Finished solar install

[Shocksll]

Finally finished the solar install on our 2021 Casita Heritage Deluxe.

4 x Renogy 100w panels
Victron SmartSolar 100/30 MPPT controller
2 x Battleborn 100Ah heated batteries
PD 4655L Wildkat converter
Victron Orion Tr Smart 12|12|18A DC-DC charger
Victron BMV-712 battery monitor

Because of the massive space under the bunks of our Heritage Deluxe, I was able to create some mounts for both batteries under the bunk beds.

I didn’t want to put any holes in the roof so I used VHB tape on the panel legs and went through the grey vent for the wire run.

Excited to see how much this will extend our boondocking capabilities.

[jwcolby123]

I'm thinking of mounting mine the same way, angled down the curve of the roof of my Scamp 19. If boon docking where you can park to face the sun it would work quite well.

Can you comment on how much sun you get per panel pair? Do you put them all in parallel? Each side in series?

I saw one guy that mounted each panel high enough to place another on slides under the top panel. If I could find some server rack slides that have a hinge in the middle for angling the bottom panel this would make a great mount as well.

Anyway, job well done!

[Shocksll]

Thanks! I decided to wire them all in parallel so if any of them are shaded it didn’t affect the others. I just finished it this morning but the side facing the sun in the morning generated 400w in 3 hours. By the time my battery was charged around 1 or so the whole system had generated 700w.

[Perryb67]

Nice install! I especially like your out-of-the-box mounting! You should be able to fill those Battleborns easily.

Enjoy,

Perry

[Shocksll]

Thanks!

[Bob Penn]

Originally Posted by Shocksll

Finally finished the solar install on our 2021 Casita Heritage Deluxe.

Excited to see how much this will extend our boondocking capabilities.

Very nice install! Did you receive technical support for the design and selection of components for your install?

In the blogs I have read with multiple solar panels, they seemed to always have all of the panels in series. I am not aware of the advantages/disadvantages of either a series or parallel hookup. In your case, it would seem that panels on the same side would be in series and in parallel with the panels on the opposite side of the trailer.

Based on the first time use of your system, it appears that you did everything right. I note that you did not skimp on quality. You should have long and reliable service as a result. Enjoy your boondocking.

[Perryb67]

Originally Posted by Bob Penn

In the blogs I have read with multiple solar panels, they seemed to always have all of the panels in series. I am not aware of the advantages/disadvantages of either a series or parallel hookup. In your case, it would seem that panels on the same side would be in series and in parallel with the panels on the opposite side of the trailer.

If you camp underneath trees we have found the rear panels can be in shade and the front in sun. In that situation parallel is better. If you rarely have this happen then series is better. We just added three 100 watt Renogy panels to the existing 170 watt panel and chose parallel for two reasons:

• we camp in shady spots quite often
  
  
• with mismatched panels we get 465 watts wiring in parallel, but only 405 watts in series.

Mismatched wattage panels is another reason for parallel.

Enjoy,

Perry

[Bob Penn]

Perry, thank you! You answered a few important questions for me. My solar system at this point is a 230 watt Zamp solar suitcase system plugged into a solar plug on the side of my Casita. I am considering additional panels. What is confusing for me, is that I see most solar panels rated in watts not amps. Yet the solar controller for my Zamp is rated at 15 amps. If I decided to add any additional panels, I will either need to change my solar controller to allow for the additional "amps" or find out if multiple controllers can work together. I am ass-u-ming that the latter is not possible. A myriad of questions then run through my mind as to what is needed to accommodate the extra panels. Based on what you stated, I should hook everything up in parallel. I don't know if my Zamp suitcase system is in parallel or series.

[Shocksll]

So, when running the panels in series, the voltage is additive and the amperage remains the same. When running parallel, the amperage is additive and the voltage remains the same.

The panels I see have both a Voltage Open Circuit (Voc) measured in volts and Short-Circuit Current (Isc) measured in amps. Both of these are based on how much sun it's get of course.

So all 4 of my panels are 22.3V (Voc) and 5.86A (Isc).

So I had three wiring options:

1. Put them all in series, then my max voltage would be 89.2 volts and my max current would 5.86A.
2. Put them all in parallel, then my max voltage would be 22.3 and my max current would be 23.44A.
3. Put each side in series and then both sides in parallel, then my max voltage would be 44.6V and max current would be 11.72.

My MPPT controller supports a maximum of 100V and 30A. So any of these options would work with my solar controller.

As mentioned by Perry, when using series, if any of the panels are shaded, then it brings down the output of the other panel(s) that could be in full sun. Because I wanted to mount mine on opposite sides of my trailer, I was figuring that most cases there would be at least one panel that is at least partially shaded. So option 1 was a no go for me.

Since I was running 10 awg wire for a long distance, I am concerned about the voltage drop that happens when pushing a lot of current over a long distance over a smaller wire size. Given this Option 3 seemed like a great option but I was concerned about my large A/C unit partially shading the rear panels.

Option 2 was the one I ended up going for but I am probably seeing about 1.5V of drop happen over the long 10awg wire runs. With how I have it wired, I could easily switch to option 3 at some point. Right now I wanted to get a baseline and see how it performs and then I can tweak if needed for potential better performance. Option 2 required the most amount of wires run so I went with it first and I can always remove wires later if I decide Option 3 works better.

I hope this makes sense and helps you out.

[Deb & Chuck]

So how much weight did you add to your 3,500 pound axle?

[Shocksll]

Originally Posted by Deb & Chuck

So how much weight did you add to your 3,500 pound axle?

The panels are 14 lbs each, so 56 lbs for those. The wiring was probably another few pounds. My existing Group 27 battery was 50 lbs and the total of both of my new batteries are 62 lbs. So an extra 12 lbs there. The feet are pretty light, maybe a pound each, so another 16 lbs. 4-6 lbs for the MPPT controller and DC-DC charger.

So I would say less than 100 lbs.

[Bob Penn]

Originally Posted by Shocksll

The panels are 14 lbs each, so 56 lbs for those. The wiring was probably another few pounds. My existing Group 27 battery was 50 lbs and the total of both of my new batteries are 62 lbs. So an extra 12 lbs there. The feet are pretty light, maybe a pound each, so another 16 lbs. 4-6 lbs for the MPPT controller and DC-DC charger.

So I would say less than 100 lbs.

I am very impressed with your system. I do not have the solar panels mounted. Something to consider for the future. I was surprised by the light weight of your Group 27 battery. I have to assume it was a standard lead-acid battery and not AGM. Which I again assume explains the 20 pound difference in our factory provided batteries.

I swapped out my Casita provided 100 amp Interstate AGM battery for two lithium batteries. The AGM battery weighed 71 pounds. Each of my 105 amp lithium batteries weigh 41 pounds. Add another 2 pounds for the battery box and 10 gauge wire. So I upped the towing weight by 13 pounds by switching batteries. I upped my available current from 50 amps to approximately 180 amps. Well worth the 13 pounds additional towing weight in my estimation. So far, my Zamp solar suitcase seems to do a good job keeping the batteries topped off. I must allow that my electrical load has been minimal so far: lights, MaxxAir fan, electric tongue jack, TV on a 150 watt inverter, charging of phone, computer, and other electronics.

[Shocksll]

Originally Posted by Bob Penn

I am very impressed with your system. I do not have the solar panels mounted. Something to consider for the future. I was surprised by the light weight of your Group 27 battery. I have to assume it was a standard lead-acid battery and not AGM. Which I again assume explains the 20 pound difference in our factory provided batteries.

Thanks! Yea,, it was the standard lead acid. I didn’t want to pay to upgrade to agm when i was planning on doing LiFePO4.

[Bob Penn]

Originally Posted by Shocksll

Thanks! Yea,, it was the standard lead acid. I didn’t want to pay to upgrade to agm when i was planning on doing LiFePO4.

Unfortunately, I was not that smart. I did not consider changing batteries until much later. So I paid the upgrade price for the AGM battery. I ended up giving that battery to my nephew for his RV. A large amount of money down the drain for sure.

When I was in the Navy, we had a saying. We called it the "7 P's". It went like this. Proper prior planning prevents p**s poor performance. In my case, the "proper, prior, planning" failed to take place. So I ended up paying the price for it. I place it under the category of "Lessons Learned".

[Perryb67]

Originally Posted by Bob Penn

If I decided to add any additional panels, I will either need to change my solar controller to allow for the additional "amps" or find out if multiple controllers can work together. I am ass-u-ming that the latter is not possible. A myriad of questions then run through my mind as to what is needed to accommodate the extra panels. Based on what you stated, I should hook everything up in parallel. I don't know if my Zamp suitcase system is in parallel or series.

Multiple controllers can work together. Our 100 watt Renogy portable is connected to a Victron 100/20 solar charge controller located in our camper. Our 465 watts on the roof is connected to a different Victron 100/30 SCC. Both are hooked directly to the battery. I've read that some Titanic campers have as many as four SCCs connected to their battery bank. It's done all the time.

If adding solar to your roof it's good practice to purchase a second controller for the new roof panels.

Since you have a Zamp controller hooked to your batteries it doesn't matter if its wired in parallel or series, the output should be 12 volt nominal. I've never bothered to see if my Renogy panels are in series or parallel since their SCC output is 12v nominal.

Enjoy,

Perry

[Bob Penn]

Originally Posted by Perryb67

Multiple controllers can work together. Our 100 watt Renogy portable is connected to a Victron 100/20 solar charge controller located in our camper. Our 465 watts on the roof is connected to a different Victron 100/30 SCC. Both are hooked directly to the battery. I've read that some Titanic campers have as many as four SCCs connected to their battery bank. It's done all the time.

If adding solar to your roof it's good practice to purchase a second controller for the new roof panels.

Since you have a Zamp controller hooked to your batteries it doesn't matter if its wired in parallel or series, the output should be 12 volt nominal. I've never bothered to see if my Renogy panels are in series or parallel since their SCC output is 12v nominal.

Enjoy,

Perry

Perry, thank you for your explanation. Very clear. I have been on fence about additional solar because I did not know if I would need a new controller or if multiple controllers could be used. Your post helped immensely with my understanding of the problem.

[Shocksll]

I’ve added eternabond over the feet to give it a little more holding power and ensure the tape is protected from the elements. This should increase the tensile strength of the feet from 270 lbs of tensile strength to 336 lbs of tensile strength per foot. So my total tensile strength is over 1400 lbs per panel. With a weight of 14 lbs, that’s a 100x safety factor to handle any wind factors. From my research and calculations, 130 mph wind hitting the panel laterally would generate 275 lbs. That gives me a 5x safety factor for what i consider a worst case scenario.

I’ve also added more tethers to my install so if any panels come off they should stay on the casita. I included one around the a/c unit and others around the vent caps. And all of the panels are connected to one another with the idea that it’s doubtful that all 4 panels would come off at one time.

Now that the tape has reached 100% adhesion, we plan on going for a test drive tomorrow. My wife will be pulling the Casita and I will be following to see how the panels are holding up. We’ll increase the speeds of the test until 65 or so mph.

[Shocksll]

Originally Posted by Shocksll

Now that the tape has reached 100% adhesion, we plan on going for a test drive tomorrow. My wife will be pulling the Casita and I will be following to see how the panels are holding up. We’ll increase the speeds of the test until 65 or so mph.

Test went very well yesterday evening. Panels didn't move at all. We are going on a longer trip this weekend which should test it further.

[Perryb67]

Originally Posted by Shocksll

I’ve added eternabond over the feet to give it a little more holding power and ensure the tape is protected from the elements. This should increase the tensile strength of the feet from 270 lbs of tensile strength to 336 lbs of tensile strength per foot. So my total tensile strength is over 1400 lbs per panel. With a weight of 14 lbs, that’s a 100x safety factor to handle any wind factors. From my research and calculations, 130 mph wind hitting the panel laterally would generate 275 lbs. That gives me a 5x safety factor for what i consider a worst case scenario.

I’ve also added more tethers to my install so if any panels come off they should stay on the casita. I included one around the a/c unit and others around the vent caps. And all of the panels are connected to one another with the idea that it’s doubtful that all 4 panels would come off at one time.

Now that the tape has reached 100% adhesion, we plan on going for a test drive tomorrow. My wife will be pulling the Casita and I will be following to see how the panels are holding up. We’ll increase the speeds of the test until 65 or so mph.

Steve,

How many square inches of VHB tape do you have on each mount (4 mounts per panel?).

Thanks,

Perry

[Shocksll]

I bought these: https://rvsolarstore.com/index.php?r...product_id=112

Which are 3” x 1” of VHB tape. They recommend 4 feet per panel for under 100w, and 6 feet for 100-160w. I bought 100w panels but they are the Renogy compact ones which are similar size and weight as an 80w panel. So i went with 4 feet and used eternabond for extra strength and protection.