Adding Solar panels

[Timsttrv]

Hi ,we own a Reflection 315RLTS and are new to the RVworld.Reading and learning mor and more every day. I’m thinking about adding more solar panels but need some input.
Have a Furrion 370 watt panel with Furrion 50 amp solar controller,600 watt max input. Panel specs belowDoes anyone have any suggestions of what panels would be best to use.There is just enough room on top for another 370 watt panel but in series would put me over 600 watts Would there be a better choice finding smaller panels,say 175 or 200 and going series and parallel .

[acoleman43]

Hi ,we own a Reflection 315RLTS and are new to the RVworld.Reading and learning mor and more every day. I’m thinking about adding more solar panels but need some input.
Have a Furrion 370 watt panel with Furrion 50 amp solar controller,600 watt max input. Panel specs belowDoes anyone have any suggestions of what panels would be best to use.There is just enough room on top for another 370 watt panel but in series would put me over 600 watts Would there be a better choice finding smaller panels,say 175 or 200 and going series and parallel .

HI Tim. First, why do you want to add more panels? What are your expectations?

[Jerry J]

Tim,

I did something similar to what you're wanting to do. Our 303rls has a the factory installed 370W panel and a 50A charge controller. I had the dealer install an additional 200W panel. What they did was parallel the two panels (which made since at the time since most panels I've worked with have a Voc of 18V to 20V). However, once I got the trailer home, I wasn't getting the output from the solar that I thought I should be getting. I disconnected the all the solar connections and did some testing and I was getting a Voc of 36V from the factory panel and a Voc of 18V from the 200W panel. When I looked at the factory panel, it looks like it is two panels connected in series, which makes sense if each panel is putting out 18V Voc. ( 18V+18V=36V) So what the dealer did was essentially put an 18V battery in parallel with a 36V battery. Not Good. I'm surprised something didn't burn up or fail. I reconnected the two panels in series with a total Voc of 54V (After verifying the charge controller can handle the increased voltage) and now I'm getting the power from the solar that I think I should be getting.

[TucsonJim]

Wiring different size panels into an array can really reduce the overall efficiency of the array. If you can't use panels with similar voltage and current, you can run the array outputs to two different solar controllers for better efficiency.

This video gives very clear examples of what happens with panels that have different characteristics.

https://youtu.be/jejro4zkl8I?si=rAjby4O6kFX1iz3i

On my new Solitude, the installed a 330 watt panel. I want to increase my array size to at least 2000 watts. However, I can't fit 330W panels into most spaces on the roof. I'm going to remove the 330 Watt panel, and install 10-12 200 watt panels with series/parallel strings and two MPPT controllers.


Jim

[acoleman43]

Wiring different size panels into an array can really reduce the overall efficiency of the array. If you can't use panels with similar voltage and current, you can run the array outputs to two different solar controllers for better efficiency.

This video gives very clear examples of what happens with panels that have different characteristics.

https://youtu.be/jejro4zkl8I?si=rAjby4O6kFX1iz3i

On my new Solitude, the installed a 330 watt panel. I want to increase my array size to at least 2000 watts. However, I can't fit 330W panels into most spaces on the roof. I'm going to remove the 330 Watt panel, and install 10-12 200 watt panels with series/parallel strings and two MPPT controllers.


Jim

What Jim said

Also, installing 2000W of panels (like Jim) without a battery bank that can hold the energy is wasting money. Before you start adding panels, it might be a good idea to what you intend to accomplish with adding panels. You may just be throwing money away without upgrading other parts of the electrical system to use and store the additional energy the extra panels will produce.

[TucsonJim]

What Jim said

Also, installing 2000W of panels (like Jim) without a battery bank that can hold the energy is wasting money. Before you start adding panels, it might be a good idea to what you intend to accomplish with adding panels. You may just be throwing money away without upgrading other parts of the electrical system to use and store the additional energy the extra panels will produce.

BTW, my battery bank is 920 amp hours of LiFePO4 batteries.

Jim

[howson]

Hi ,we own a Reflection 315RLTS and are new to the RVworld.Reading and learning mor and more every day. I’m thinking about adding more solar panels but need some input.
Have a Furrion 370 watt panel with Furrion 50 amp solar controller,600 watt max input. Panel specs belowDoes anyone have any suggestions of what panels would be best to use.There is just enough room on top for another 370 watt panel but in series would put me over 600 watts Would there be a better choice finding smaller panels,say 175 or 200 and going series and parallel .

Here's a thread on what I did on my '19 315RLTS (and why): https://gdrvowners.com/forum/solar/1...n-2019-315rlts

Note there wasn't a OEM-supplied solar panel or controller to contend with in my trailer.

If I may suggest -- best $15 you can spend is to get a copy of Will Prowse's book Mobile Power Made Easy. Read it before potentially spending a wad of cash on a system that may not perform to your expectations. More info here: https://www.mobile-solarpower.com/the-book.html

Howard

[Timsttrv]

Thanks for all the input , I’m in the reading and learning process ,so any information is greatly appreciated. As it stands for now the 370 watt panel will run the 12v fridge and other parasitic draws 5-6days and that’s only 6-7 amps. I have checked power going to battery with sun straight overhead and had 13.6 amps ,with 7.1 from panel.
I put a 200 amp lithium battery in when the rv left the dealer, hopeing to get 3 days or so of boondocking but don't see how that can happen without adding more panels for now.
Future plans are to have 1200 watts in panels but for now would it be feasible to add another 370 watt panel and incorporate them into a larger system later on.I spoke to Furrion about the wattage and if the panels are wired in series the controller wouldn’t be damaged from the extra 140 watts it would just max out at 600 watts,or would the 2 panels be better in a parallel situation to keep wattage down and double amps

[Timsttrv]

Another note ,I had poster earlier about my controler not going to bulk stage and since figured out from reading post from this forum that it’s working right but as the sun started to move across the sky ther we’re a couple of rather tall trees behind my house that the tops were shading my panel from say 2:00 on

[TucsonJim]

Tim - You might actually be fine with one more panel and your current battery bank. I had 300 amp hours of batteries on my last rig and 800 watts of solar. I had a DC refrigerator, and ran the television, laptops, and Starlink through a 2000 watt inverter. My maximum usage was 160 amp hours during a 24 hour period. And of the time I ran around 130-140. You sound like you'll have very similar results.

And if you need just a little bit more, you can always add 100-200 watts of portable panels (with their own controller). And this will also be helpful if your main panels are shaded.

Jim

[Country Campers]

I would not add a second 370 watt panel at this time, they are expensive and large as you know. Adding portable panels as TucsonJim mentioned above would be a better option. You could also add a second battery as you are going to want that anyhow. A small generator is also handy to have when dry camping. Although I have not needed mine yet it goes with us every time we are dry camping. Just a few thoughts.

Brian

[acoleman43]

Thanks for all the input , I’m in the reading and learning process ,so any information is greatly appreciated. As it stands for now the 370 watt panel will run the 12v fridge and other parasitic draws 5-6days and that’s only 6-7 amps. I have checked power going to battery with sun straight overhead and had 13.6 amps ,with 7.1 from panel.
I put a 200 amp lithium battery in when the rv left the dealer, hopeing to get 3 days or so of boondocking but don't see how that can happen without adding more panels for now.
Future plans are to have 1200 watts in panels but for now would it be feasible to add another 370 watt panel and incorporate them into a larger system later on.I spoke to Furrion about the wattage and if the panels are wired in series the controller wouldn’t be damaged from the extra 140 watts it would just max out at 600 watts,or would the 2 panels be better in a parallel situation to keep wattage down and double amps

The typical rule of thumb for solar/battery is solar is twice your battery bank. In other words if you have a 100AH battery, a 200W solar panel should work good. If you have a 200AH battery, 400W panel should be fine. In other words, as you increase your solar, you should probably increase your battery bank and vice versa.

Our system is 1260W panel array and 10.2KWH battery bank. We are short on our solar array by about 800W (from where I want to be). Like suggested previously, portable panels are a great option. I have an additional MPPT controller for another 800W of portable panels to get my the 2000W I want. With just the 1260W, when the sun is out, we have gone almost 2 weeks without any hookups or generator usage. Honestly in that environment we could have gone indefinitely. We even ran the AC a few hours a day off the batteries.

Another trip with the same exact setup, we lasted just 3 days before we had to pull out the generator to charge the batteries. We have overcast skies and tree coverage every day which meant our batteries were just being depleted without enough sun to charge them.

When you are planning your upgrades, I would not leave out a generator

[Timsttrv]

Thanks got on top with a tape measure today and another 370 watt panel will not fit anywhere,43x61huge with mounts. The portable panel would help but I’m think I’ll look into a couple of 100-200 that will come close to matching the 370 numbers. I know later when I do start with more panels I will go with a Victron Connect solar controller so if adding anything now I want panels that I can add to later and work with it.I have a small 2000 watt Honda generator now but was looking at a 4000 today