Upgrading the 100W Solar Panel on a 2020 320S (new post)

AnOldUR

My old Jeep was not much help charging my trailer batteries. I considered a DC-DC charger, but beside the added load on the alternator, I was also concerned about the different charging profiles between the LiFePO4's in the trailer and the lead acid in the Wrangler. For that last reason, I disconnected the trailer charge wire at the T@B's junction box. There wasn't a problem with the existing 100W rooftop solar charging the trailer batteries while on the road, but I was looking for a little more.

After over a year of researching and help from members of this forum I went with the 310W Sunflare solar panel that comes on some of the 400 T@B's. I purchased it through our local nuCamp dealer, Miller in Pennsylvania, and it was drop shipped to my house. The cost was $765 before shipping and tax. I also had to upgrade the Victron solar controller from the 75/10 to a 100/30. That was an additional $118.

The hardest part of this project was removing the old panel and the remains of the two sided tape. If you decide to go ahead with it, allow a full day for this part of the job. I spread it out over a few days because it was so frustrating. The other challenge is that the junction box on the new panel is in a different location, so it required a new hole through the skin of the roof. Nothing broke out inside the trailer. Luckily there was enough existing wire to reach the new box.

I'm very happy with the results. It's a clean look with no wires visible. Although the sun is still low in the sky this time of year, I got a chance to test it today. The P max was 229W. The factory 10awg wire between the controller and batteries is safe amperage wise, but there's enough voltage drop that I'll swap that out if/when I get the motivation. I may even move the controller closer to the battery from the factory location under drivers side the bench seat. For now, the extra charge while on the road will help and it will be a great compliment to our solar suitcase once we reach a destination.

Sharon_is_SAM

Nice job!

elbolillo

Great job! I am sure this setup will provide the extra oomph you are looking for. I ran 8 awg between my solar controllers and batteries. The runs are only about 4-6’ give or take.

I had excellent solar charging from MN to Texas, Texas to Arizona and on to Cali and then all the way home.

B0atguy

Looks good @AnOldUR ! Pretty much looks like a Nucamp factory install . Good numbers too . I think the max output I have seen from our 310 panel was 250w . I dont really position the T@B in a perfect position for panel coverage , so I am sure it could do better . 
I would totally add another 310 panel to our 400 , but its the interior wiring that has me nervous . I am not pulling down any part of the interior headliner / ceiling,  to gain access to run the "new" solar panel wiring. Thats an aluminum tubular structure un there , and I cant see any easy way to run the wiring . 
In hindsight , I should have opted for the "black canyon" package . 

AnOldUR

Thanks @B0atguy & @elbolillo! The concerns about wiring are the same as mine with upgrading the wires for the larger panel. Sure would be nice if nuCamp would prewired for the Black Canyon package to make an upgrade more practical in your case, or run heavier wire between the controller and battery in my case. It doesn't seem like the cost to them would be that significant and it would be a good selling point. For your situation, running the wires inside the cabin with wire cover to conceal them might be the way to go. You'd need a big hole on the outside roof for the junction box, but only a small one through the headliner.

In the case of the 310W panel, it's fortunate that it's higher voltage/lower amperage, so voltage drop between the panel and controller through 10awg wire is less of an issue than it is going to the battery.