400w solar on a 17ft Casita

[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. 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 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.

Right now they are all in parallel but am considering testing to see if going with 2 in series and then parallel would give me better performance.

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

 

[camelCase]

All parallel might be best with the shading you're always going to get with the AC unit in the middle of your East/West configuration.

 

[shocksll]

All parallel might be best with the shading you're always going to get with the AC unit in the middle of your East/West configuration.

Yea, that's what I was thinking which is why I started out with parallel. But I am curious to see the impact of the AC unit if I went series/parallel. Also, with my existing wiring, switching to test series is an easy test vs wiring for series and testing for parallel.

 

[richard cabesa]

Your install looks good considering the space you have to work with on the Casita.

I would though, wire the two panels on each side of the trailer in series and then parallel with the other side.

Look at your first picture and the shadows presented. Your monitor says the screen shot was taken at 1:36 PM. I asume by the shadow that the right side of the picture is facing West. I would bet a very large part of that 300 watts is coming from those West side panels. In another hour or so, the East side panels will be in shadow and producing very little. But, iin the morning they would be rocking like the West is now.

In short, I think you would get a better total daily gain by going 2S2P

 

[shocksll]

Your install looks good considering the space you have to work with on the Casita.

I would though, wire the two panels on each side of the trailer in series and then parallel with the other side.

Look at your first picture and the shadows presented. Your monitor says the screen shot was taken at 1:36 PM. I asume by the shadow that the right side of the picture is facing West. I would bet a very large part of that 300 watts is coming from those West side panels. In another hour or so, the East side panels will be in shadow and producing very little. But, iin the morning they would be rocking like the West is now.

In short, I think you would get a better total daily gain by going 2S2P

Thanks for this. One consideration is that since this is on an RV, I won’t have complete control over orientation all the time. So i could configure things to work best in my driveway but i don’t want it to negatively impact my charging while camping.

If my camper was oriented 90 degrees, would you still suggest the 2s2p?

Thanks.

 

[TomC4306]

I think this is an excellent example and deployment of parallel panels. I'd be thrilled with 300 watts from 400 worth of panels given the geography. Experimenting might be fun but I suspect you'll come back to what is currently working. Well.

 

[shocksll]

I think this is an excellent example and deployment of parallel panels. I'd be thrilled with 300 watts from 400 worth of panels given the geography. Experimenting might be fun but I suspect you'll come back to what is currently working. Well.

Thanks and the 300w didn’t stay long but i was also surprised and excited to see it. Given my setup I figured the most I’d ever be able to see was 320w.

I don’t have a ton of data so far but i would say i can easily get over 200w on a normal basis for several hours during peak sun.

I ran a high load one day which forced the solar to operate at 100% and I got over 1000w for the day. I think in a more open spot i could have had more.

 

[Europa]

My solution a bit of a different approach. This is only to power the 12 volt in the casita.
(1) 330watt panel
(1) Victron Battery protect 65Amp
(1) Victron Smartshunt and temperature sensor
(1) Victron SmartSolar MPPT 100/20
(1) Gyll 12v/100ah Lifepo4

If i need to run my AC i plug my Casita into my F-150 Battery Pack. A 24/3000 watt inverter wired to 300Ah @24v. charged up by 630 watts mounted on the pickup bed and another 315 watt to a removable roof rack over the cab. I another 315 watt ground deployed panel in the truck bed when needed. See previous post on truck specs.

 

[shocksll]

My solution a bit of a different approach. This is only to power the 12 volt in the casita.
(1) 330watt panel
(1) Victron Battery protect 65Amp
(1) Victron Smartshunt and temperature sensor
(1) Victron SmartSolar MPPT 100/20
(1) Gyll 12v/100ah Lifepo4

If i need to run my AC i plug my Casita into my F-150 Battery Pack. A 24/3000 watt inverter wired to 300Ah @24v. charged up by 630 watts mounted on the pickup bed and another 315 watt to a removable roof rack over the cab. I another 315 watt ground deployed panel in the truck bed when needed. See previous post on truck specs.

Wow, that panel looks massive. Do you have more information on your install? Did you use VHB or bolt, any other pictures, etc.?

Just curious about combining the the battery protect with a LFP. With the LFPs BMS, wouldn't the battery protect be redundant?

 

[Europa]

As an engineer protection of the system is paramount. I simply do not trust the manufacturers low temp cut out. the battery protect at $40 is my battery isolation switch now via Bluetooth.It was originally to protect the lead acid that lived here prior to the lithium upgrade.
Stainless bolts sandwich butyl tape and a good dose of lap sealant covered by Eterna bond tape..it might be enough. lol... I got caught in that Texas super storm last February and no leaks then or ever, going on 3 years now. Also the storm in NY again good. Added benefit is I have a rain guard for my Fantastic fan.

 

[richard cabesa]

Thanks for this. One consideration is that since this is on an RV, I won’t have complete control over orientation all the time. So i could configure things to work best in my driveway but i don’t want it to negatively impact my charging while camping.

If my camper was oriented 90 degrees, would you still suggest the 2s2p?

Thanks.

I can't say for sure. Looks like you could swing it around and test it out.

My system is on a roof that slopes off to each side but much less than your positioning. I do though have the A/C very close and an antenna that shadows. I did two series on each side but used two smaller charge controllers to keep them separate. I can see the difference in harvest morning to afternoon from side to side

 

[Bluedog225]

I don’t know that a calculation based on only lateral resistance is the way to go given the way those are mounted. Hope it works out. A safety line for catastrophic failure might be a good idea and help out someone driving behind you.

 

[shocksll]

I don’t know that a calculation based on only lateral resistance is the way to go given the way those are mounted. Hope it works out. A safety line for catastrophic failure might be a good idea and help out someone driving behind you.

Well, the forward resistance is so small because it’s only the shortest edge of the panel. So i was trying to look at the worst case scenario which is a lateral wind. I did add safety lines connecting the panels to each other and to some hard points on the trailer.

 

[richard cabesa]

Yes the frontal force is small. I think I remember 16 lbs. / sq. In at 60 mph when I was figuring mine. Maybe 5-6 lbs of force.
Think about holding your hand out the window going down the highway. It’s not that hard.

But with that said. I have 201,600 lbs of adhesive strength using 3M 5200 (the devils glue) holding my six 100 watt panels on the fiberglass roof.

 

[shocksll]

I ended up making a video with more details of my install:

 

[shocksll]

I've been asked by several people about a wiring diagram. So here's some diagram schematics that I made. One is what the wiring looked like from the factory for the components that I touched. The second is what it looked like after my changes. I didn't include fuses and bus bars and such on the diagram, just the components and how they are connected.

See here for a higher quality PDF: https://1drv.ms/b/s!AkBQeJQSZIj0xr8CON941Sl0S-a1xg

 

[shocksll]

For those interested here also is my cost breakdown.

I did all the labor myself so the all in cost for us was around $4000 which includes the components but also the tools, wires and other items needed for installation. The breakdown was:

Battery monitor and wiring, etc. - $270
DC-DC charger and wiring, etc. - $420
AC-DC converter - $265
Batteries - $1930 themselves and $200 for wiring
Solar panels, controller, mounts, wiring, tape, etc. - $1000

 

[jrgandelg]

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. 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 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.

Right now they are all in parallel but am considering testing to see if going with 2 in series and then parallel would give me better performance.

Excited to see how much this will extend our boondocking capabiliti

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. 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 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.

Right now they are all in parallel but am considering testing to see if going with 2 in series and then parallel would give me better performance.

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

Hello, thank you for this post, will be copying this panel design on my mom's 2017 17' spirit Deluxe. Two questions:
1. Did you test the 2S2P suggestion and was there an advantage to charge time, or was full parrellel the better option for unpredictable sun angle?

2. I don't want to install the wildkat converter, instead I plan to install a changeover switch from the camper dc, routing camper dc 12v to a renogy 40amp dc to dc lithium converter, when shore power is in use to charge the batteries to 100%. Do you see this as a viable solution, in place of the wildkat converter?

 

[shocksll]

Hello, thank you for this post, will be copying this panel design on my mom's 2017 17' spirit Deluxe. Two questions:
1. Did you test the 2S2P suggestion and was there an advantage to charge time, or was full parrellel the better option for unpredictable sun angle?

2. I don't want to install the wildkat converter, instead I plan to install a changeover switch from the camper dc, routing camper dc 12v to a renogy 40amp dc to dc lithium converter, when shore power is in use to charge the batteries to 100%. Do you see this as a viable solution, in place of the wildkat converter?

1. No, I never tested that. I've gotten pretty good results out of my panels in parallel. Last May I took a trip from Charlotte, NC to Wyoming and back. During that trip we only had hookups for 2 of our 19 nights. We spent several nights at Walmart, rest areas and tent sites. Our 400w solar kept our batteries topped off every day. Not a single day passed without us getting to 100%. We averaged 50Ah a day for usage with one day using close to 120Ah because I ran our A/C for a while.

2. It sounds like that might could work but i'm not even sure it's needed. Replacing my converter with the wildkat to be lithium compatible has to be the biggest money waste I’ve done on my trailer so far. I feel this way because:

A. Since adding the rooftop solar, when storing my Casita in my driveway, I now don’t plug it in because the solar keeps the batteries charged.
B. The wfco converter I had would have charged my batteries to 80% which would have been fine for us since the solar can bring it to 100%.
C. I have since installed an inverter and to simplify the setup, I bought an inverter with a built in transfer switch and charger. The inverter can charge many different battery types and can actually charge up to 80A which is pretty fast. So now I have a converter that I upgraded which I have turned off and is literally doing nothing for me.

If you are interested in hearing more about my inverter install, I have a video located here:

 

[featherlite]

ShocksII,

I enjoyed watching your videos. I bet you love your solar system and your rig. However, I would replace that 30 amp breaker you use to disconnect your panels. They have notorious failure rates. Better to upgrade to a Blue Seas or equivalent breaker ... better yet, a DC rated disconnect switch.

In any event, enjoy!

Edit: Assuming you have four panels wired in parallel, did you install a fuse for each panel just before the location where you combined the panels?