Additional Solar Capacity

elbolillo · December 11

I just finished installing another 180w solar panel on our '23 Tab 400. 360w total now on the roof. Removed the smaller 75/10 MPPT and installed a 100/30 MPPT to handle the two 180w panels wired in parallel. Nice to have the controller out from back behind the fridge to a more easily accessible spot. I just need to tidy up and secure the cabling on the roof and we are ready for boondocking adventures.

dsfdogs · December 11

@elbolillo Nice work! Can you show a broader picture of where you installed the second panel?
Thank you!

elbolillo · December 11

@dsfdogs

Here is a photo of the panel installed on the front. I still need to secure the cabling.

Image: https://us.v-cdn.net/5021717/uploads/editor/g4/971rlk9bh98d.jpeg

pthomas745 · December 11

And: can you explain how you wired "through the roof?" I think this is always the hardest issue for owners who want to do something like this.

boathealer · December 11

pthomas745 said:

And: can you explain how you wired "through the roof?" I think this is always the hardest issue for owners who want to do something like this.

Another option - I didn't want *ANY* (more) holes in my roof. I ran the cables from my two 200W panels up under the trim piece and down forward to the bottom. It is hollow all the way down. There is an opening at the end and the cables can be run into the underbelly and up through the floor.

Image: https://us.v-cdn.net/5021717/uploads/editor/4y/3vnagktq568o.jpg

Image: https://us.v-cdn.net/5021717/uploads/editor/gr/9anguhbxppgi.jpg

elbolillo · December 11

pthomas745 said:

And: can you explain how you wired "through the roof?" I think this is always the hardest issue for owners who want to do something like this.

I just used the existing penetration and ran the cables to the branch connectors that will be secured to the roof.

AnOldUR · December 11

@elbolillo What brand flexible panel is that?

I want to compare it to the 200W BougeRV that @boathealer used.

elbolillo · December 11

@AnOldUR

It is the same panel that came with the '23 Tab 400: Sunflare Flex 180. I went with this panel because I wanted to match the panels and parallel them on the same MPPT charger.

elbolillo · December 11

Here are a couple of additional photos for reference. I could have run all the wires to the inside of the Tab and then attached them to the branch connectors. However, I decided on this route. I have adhesive mounting brackets to secure all the wires and branch connectors.

RTWCTS · December 11

@AnOldUR here are the specs for the Sunflare panel

Image: https://us.v-cdn.net/5021717/uploads/editor/49/9oonv7pg4oa1.png

Here is the website
Flex+ / Flex — XPLOR by Sunflare

AnOldUR · December 11

@RTWCTS Any idea why efficiency and other specs are so much different than the BougeRV (below) for a comparable wattage panel? The Sunflare has a larger footprint, but slightly lower wattage. Also the price difference? Are the Sunflare that much better?

Image: https://us.v-cdn.net/5021717/uploads/editor/73/pke1bukbp6uh.jpg

boathealer · December 11

Image: https://us.v-cdn.net/5021717/uploads/editor/fc/d0ypuik4jkz7.jpg

CatDaddy · December 11

elbolillo said:

Removed the smaller 75/10 MPPT and installed a 100/30 MPPT to handle the two 180w panels wired in parallel.

Wiring two panels in parallel isn't a good idea. It won't necessarily hurt anything, but it will impact performance very significantly, especially if one panel is shaded and the other is not.

A better approach is to use two separate MPPTs. I've been looking for a dual input MPPT for exactly this purpose, but I'm not finding one. The best thing I've found is two MPPTs that will "network" so they can cooperate to charge the battery(ies).

elbolillo · December 12

CatDaddy said:

elbolillo said:

Removed the smaller 75/10 MPPT and installed a 100/30 MPPT to handle the two 180w panels wired in parallel.
Wiring two panels in parallel isn't a good idea. It won't necessarily hurt anything, but it will impact performance very significantly, especially if one panel is shaded and the other is not.
A better approach is to use two separate MPPTs. I've been looking for a dual input MPPT for exactly this purpose, but I'm not finding one. The best thing I've found is two MPPTs that will "network" so they can cooperate to charge the battery(ies).

Actually, when wired in series, shading effect the performance.

Quote from Battleborn's site: "Solar panels in parallel operate independently of one another and therefore are the best option for mixed-light conditions. If shade covers one or two of your panels, the remaining panels in the array will continue to generate power as expected."

elbolillo · December 12

boathealer said:

I am not sure where you pulled the spec for the Sunflare Xplor but this is directly from their site:

elbolillo · December 12

RTWCTS said:

@AnOldUR here are the specs for the Sunflare panel

Here is the website
Flex+ / Flex — XPLOR by Sunflare

Not sure where you pulled the screen shot, but Sunflare's website give much different specs.

elbolillo · December 12

AnOldUR said:

@RTWCTS Any idea why efficiency and other specs are so much different than the BougeRV (below) for a comparable wattage panel? The Sunflare has a larger footprint, but slightly lower wattage. Also the price difference? Are the Sunflare that much better?

I could be wrong, but these BougeRV panels do not appear to have bypass diodes to allow the panel to function fully in shade. Their YUMA models do.

The Sunflare panels do have bypass diodes.

RTWCTS · December 12

AnOldUR said:

@RTWCTS Any idea why efficiency and other specs are so much different than the BougeRV (below) for a comparable wattage panel? The Sunflare has a larger footprint, but slightly lower wattage. Also the price difference? Are the Sunflare that much better?

I am not that familiar with the BougeRV product @AnOldUR. I would imagine it has to do with how the individual cells are connected in producing the panels.
When I started reading this discussion, I looked up the specs for the Sunflare panels online (since I have one on the roof of my T@B). For my auxiliary solar needs, I use briefcase panels connected to a second Victron MPPT controller.

RTWCTS · December 12

elbolillo said:

RTWCTS said:

@AnOldUR here are the specs for the Sunflare panel

Here is the website
Flex+ / Flex — XPLOR by Sunflare

Not sure where you pulled the screen shot, but Sunflare's website give much different specs.

@elbolillo I went to Sunflare's website after reading your initial post (the link is posted in my first comment in this discussion). Under the resources tab you can open the "Download The Understanding Solar Guide".

Image: https://us.v-cdn.net/5021717/uploads/editor/hq/9kj6pi9cs8tl.png

The data table I posted is from that guide. So, it is from Sunflare.

AnOldUR · December 12

@RTWCTS I found this on their website:

Why is it more expensive than other modules per watt?

Our technology is inherently different from our competitors, and while it is more expensive, our quality and performance make up for the price differences. Bypass diodes make up for increased performance under shaded conditions, and our 3M top sheet is best in class for all-weather protection year-round.

I'd like to see the Understanding Solar Guide, but get, "Unable to submit your request. Please contact the website administrator." I've emailed them to find out why. Do you know of any trick to get in?

RTWCTS · December 12

The .PDF is attached below @AnOldUR . I had downloaded it yesterday...

elbolillo · December 12

Seems like Sunflare is not totally consistent with their specs. Here is the spec sheet for the 180w panel.

CatDaddy · December 12

elbolillo said:

Actually, when wired in series, shading effect the performance.

Quote from Battleborn's site: "Solar panels in parallel operate independently of one another and therefore are the best option for mixed-light conditions. If shade covers one or two of your panels, the remaining panels in the array will continue to generate power as expected."

Full disclosure: I'm an electrical engineer that has designed MPPT systems professionally. I'm telling you the truth. Both series and parallel configurations have issues with shading, but wiring them in parallel more fraught with issues. There is a reason why commerical PV solar installations are almost 100% series strings.

What Battleborn wrote is correct, but your interpretation of it is incomplete. Battleborn did not say that wiring panels in parallel provides the maximum power output. Panels in parallel that are properly configured with blocking diodes don't really "cooperate" that well, meaning that the panel with the highest output voltage will provide almost all of the power and the others aren't doing anything. This is particularly true if they panels are not identical.

If the goal is to get the maximum power available from all of the panels, then the optimal solution is to have one MPPT per solar panel (aka "module").

If one could find the right hardware, then putting them in series with a good MPPT is the second best in terms of maximizing power output.

Putting them in parallel requires proper blocking diodes and heavier wire to handle the higher current is third best.

I have not been able to find any information about how NuCamp wires their systems for having an external portable panel, but from what I can tell, they provide a second MPPT that connects directly to the battery.

This is my professional advice. You're free to take it or leave it, but I'm not willing to get into a debate about the objective facts.

Marceline · December 12

CatDaddy said:
I have not been able to find any information about how NuCamp wires their systems for having an external portable panel, but from what I can tell, they provide a second MPPT that connects directly to the battery.

AFAIK Pleasant Valley (NuCamp) has only installed controllers in units with solar on the roof. For a while they were installing an SAE port on the sidewall of the front tub, and this SAE port was wired straight to the battery. It was meant for use with a Zamp brand suitcase setup that included its own controller (there was even a "Zamp" sticker next to the port), but of course people have plugged other solar suitcases into it.

rfuss928 · December 12

elbolillo said:

I just finished installing another 180w solar panel on our '23 Tab 400. 360w total now on the roof. Removed the smaller 75/10 MPPT and installed a 100/30 MPPT to handle the two 180w panels wired in parallel. Nice to have the controller out from back behind the fridge to a more easily accessible spot. I just need to tidy up and secure the cabling on the roof and we are ready for boondocking adventures.

What is the second MPPT 100/30 for?

CatDaddy · December 13

Marceline said:

AFAIK Pleasant Valley (NuCamp) has only installed controllers in units with solar on the roof. For a while they were installing an SAE port on the sidewall of the front tub, and this SAE port was wired straight to the battery. It was meant for use with a Zamp brand suitcase setup that included its own controller (there was even a "Zamp" sticker next to the port), but of course people have plugged other solar suitcases into it.

That's super helpful, thanks! This supports my thesis that wiring panels in parallel is not optimal.

I saw a few T&Bs with the solar port on the side of the tub in photos, but I didn't know if there was a controller mounted inside the tub or if they expected the external panel to have it's own controller. Sounds like it was the latter!

elbolillo · December 13

rfuss928 said:

elbolillo said:

I just finished installing another 180w solar panel on our '23 Tab 400. 360w total now on the roof. Removed the smaller 75/10 MPPT and installed a 100/30 MPPT to handle the two 180w panels wired in parallel. Nice to have the controller out from back behind the fridge to a more easily accessible spot. I just need to tidy up and secure the cabling on the roof and we are ready for boondocking adventures.

What is the second MPPT 100/30 for?

The second MPPT is for my external panel.

pthomas745 · December 13

@CatDaddy some owners mounted controllers inside the trailer (tub, etc) connected it to the wiring of the SAE port, and then ran the cables from the controller to the battery. The cables from the solar panel connected to the port. Others had the solar controller completely separate from the trailer. That could either be from a "suitcase" panel with the controller mounted on the panel. The other way is to have a separate controller much closer to the trailer with a short cable to the SAE port. It was always considered more efficient to have the solar controller close to the battery.

elbolillo · December 13

CatDaddy said:

elbolillo said:

Actually, when wired in series, shading effect the performance.

Quote from Battleborn's site: "Solar panels in parallel operate independently of one another and therefore are the best option for mixed-light conditions. If shade covers one or two of your panels, the remaining panels in the array will continue to generate power as expected."

Full disclosure: I'm an electrical engineer that has designed MPPT systems professionally. I'm telling you the truth. Both series and parallel configurations have issues with shading, but wiring them in parallel more fraught with issues. There is a reason why commerical PV solar installations are almost 100% series strings.
What Battleborn wrote is correct, but your interpretation of it is incomplete. Battleborn did not say that wiring panels in parallel provides the maximum power output. Panels in parallel that are properly configured with blocking diodes don't really "cooperate" that well, meaning that the panel with the highest output voltage will provide almost all of the power and the others aren't doing anything. This is particularly true if they panels are not identical.
If the goal is to get the maximum power available from all of the panels, then the optimal solution is to have one MPPT per solar panel (aka "module").
If one could find the right hardware, then putting them in series with a good MPPT is the second best in terms of maximizing power output.
Putting them in parallel requires proper blocking diodes and heavier wire to handle the higher current is third best.
I have not been able to find any information about how NuCamp wires their systems for having an external portable panel, but from what I can tell, they provide a second MPPT that connects directly to the battery.
This is my professional advice. You're free to take it or leave it, but I'm not willing to get into a debate about the objective facts.

I won’t debate the objective facts either. FACT: Shading definitely affects panels wired in series more than if wired in parallel. https://www.youtube.com/watch?v=ofo1HQyGG8s&t=43s

I never said that wiring in parallel would provide maximum output. And let’s not confuse an RV installation on a small camper with a commercial installation of solar panels. My 8kwh solar panel installation on my house is a totally different beast compared to a camper that is meant to travel and inhabit many different types of situations.

With many things what may be optimal isn’t necessarily black and white. Just because your way would provide maximum output, it doesn’t by any stretch of the imagination mean it is the only correct option.

I already have two MPPT controllers in a small trailer and really didn’t want to install another. Series wiring runs are definitely more efficient, however, although I have wired in parallel, my runs are fairly short and loss should be minimal. And my panels are identical.

I certainly am not adverse to different ideas and opinions, but most things require some semblance of compromise dependant on the particular use scenarios. If you really wanted a camper that provided optimal output, you wouldn’t be using 12v. However, running 24v or 48v would require a totally different setup.

CatDaddy · December 13

I won’t debate the objective facts either. FACT: Shading definitely affects panels wired in series more than if wired in parallel. https://www.youtube.com/watch?v=ofo1HQyGG8s&t=43s

I can provide SPICE simulations that refute your "facts" if you're interested. Otherwise, you do you.

elbolillo · December 13

CatDaddy said:

I won’t debate the objective facts either. FACT: Shading definitely affects panels wired in series more than if wired in parallel. https://www.youtube.com/watch?v=ofo1HQyGG8s&t=43s

I can provide SPICE simulations that refute your "facts" if you're interested. Otherwise, you do you.

The real world is great for me, thanks.

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