 320. The panels were placed behind the rooftop vent, on the back. I routed the wiring under the trim and to the front tub where the battery was (similar to your setup) and installed the Victron in the tub. 
If your current system still works, there is nothing wrong with using more than one controller. In fact, it is best way to optimize panels with different specs. We do that with our 400 now.

AnOldUR

Interesting replies. I've heard back from nuCamp and they seem reluctant to remove the old panel because of fear of damaging the roof in the process. They are suggesting, like @RTWCTS did, adding panels behind the roof vent. Between having a rack on the back that limits space and my original panel being four years old, I'd rather go the replacement route. From the threads linked to above, it looks like removing the panel is possible, just difficult. The idea of putting a new panel over the old is a possibility.

What I haven't been able to find is where the wires from the original panel go into the roof. I'll have to look closer, but if anyone knows where on the panel that connection is, it would be helpful.

rfuss928

I also added more panel area to the rear roof on our UT -CSS.  162 watt Sunflare panel installed at NuCamp Service Center fit nicely in the space available.   267 watts total solar with the 105 watt on the front.  A second Victron controller was added for the rear panel.  With 2 X 100 AH LiFePO we're good for 3-4 days with little or no solar and can easily recover in one decent sunny day.

AnOldUR

@rfuss928 Would you share what nuCamp charged for that upgrade?

rfuss928

The Sunflare panel was ~$600.  Three hours shop time plus materials was about the same.  I installed the second controller before taking it in.  We're very happy with the quality of the work.
The Sunflare panels are very high quality, roof service rated panels.  That had a lot of value to me.  My UniSolar panels on SUNT@B had a similar rating and were still performing as new after 12 years and 80k miles.  

XenanMe

I had to remove a failed flexible panel on my 400 a few years back. It wasn’t pleasant. I strongly recommend installing the new panel over the old one if possible. Then put Eternabond tape around the edges to seal everything down tight. You shouldn’t need to upgrade the wiring.  Good luck.

AnOldUR

I'd rather not, but installing a new panel over the old one is looking more inviting. On first look, I can't find where the wiring goes into the roof. Any hint on how to identify this location.