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acoleman43 -- where's the wiring on those solar panels? The mounts look the same as the one's I used...which means it's near impossible to get under the panels once screwed down to the roof.
Your description of the sealant is spot-on, too. My sneakers still have evidence of the blasted stuff.
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acoleman43 -- where's the wiring on those solar panels? The mounts look the same as the one's I used...which means it's near impossible to get under the panels once screwed down to the roof.
Your description of the sealant is spot-on, too. My sneakers still have evidence of the blasted stuff.
I have little kids with little arms I am counting on being able to grab the wires from under the panels...or, I'm in trouble
Panels are now wired and functioning. 1260 total watts of panels. Yesterday I was able to get around 900W from them with a very slight cloud cover around 4:00 PM. It was showing just under 60V. I have seen (and felt) as much as 70V so I am hoping to see 1000W+ with no cloud cover.
I don't like seeing battery temps over 100 degrees...BMS temp sensors were all under 100 degrees. Not sure which is more accurate yet. I will install some small fans to assist in air movement and hope that helps.
This morning at 10:30 I was seeing 730 watts with partly cloudy skies.
Something to consider when wiring panels: Make sure you don't come in contact with the exposed wires from the panels. It doesn't feel good. Cover the panels or don't be stupid like me and make sure you are clear of the wires.
After installing all 4 batteries I wanted to run a test. I turned off solar array, unplugged shore power, and waited a couple weeks for the batteries to fully discharge. It was a slow discharge, but, this morning, the voltage finally dropped below 25. As you can see below it dropped to much lower than 25 volts (22.61 volts).....but continued to discharge.
The BMS of each battery has cell undervoltage protection set to 2.5V. As long as all 8 cells in each battery are over 2.5 volts it will continue to discharge. (see BMS screen shot below)
This is not optimal (note the cells are not balanced well when the voltage drops this low), but, in a pinch, it's good to know that the batteries will continue to discharge after the battery is technically dead.
This is a huge advantage of lithium batteries in my opinion.
I spent some time finishing the hatches today. I'm not much of a fabricator...for me it turned out pretty good. I do have some caulking to do, but that's about it.
I also ran another "test". I started the air conditioner at about noon on "low cool" to maintain 80 degrees. I also charged my phone, used the awning, had some lights on. I turned the AC off around 8 PM. Because it was a relatively sunny day it only drained about 20% of the batteries for 8 hours of AC. Total energy consumption was just under 6 KWH and the panels produced 4 KWH during that time for a new "loss" of about 2 KWH (or almost 1 battery).
This is encouraging. I also have a solar port on the side of the RV for a second MPPT charge controller that can handle another 800W if needed which would have increased solar production to around 6.5 KWH.
I finally had a chance to test the new system in Big Bend. None of the campsites we reserved had any hookups. The goal was to NOT use the generator for 9 days in a row, and we did not use the generator at all.
Originally, my energy audit showed we used about 3KWH of energy per day (this does NOT include air conditioning). I designed the system for this usage (however, I wasn't able to fit as many panels as I had planned).
We only used the air conditioner for about 5 hours on day 3.
With the exception of the air conditioner, we used all electric appliances as if we were plugged into shore power. This includes microwave, electric kettle, water heater, lights, charging devices (phones, laptop, Milwaukee tool batteries, Gameboy batteries, toothbrush, headphones, etc), water pump, etc
Average daily power consumption: 2335Wh
Max consumption: 6970Wh (air conditioner day)
Average daily solar yield: 3082Wh. Each day provided about 10 hours of productive sunlight. However, the morning and evening light yields were very low. Average yield during productive hours was about 600W (from 1260W PV array. The colder temperatures from a cold front provided slightly higher yields - and provided 1182W high).
Average Max PV power: 845W. High Max Power was 1182W (12 November)
After air conditioner day, battery bank dropped to below 40%. Each subsequent day the battery bank gained 15% to 20%.
Overall we are very happy with the new system and now have confidence it will suit our desired future camping plans.
A couple issues/bugs we found:
First, 2 of the battery BMS's were set incorrectly by myself (I incorrectly entered total capacity and balancing settings). This caused incorrect readings (from the BMS app) for the first few days and led to inconsistent usage between batteries (some were depleted more than others). Once corrected, all batteries (and battery cells) were synched and within 0.02 volts of each other (cells were within 0.01 volts).
Second, I forgot to synch the shunt when the battery bank was 100%. This provided inaccurate numbers on the GX Touch which made me reference the battery BMS app for actual status. The shunt is now synched.
Advice for others:
you can never have enough panels or batteries. Always plan your system for expansion.
You get what you pay for. Victron just works. Even with my human error, it works.
Spending time up front in the planning process makes for a more pleasant experience. You plan for specific usage so you don't have to stress about using what you want to use, when you want to use it, how you want to use it.
Fantastic report, glad that the system is working as intended. With all the work and process that you went thru it is great to hear that it all is working out as planned. It is a great feeling to not have to rely on shore power and be able to camp where ever you want, and if you are on shore power and it is interrupted there is no worries.
Brian
Brian & Michelle
2018 Reflection 29RS
2022 Chevy 3500HD
acoleman43 I just spent the better part of an your re-reading your thread. I'm preparing to get started on our new Solitude and your information is a great resource.
Jim
Jim and Ginnie
2024 Solitude 310GK - 2020 F350 Dually
GDRV Technical Forum Moderator
GDRV Rally Support Coordinator
I'm planning to do a very similar upgrade to our 21G (although not to that extent, I think...) and starting with two LiTime 230Ah batteries (taking advantage of Cyber Monday sale).
acoleman43 which solar panels (brand) did you end up choosing?
Looking around at brands, wattage, etc it seems like going to 300 or 400 watts makes more sense, unless I'm missing something. Why did you end up choosing the 200 watt panels?
acoleman43 which solar panels (brand) did you end up choosing?
Looking around at brands, wattage, etc it seems like going to 300 or 400 watts makes more sense, unless I'm missing something. Why did you end up choosing the 200 watt panels?
The panels from signature solar are even cheaper than Amazon but you do have to buy 10+ ... anyone interested in a bulk buy?
I went with Newpowa 210W "24v" panels. Newpowa has stopped selling those and now sell 200W panels. I was also looking at Renogy and Rich Solar, but Newpowa had the best size to fit what I wanted and was having a sale when I was looking for panels.
The reason I went with the 200W panels vs 300W was the size of the panels. The original plan was to have 8 panels for 1600W total....but wife didn't want the roof filled with nothing but panels so I compromised to 6 panels for 1200W (technically 1260W). With 300W panels I would be able to fit just 3 of them on the trailer.....maybe for 1200W total - and no room at front and rear of trailer. With 200W panels I can fit 8 with walking room along the sides and to the slide-out. With 6 panels I have walking room along the sides, room where the ladder is and the front is not covered at all.
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