Hey Who Moved My Cheese? - RV-Dreams Community Forum

bigboomer · RV-Dreams Family Member

Hey Who Moved My Cheese?

NWescapee · RV-Dreams Family Member

Looks like a great new home on wheels! Safe travel you two and see you in Q.

bigboomer · RV-Dreams Family Member

Looking forward to seeing y'all in Q!

Safe Travels!

Sushidog · RV-Dreams Family Member

Man, I love your solar set-up. I'm planning on racking mine above my roof AC units like you did, in a couple years, so I can't wait to see a blog entry on the install.

I decided to have 2 battery banks. First I installed a small 12v bank of 2, GC-2s with 620 watts of panels mounted on the side of my rv that I can raise to different angles toward the sun as needed. I wanted to save my roof space for something similar to your system for the heavy lifting (electrically speaking), using 9 panels (in 3 arrays) instead of the 10 you used. I'll have to figure out how to attach pics to show you my current set-up, since tinypic, my previous image hosting site, went out of business. I have boondocked with it for about 5 months so far, and it has proved adequate for our humble needs, reducing our supplemental generator use to AC and microwave, with only minimal, rare charging.

There are 2 differences between your system and my planned rooftop system.

1. First is that I plan on mounting the first 2 panels so that they attach directly to the roof in the front, to prevent air from getting under the panels and trying to lift them as I travel down the road. They will meet the other 7 flat mounted panels like yours are mounted. My current height is only 11' 9" and I plan to keep it under 12 ft., so shouldn't have any bridge clearance problems. Have you noticed any adverse handling problems so far?

2. I plan on making this a 48v system to power a super high efficiency 48v DC mini-split heat pump mounted on the rear of my MH. I will also power a 3kw or so whole house inverter off of this battery bank, which will have about half the usable AH of yours. I already have a small 12v, 600 watt PSW inverter for my entertainment center and computer use, which I will retain as a back-up.

I see you used simpliphi lithium batteries. Did you get them from N Ariz wind and solar? I know they promote this brand. This is where I bought my first 2 panels. I'd like to be able to afford these batteries but will be going with cheaper ones for now, maybe even a bank of 8, GC-2 FLAs to start as a "learner set" before I bite the bullet, so to speak.

Did you mount your solar rack down the center of your RV or off to one side? I plan on mounting mine offset to driver's (port) side both to provide a walkway and so as not to cover my TV antenna, impeding reception.

Thanks,

Chip

bigboomer · RV-Dreams Family Member

Thanks Chip. Looks like you are well on you way an awesome system as well. We wanted the ability to run everything including the A/C's on the solar and batteries only. I installed the panels down the center of the roof for aerodynamics. They re wirwd in two sets of 5 series to push higher volts into the charge controllers and more efficient wiring. We went with Simpliphi for several reasons. They are truly Made in the USA. Engineered, manufactured and assembled here unlike most of the start ups which use Chinese cells and are Assembled here. They also offer a 10 year warranty at 80 % DOD. We have 604 amps at 24 volts, 15.2 kWh. We have been off the rid since 10/31 running A/Cs, convection microwave, furnace, and everything else under the sun....only been able to get the batteries to 50%... We will be posting a blog on the build shortly. Good luck with your design!

Sushidog · RV-Dreams Family Member

Thanks for the reply, Bigboomer!

At only a 50% discharge those USA made lithiums should last 20 years or more.

I'm planning on 240ah at 48v of FLAs (remember I already have 235ah at 12v which I'll be keeping.) These should last at least 4 yrs if cycled at 50% and recharged daily.

Hopefully by then Lithiums will be more affordable. At their current price, they are at about a 25 year break even point compared to FLAs with the same usable ah.

I get it, lithiums are more efficient, lighter weight, etc., but it's hard to justify spending 3 times the cost of the rest of the system on batteries alone.

Here's a couple pics of my current side-mounted array. This winter I'm planning on adding a couple long gas struts to make them easier to lift.

I know what you are thinking. No that's not Vanna White, that's my DW, Cindy.

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P0-C6G4wqHvUHn2nNQRNeobuC7EMi0ahLPsfQEiL

LarryW21 · RV-Dreams Family Member

“to prevent air from getting under the panels and trying to lift them as I travel down the road”

IMO a non-issue. I have yet to see a solar panel along the road or talk with an RVer who lost a panel.

bigboomer · RV-Dreams Family Member

Have to agree Larry. Aerodynamics of will usually push the air up and over the roof and panels. We have been even seen very high 50+ mph winds come out of nowhere in the desert when we used to tilt the panels and they would raddle but never come loose or off.

Sushidog · RV-Dreams Family Member

I have rather tall AC units that protrude 12" off the roof. I plan on racking my panels 1 inch over their plastic housings - maybe even removing the plastic housings to give them more air circulation to reduce heat buildup, improving their efficiency, since the solar panels themselves will provide a great shade for these units. This means I must rack them 13" of the roof, which gives me sufficient clearance over my 4 roof vents too. It doesn't look like your rack is quite that high from the photos, as you have more modern, low profile AC units.

This is why I plan on mounting the first two panels on an angle with the leading edge of the panel attached directly to the roof and the trailing edge at the height of the other panels, which will remain level with the roof. This will put these first 2 panels at a gentle angle of 8.63 degrees from horizontal, to ease the airflow over the others. As a side benefit, it will allow rain to naturally rinse the dust off these panels, reducing puddling and dirt buildup, possibly reducing the intervals I must climb the ladder, stand on the roof and clean the panels. This is what I like about my side mounted panels. When I let them down and fasten them vertically on the side of my MH, which I do every 2 weeks or so to travel, I can routinely and easily clean them while standing on the ground with the same telescoping squeegee/scrubber tool I use to clean my windshield (washed clean first, of course) to maintain their efficiency.

I'm thinking on building the rack out of 1 1/2" x 1/16" thick 6063 - T5 angle aluminum, with 1" x 1/20" aluminum bar stock used for cross bracing both fore and aft and side to side at the front and rear of each panel for rigidity. I won't be mounting the panels by the edges, but with the inner mounting holes, because according to the panel manufacturer's specs, this position is provides the highest panel load rating. I mounted my side panels utilizing both inner and outer pre-drilled mounting holes with light weight, 6063, 1" x 1/20" rectangular stock. It has proven to be very sturdy, but I try to take it down when wind gusts get over 40mph or so, for safety sake, just as one would an awning. I will soon install air struts to help lift the panels and provide even more support. I plan to reinforce the outer rectangular bars supporting the array with 1" x 1/16" aluminum angle of the same specs, bolting the air struts through both the reinforcement and the original bar stock, to increase its rigidity and safety in high wind conditions.

Chip