Upgraded Solar Install Complete.

[TucsonJim]

2017 Reflection 297RSTS travel trailer. I just finished upgrading my solar charging system from 300 watts to 800 watts. In addition, I manufactured my own tilt panels because I didn't care for any of the commercial versions. During peak sun, I'm hoping for about 50-60 amps of charging per hour. Here are some pics:

[bertschb]

Very impressive Jim! Looks like a great setup. I ordered our new 310GK-R with the new solar package so I'm interested to see how it's all wired. I'm also curious as to how easy it will be add a panel or two in the future.

[howson]

2017 Reflection 297RSTS travel trailer. I just finished upgrading my solar charging system from 300 watts to 800 watts. In addition, I manufactured my own tilt panels because I didn't care for any of the commercial versions. During peak sun, I'm hoping for about 50-60 amps of charging per hour. Here are some pics:

Wow.

Are you planning on posting a parts list along with the "why" related to the choices made? (That would be very helpful!)

[TucsonJim]

Wow.

Are you planning on posting a parts list along with the "why" related to the choices made? (That would be very helpful!)

Yes sir, and a schematic too. But it may take a while... you know how busy us retired guys are.

Jim

[TucsonJim]

Wow.

Are you planning on posting a parts list along with the "why" related to the choices made? (That would be very helpful!)

Hi Howard

I just finished compiling a list of all the the components that I used for the install. This does not include tools and some materials I had in the garage such as romex and some mounting screws. The total price for the solar, inverter and transfer switch came to about $2800.

I included links to the we**ites where I purchased the materials when available. Check out the Excel sheet for more details. There are probably much more elegant solutions to some of my choices, but I needed to stay within budget too. I went with the 100W HQST panels to match what I already had in existing panels for the last couple of years. If I was starting from scratch, I'd probably look at higher capacity panels now.

Materials.pdf

Jim

[howson]

Hi Howard

I just finished compiling a list of all the the components that I used for the install. This does not include tools and some materials I had in the garage such as romex and some mounting screws. The total price for the solar, inverter and transfer switch came to about $2800.

I included links to the we**ites where I purchased the materials when available. Check out the Excel sheet for more details. There are probably much more elegant solutions to some of my choices, but I needed to stay within budget too. I went with the 100W HQST panels to match what I already had in existing panels for the last couple of years. If I was starting from scratch, I'd probably look at higher capacity panels now.

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Jim

Perfect. Thanks, Jim.

I'm going to reveal my ignorance with this question, but it's never stopped me before: why does the MPPT Controller have such a high (150v) voltage rating? Could solar panels (wired appropriately) really approach that voltage level?

Another NEWB question--is there a difference between the solar panels installed on an RV vs the panels on a house?

The picture below is (for now) my "starting point". It is from another site and it is also a 315RLTS. They used a Victron 100/50 MPPT and 3 Hi-Tech 200 Watt monocrystaline solar panels.

But for now I've got too many other projects in the hopper. Still a lot of learning to do before I pull the trigger. Maybe I'll wait to do the install until I'm somewhere near Tucson, Arizona so I can have a well-known moderator lend me his technical assistance.

[TucsonJim]

Excellent questions Howard.

I'm two strings of four panels in series. Then the two strings are connected in parallel. The panels are 100W Poly each. This gives me an input voltage of 80 volts at approximately 10 amps. The controller converts the 80 volts to 14 volts for bulk charging. So 80V/14V = 5.7. Then, you multiply the 10 amps times 5.7 to get 57 amps. The limiting factor is not the voltage, but the current. At 57 amps, I went with the 60 amp controller.

Using this information, I wanted to confirm I made the correct selection. Victron has an MPPT calculator that you can plug your numbers into. I'll provide the link below. For the calculator parameters, I used the following:

Victron Solar Modules - 100W-12V Poly
Series - 4
Parallel - 2
PV Module Temperature - Min 0C, Max 70C
System Voltage - 12V
City - Tucson AZ

This gave me six options to choose from. I selected the Smart Solar (Blue tooth) MPPT 150/60 TR - 150 is the max voltage, 60 is the max current, and TR stands for terminal connections (vs. MC4).

Check out the calculator when you get a chance at:
https://mppt.victronenergy.com/

To answer your other questions, the panels I selected are the same ones you'd use on a home. I'd strongly recommend against using flexible panels. They don't last nearly as long, and you have to glue them to your roof which makes replacement very difficult.

Regarding that photo. I'm not sure if that was a complete assembly or not. If so, those wires should probably be secured better to keep them from whipping in the wind.

And head on out to Tucson. I'd be glad to "supervise" as long as you provide the IPAs.

Jim

[howson]

Excellent questions Howard.

I'm two strings of four panels in series. Then the two strings are connected in parallel. The panels are 100W Poly each. This gives me an input voltage of 80 volts at approximately 10 amps. The controller converts the 80 volts to 14 volts for bulk charging. So 80V/14V = 5.7. Then, you multiply the 10 amps times 5.7 to get 57 amps. The limiting factor is not the voltage, but the current. At 57 amps, I went with the 60 amp controller.

Using this information, I wanted to confirm I made the correct selection. Victron has an MPPT calculator that you can plug your numbers into. I'll provide the link below. For the calculator parameters, I used the following:

Victron Solar Modules - 100W-12V Poly
Series - 4
Parallel - 2
PV Module Temperature - Min 0C, Max 70C
System Voltage - 12V
City - Tucson AZ

This gave me six options to choose from. I selected the Smart Solar (Blue tooth) MPPT 150/60 TR - 150 is the max voltage, 60 is the max current, and TR stands for terminal connections (vs. MC4).

Check out the calculator when you get a chance at:
https://mppt.victronenergy.com/

To answer your other questions, the panels I selected are the same ones you'd use on a home. I'd strongly recommend against using flexible panels. They don't last nearly as long, and you have to glue them to your roof which makes replacement very difficult.

Regarding that photo. I'm not sure if that was a complete assembly or not. If so, those wires should probably be secured better to keep them from whipping in the wind.

And head on out to Tucson. I'd be glad to "supervise" as long as you provide the IPAs.

Jim

Great info--I had to stop what I was doing and copy/paste your post into my notes. I'll probably be hitting you with a dozen or so more questions by the time I'm ready to give this a go myself.

[howson]

This gave me six options to choose from. I selected the Smart Solar (Blue tooth) MPPT 150/60 TR - 150 is the max voltage, 60 is the max current, and TR stands for terminal connections (vs. MC4)...Check out the calculator when you get a chance at:https://mppt.victronenergy.com/

To answer your other questions, the panels I selected are the same ones you'd use on a home. I'd strongly recommend against using flexible panels. They don't last nearly as long, and you have to glue them to your roof which makes replacement very difficult.

Jim,
When you're get back online I'd appreciate some feedback on your upgrade. Did it perform to expectations?

I've re-read your post numerous times and understand how you came to the conclusion to purchase the 60 TR version. I've also gone on Victron's website and the results repeated with the stated variables.

AMSolar uses (Array Wattage Array * 90%)/Battery Voltage = Controller Amperage. I found Garret's video very helpful:

Using his equation, an 800W array requires a 60A (exactly!) controller.

I find it interesting that Will Prowse's approach is different. He uses the wattage of the solar array and divides by the battery voltage to determine the amperage for the controller. For an 800W/12V system that's 66.7, or 70A controller. The difference in the SmartSolar (Victron) is only ~$50 to go from the 60 to 70, but why spend the money if not necessary? While I find his content interesting, in this case I'll use Victron and AMSolar's equations to determine the controller's max amperage.

Since I have no panels, I'm also considering Zamp Solar's new Obsidian panels. They look really sleek and light. Pricey, but I'm only buying solar panels for an RV once. AMSolar will start selling these soon (I've exchanged emails with Garret) so time will tell on the price vs "sleek look" benefit. Garret already has written that they don't perform any better than Zamp's standard 100W panel.

You added to what was already in your system (panels). If you were starting from scratch, what would you use?

[TucsonJim]

I just returned from 14 days of camping in the Arizona desert without hookups. While there, I had very little internet coverage so I couldn't report on how things were working.
I'm thrilled with the performance of my solar charging system. During the 14 days, I never had to fire up a generator, and we were at 100% state of charge (SOC) by no later than 2:30 every day. Since we were achieving 100% SOC every day, there was no need to tilt our panels. From the 800 watt array, we typically achieved a maximum wattage of 450-475 at solar noon which is typical near the winter solstice. Our typical usage was as follows:

Inverter Power:
Coffee Pot - 1 Pot daily. It was interesting to note that brewing one pot of coffee in the drip coffee pot consumed 18 amp hours of power.
Television and satellite (3 hours nightly)
microwave - 5 minutes daily

12V Power:
Furnace Fan - About three hours daily (10 amps per hour)
DC Compressor refrigerator - 24 hours per day (approximately 65 amp hours)
LED lights - one or two all night during darkness
Phone chargers - 2

From the chart below, you can see our typical consumption on a daily basis. The heavy usage (left side of the chart) was during our 14 days in the desert.

[howson]

I just finished compiling a list of all the the components that I used for the install.

Referencing the material list--did you really use 2/0 wire? Even 2ga is huge for an 800W system for 15'--or am I missing something?

[TucsonJim]

Referencing the material list--did you really use 2/0 wire? Even 2ga is huge for an 800W system for 15'--or am I missing something?

Howard - I used 10AWG on the solar side of things, and 2/0 to wire the batteries to the inverter.