The solar installation went pretty smoothly. My main components were two Renogy 50-watt mono-crystalline panels, a Victron MPPT charge controller, and a couple of 15-amp circuit breaker switches. I installed the controller and switches inside a drawer cabinet to be out of sight, yet accessible.
I ran the battery positive lead to the always-hot terminal of the battery cut-off switch located low by the entry door. That will provide charging whether the cut-off is on or off. The components are next to the refrigerator, which made for an easy way to route the cable from the panels through the vent stack behind the refrigerator without having to drill holes through the roof.
The two panels were attached just forward of the A/C unit and near the fridge vent to minimize the length of cable run, and in some unused roof space. The brackets are screwed to the roof as well as glued with marine-grade poly adhesive.
On previous RV's, I had a 60-watt panel for two batteries and a 30-watt panel for one battery. My main objective was to keep the batteries charged through long storage periods, and provide some extra recovery charging for camping without hookups, and those served my needs well. The Orion has two batteries, so I decided on a bit more power (100 watts total). We don't boondock enough to require several hundred watts of power, and budget also was a factor. The panels are wired in series to provide 37 volts nominal output while keeping the amps the same so the feed wires don't need to be heavier gauge. Victron recommends the higher voltage setup for better efficiency.
This particular controller has Bluetooth connectivity with an app that Victron provides for smart phones. After I started the system and got the app synced with the controller, there were immediately two firmware updates that installed automatically. When those completed, I got status readings on my phone. This was morning, and the app showed 56 watts output along with charge parameters to the battery. Later near noon, I saw 84 watts output.
I believe this setup will keep the batteries in good shape. There are four modes of charging including equalize, which can be configured to be off or repeat as desired. Other parameters can also be set via the app. I am very happy with the outcome and performance so far. No more significant projects contemplated--time to go traveling and camping.
Hi Bob- Once again, nice work! What was your thinking getting Renogy vs WindyNation, two 50 watt panels vs one (or two) 100 watt, and MPPT vs PWM controller? You're a well thought out and thrifty guy so your choices intrigue me. Monocrystalline panels and MPPT are both more expensive, you've got plenty of room up there on the roof for the bigger size of polycrystalline, and with your stated usage and goals I personally would have picked PWM. Thanks, Gary
ReplyDeleteI had used Renogy panels before. Other brands may be comparable. I thought, perhaps incorrectly, that mono panels are slightly more efficient in lower light conditions. The cost differential wasn't that much. I went for the most efficiency and performance in this system. For the same reason that power companies step up the voltage to transmit electricity over long distances, I wanted the double voltage output of two panels in series. I was able to use 12 ga wire since the amps were still low. PWM controllers can only accept single panel voltage (about 36v max.). MPPT controllers can handle over 70v and convert the input to 12v output more efficiently (Victron claims 30% more than PWM). So I figure my setup is equivalent to a 120-130 watt poly/PWM system. I liked this particular Victron controller for the Bluetooth connection to provide status on my phone app. I didn't have to buy or install a separate display unit. I also like the ability to configure some of the settings like equalization cycle for battery life. That's my story, and I'm sticking to it.
ReplyDeleteThanks! Did you get it all on Amazon? I had a WindyNation 100 watt "kit" in my sights for $160 on Amazon but now you've got me scratching my head. I got my schooling on solar here: https://www.thefitrv.com/rv-tips/how-much-solar-do-i-need-on-my-rv/ . I found it a very, very informative piece and recommend it if you haven't seen it before.
ReplyDeleteLike James on thefitrv, I went from experience on my solar needs. We had a big class A with two group 27 batteries and 60 watts of solar with PWM controller. That unit would drain the batteries in a day of dry camping. We spent 5 days and nights in Glacier park with no hookups. With just the solar and running the generator every morning for a half hour while grinding and brewing coffee, the batteries were happy the whole time. Again, I'm mainly interested in keeping the batteries charged during storage, with some benefit for a night or two of dry camping. And, we still have a generator. If you do more boondocking, size up accordingly. X watts = X watts for poly or mono; get what you like. I had a Kyocera 60w panel and a 30w Renogy (on a class B), both poly, and they worked fine. I did get all my components on Amazon except the panels, which I ordered directly from Renogy which, at the time, actually had the better price. Good luck on your project. Thanks for looking at my blog.
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