My RV Build: 600 watt Roof Mounted Panels and 400 watt ground mounted Panels

chrisski

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I'm getting close to turning on the switch for my 12 volt 1000 watt with 600 watts roof mounted and 400 watts ground mounted PV build.

This is the 400 watt portion. It's:

four 100 watt Lion Energy portable panels hooked in parallel,
400 Watt Build 100 watt portable Panel.jpg
The panels are Hooked with Anderson Powerpoles
400 Watt Build Anderson Powepole.jpg

a Circuit Breaker box with four 10 amp circuit beakers for each panel, a combiner, that will attach to a folding board,
400 Watt Combiner C-B Box.jpg
400 Watt Combiner Mounting Board.jpg

a 6 gauge extension cable (not pictured),

which attaches to 30 amp circuit breaker and finally a 100/30 Victron Charge Controller.
400 Watt Power Board.jpg

I'll post more later.
 

Supervstech

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Power pole connections aren’t weather tight, nor are they locking...
 

chrisski

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Those “Anderson Poles” are an example of getting something because its a good deal and designing the system around it. From the Combiner to the RV and RV to Circuit Breaker box are MC4 connectors.

I don’t like the Anderson Poles either, and I will change those to MC3 or MC4 connectors. Until I do, I think I’m going to secure them shut with duct tape. I will probably have these Anderson Poles on for a couple of days before the swap.

The Lion Energy Panels came with a 1 pair wire, 2 conductors inside a single wire. The conductors are pretty skinny, probably 16 AWG, and I did not want to cut off the Anderson Poles and Install MC3 or MC4 wires on something so skinny. I think I want to remove the entire cable from the diode box and solder on my own. The Lion ENergy Panels are rated four in parallel. This swap is on my to do list, probably the first thing after I throw “Throw the switch.”

The panel was my first purchase, and “I got a really good deal on the first,” and A somewhat good deal on the next three. I found out when you Get a good deal on one small part of one component, it limits you on what you can do, instead of Putting everything down on paper first.
 
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Supervstech

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The panel was my first purchase, and “I got a really good deal on the first,” and A somewhat good deal on the next three. I found out when you Get a good deal on one small part of one component, it limits you on what you can do, instead of Putting everything down on paper first.
truer words were never spoken.
 

chrisski

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I installed the Master off switch for the battery and moved the ANL fuse for placement of the Master Off Switch today:
Master Off Switch.jpg
I have 1/4" plastic on the back of the switch. The switch itself is rated for 350 amps. I decided on 200 amp ANL fusing. Using the pass through storage under the Master bedroom for this RV build, and this Battery banks and Power Boards are taking up 1/2 the storage area. Deciding where to put the switch was especially hard with the fusing needing to be before the switch.
 

HRTKD

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Looking good! Nice job on labeling everything.

I am going to quickly tire of deploying/storing my two 320w panels. They're heavy enough that it's a two-man job getting them in/out of the trailer. But they work great! No complaints about the performance, that's for sure. They kick butt, more watts produced than the rooftop panels.
 

chrisski

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more watts produced than the rooftop panels.
I expect the same with my ground mounted 400 watt ground panels. The roof panels did not produce the short circuit amps I had expected from the sticker, I think it's because they are flat and dusty. The ground mounted panels, a different brand, have put out the short circuit amps I expected from the sticker any time they're bright and pointed at the sun, except for dawn and dusk when it starts to get dark.

Slight chance of Rains and definitely clouds expected this weekend, and I may delay taking it out the first time until next weekend. This first time out is to program the two SCCs and fine tune some other items.

For the labeling, I plan to put it into a little manual in case I ever sell this trailer. I need someone besides myself to understand it, even if its my son or daughter that borrow the trailer for the weekend.
 

HRTKD

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I expect the same with my ground mounted 400 watt ground panels. The roof panels did not produce the short circuit amps I had expected from the sticker, I think it's because they are flat and dusty. The ground mounted panels, a different brand, have put out the short circuit amps I expected from the sticker any time they're bright and pointed at the sun, except for dawn and dusk when it starts to get dark.

Slight chance of Rains and definitely clouds expected this weekend, and I may delay taking it out the first time until next weekend. This first time out is to program the two SCCs and fine tune some other items.

For the labeling, I plan to put it into a little manual in case I ever sell this trailer. I need someone besides myself to understand it, even if its my son or daughter that borrow the trailer for the weekend.

I started a narrative for my system. Unfortunately, it's going to need a table of contents.
read.gif
 

chrisski

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Here's a couple of pics of the frame grounding for the inverter and SCCs. This is not the Battery negative, but more of a case to frame ground.
Frame Ground-1.jpgFrame Ground-2.jpgFrame Ground-3.jpg
And Here's a couple of pics of the Battery Box:
Battery Box 1.jpgBattery Box 2.jpg
I planned two hours today to do that. Took me all day.
 

chrisski

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Although it was a cloudy day, I loaded the batteries in.
Cloudy  Day.jpgBattery Box Loading.jpgBattery Box Loaded.jpg
I powered the SCC, the panels, then turned the inverter on. I peaked at 59 watt production with 600 watts of panels, and was usually a lot less. A total of 60 watt hours was produced.
Inverter Remote and Battery Monitor.jpg
I had the 600 watt panels on the roof, and parked in the storage lot it was the worst of possible production: panels facing opposite the sun with things to shade them like AC units and pipes. The panels are made to face South, and they were facing East. Here's a couple of pictures of the panel and the layout:
100 Watt Panels Tilting Mechanism.jpgTilt Mounting Rail.jpgPanel Layout.jpg
In the diagram, the top should be facing South to get the most sun. Done over again, I'd mount the panels differently, horizontal in the pic, not like it is vertical, but I will get enough power. In the Blank spaces, I plan on putting around 350 watts more panels.
 

chrisski

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Continued to tweak my system before I take it to dry camp by the lake in a few days.

100 Watt Solar Panels set up.jpg
I had both roof panels and portable panels set up, and I got a lot more power produced on a sunny day than yesterday when it was cloudy. I made 1 KWH of power today. I did notice that the 600 watts of roof mounted panels fed into the SCC #1 produces about 30% more power than SCC#2 that fed the 400 watts of ground mounted panels. I did notice in the sunny day with batteries full, the charge controllers don't pull near the solar panels full rating. Makes sense, but I did not expect that.

At first, the few minutes it took to get to the battery charged was the only time I saw this, and with no load on the system, it went into a float mode where it pushed about 1 amp to my 12 V 458 AH battery pack. I turned the inverter on, and it consistently drew 1 amp with no load, which matches the instructions. I turned a few devices on, a 18 volt Milwaukee battery charger, which pulled a little more amps. I turned to AC fridge on and the inverter started pulling 300 watts. The Large screen TV added another 20 watts to the inverter. With those devices on, as long as it was sunny out, the battery remained at 100% and the panels kept enough amperage flowing into the system to top it off.

At one point, I had the RV's converter on, which is a big no-no. That ended up pulling 700 watts, and that plus the 300 watt fridge was taking energy out of my system quicker than the panels could return it. As soon as I noticed the converter was on, I shut it off.

I got an IR gun to measure heat produced, and I could find no hotspots. I measured it when pushing 300 watts from my 2000 watt inverter. I was expecting something, but got no hotspots, so I think oversizing the inverter and going with 4/0 wire certainly helped keep the heat down.

Battery temp was fairly consistent at 75° F through the day, which was two or three degrees above ambient temp.
 

HRTKD

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what determines wire size from panels to controller?

Wire size is determined by acceptable voltage drop. Use this calculator:

As far as PV panel to charge controller, the wire size is often determined by what's available. Wire that is PV rated is commonly available in 10 to 14 gauge.
 

chrisski

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what determines wire size from panels to controller?
For a detailed explanation, look here https://www.calculator.net/voltage-drop-calculator.html. Scroll past the calculator and tables and there’s good instructions on the bottom.

I used that calculator as one factor to determine wire size. I then checked wires for ampacity, max amps, at the maximum temp I wanted the wires running at,
 

chrisski

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hey why did you install circuit breakers for the panels ? never seen that ?
So much easier to troubleshot with circuit breakers.

I’ve found my roof panels are maintenance free because nothing moves on them. I’ve found my portable panels need almost daily maintenance. THis is because they are set up and put away every five days, and also I move them 3 times a day to maximize solar production. The maintenance to those panels is mostly finding which one has a bad connection.

Panels can be unplugged at the MC4 or Anderson plugs also, but the circuit breaker is so much easier. My Midnite Solar DC circuit breakers are rated for thousands if actuations.

In theory, my 4 portable panels need circuit breakers because they are set up in parallel and all four together exceeds the max series fuse rating. However, in theory, my roof panels are 3S2P, and they would not exceed the max series fuse rating so I don’t need them for that, but I would like to add a third set of panels, and that would exceed the max series fuse rating, and I’d need it.

Also, for the roof panels, who likes to climb on a roof to troubleshoot the panels? The circuit breaker lets me do that from the ground.
 

chrisski

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Here are some pictures of the power production, pretty much at max production for the day.
85C3B8D0-F521-411E-A215-33ABAD44337E.png
This show my 1000 watts of panels pushing 40 amps of power into the batteries. It will truly max out at 45 amps of production around 1pm if the SCCs stay in built do not slip to absorption or float. If I parked for solar production instead of view of the lake, I’d see 60 amps at max production. Who wants to get a view from the window of a parking lot instead of a lake, especially in the desert southwest?

D9CB3DD5-5B8E-4658-9CD5-22390DDD220A.png
This shows my four 100 watt panels that are set up in parallel at max production, 17.7 volts and 21 amps sent to the charger and changed into 14 volts and 26 amps. This SCC can only output 30 amps, so I could add another panel, but production would be clipped at 30 amps. I’m happy with production. Downside is its windy in all the places I’ve been and I need to chain them to keep them blowing away and lie them flat to keep from toppling over when the wind picks up and the weather underground does not predict the winds in the valleys I stay at.

EF1E7923-43F0-4A06-8805-D596A6B897E2.png
This photo shows my flat panels on the roof. THese six 100 watt panels are set up 3S2P, with 54v producing 4.9 amps of current, that get changed to 14 charging volts and 18.7 amps of current. If these panels were oriented for solar output, you’d see 10.0 amps of current instead of 4.0, which would mean close to 36 amps of current to the batteries From this SCC.

On this trip, I parked for a view and I decided not to align the roof panels to the south. Because these panels are on the north side of the RV, there’s shadows from the air conditioners across them, and also I lose about 40% output by having them flat and not tilted. I don’t tilt them because I’m afraid of these being torn off the roof on some of the windstorms we’ve had. The portable panels have really helped with production.

My batteries can take 60 amps of charging current, which between both SCCs and if I oriented the RV into the sun and tilted the roof panel I would get. Sometimes though, you just have to enjoy the views and sacrifice the power production, especially since I’m not the only one enjoying this trip.
 

WA5IDX

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Oct 2, 2020
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Nice set up. I have 600 watts of PV panels on my 25 foot Airstream and yes, they are all flat. I did separate them into a 2S3P configuration mostly because of the roof layout. The two panels that are at the stern of the roof are in series and then I connected one off each forward area to one in the "central" area between the AC units. Still conducting tests but this gives me the best chance of having "averaged" maximum (if that makes sense) output during the day.

I don't have any portable panels ( yet) and I'm still working on the LiFePO battery bank ( it will be 4S2P and 570 AHr) total driving a 3Kw inverter an the Victron 100/50 SCC.
 

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chrisski

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I don't have any portable panels ( yet) and I'm still working on the LiFePO battery bank ( it will be 4S2P and 570 AHr) total driving a 3Kw inverter an the Victron 100/50 SCC.
So far, I’ve only used my RV with some of the shortest days of the year, but those portable panels have helped tremendously. When I’m alone, I only use about 10 ah, or 2% a night, but that’s no fun sitting in my trailer all bundled up and when my family shows up we have luxuries like propane heat that draws the most load, and ends up using between 100 ah and 160 ah, or 18% to 28%, depending on the temp.

That’s where I really need those portable panels to push the energy back in the batteries. I keep them printed at the sun moving them three times a day. My 600 watts of roof panels have probably made 40 ah of charge, and the portable panels the rest. I never thought I’d get that much power from those panels.

At peak charging, I can add 15 more amp before my batteries are maxed out at 60 amps charging. I’m thinking of using a larger 300 watt flat panel and making a stand for that. 300 more watts of portable solar would get me my 15 amps to max battery charging.
 
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