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This is the third iteration I’ve been through using solar to keep our RV’s *chassis* battery charged up when Lance is in storage.
First, there was the inexpensive solution I put together with a few off-the-shelf parts:
Keeping the Chassis Battery Charged with Solar.
THEN, we visited Zamp, and they showed us an even better way to keep our battery charged using a dual charge controller:
An Even Better Way to Charge the RV’s Chassis Battery With Solar.
Shortly after that, we built a carport which covered up all the solar panels on Lance and sent us back to square one. Sigh.
But now, there’s THIS:
Our friends at Zamp reached out to us to see if we’d be interested in testing out some of their newest Obsidian solar panels, and my mind immediately went back to our carport. We had all the panels we need on Lance, but would the Obsidian panels work on a structure? A short while later, here we are.
So the short answer is, yes, of course the Obsidian panels work mounted on a stationary structure. In fact, there were two main things about them that made them a great choice for this application.
First, they’re lightweight. They’re 30% lighter than their regular solar panels. The 100 watt panels you see in this video weigh less than 11 pounds each. That was actually pretty important to me, because our RV carport is a very lightweight aluminum structure. (It’s rigid in the ways it’s intended to be stressed, but like, you couldn’t walk on it, for example.) A heavy panel up there wouldn’t have been a good long-term idea.
Second, they’re low profile and aerodynamic. This was important to me because of – again – the lightweight aluminum structure. I simply couldn’t bolt down something through the roof. The low, aero profile means there will be less wind load on the panel, so it can mount with VHB tape (which was supplied in the kit).
The weather-resistant, can’t-possibly-plug-it-in-the-wrong-way connections were also a nice-to-have, though they weren’t absolutely critical for this application.
Altogether, I got the solar panels up in just a couple hours. And most of that time was simply me messing around on the roof. The actual wiring of the panels to Lance’s auxiliary solar charge port took all of 90 seconds. So far, after a day of obsessively checking solar panel output every half hour, the performance of the panels is about what I expected. The levels have held up to what you see in the video – or better – as long as there’s been sun.
Time will tell if this mounting option (with the tape) holds up to the brutal desert southwest sun. Someone remind me to come back in a year and give an update on the mounting! Seriously… remind me!
James, I have a travel trailer that I have installed a Ring Alarm system in for when it’s in storage. I want to install a solar panel (or 2) to power the unit. This video looks like it could do the job, but I know more would be needed. I’m in the North East so the cold would more than like be a challenge for the battery, but not sure. Perhaps an added Solar generator as well. Just not sure there’s so much content out there. Can you recommend something suitable that could handle keeping the system online.
Well, a lot depends on the battery capacity you have. For 3 out of the 4 seasons, 2 solar panels should be able to keep up with a Ring alarm unit (they don’t use that much power). All you would need to do is leave the battery on, and turn off everything but the Ring. The solar should charge the battery enough during the days to get it through the nights.
Winters will be an issue. Even in St. George Utah, during the winter months, our 2 panels don’t keep up with the various low-level draws on the coach. It still does charge each day, but just not quite as much as it uses up. In the North East, it would be a challenge, and obviously, a panel with snow on it generates zero power. I don’t know what kind of battery you have, but they all work better in moderate temperatures, so you’d also want to keep it warm – which may mean plugging in.
Thanks James for that information it was very helpful. All of the issues you pointed out were my concerns as well.
James, go up and check the mounting! It’s been over a year. 😉
I actually went up there a couple months ago and took down one of the panels temporarily to try it somewhere else.
The mounts stayed put and hung tough when I re-tightened the panels.
Based on that, I’m good.
Thanks for bringing this up!
Wouldn’t an inexpensive battery maintainer do the same job?
You mean something like the Amp-L-Start? Perhaps, but then I’d have to leave the van plugged in and the house battery on all the time. (Not our habit.)
With our dual controller, the starting battery gets its power even if the main battery is turned off.
A very smart idea to put solar roof panels. I wonder if you could not add many more cheaper panels to generate some of your own electricity? Tesla is coming out with a house battery. Eventually, all that high priced home electricity will be a thing of the past.
I like the fact you left your roof intact. No point in having a leaky roof with holes.
The obsidian solar panel though is $499 which is 500% higher than silicon, with no verifiable benefits, apart from its sleek aluminum frame. I would not buy something so pricey myself unless free for a demo. Obsidian is a cheap volcanic glass. Not sure why it should be more expensive than silicon. As far as sexiness goes, I’m not wearing it like an obsidian gemstone and it sits where it will never be seen, so could look as ugly as a shrunken mummified head but who cares. I have not been able to find any advantages that obsidian delivers over silicon.
However, James, it is always a pleasure to see new products and watch your videos and in-depth analysis. You research everything with zeal, tenacity, and passion and this is rare and very much appreciated!
Stephanie – great camera work and angles. Clear, sharp, good light, well documented. Your work is invaluable to the video, many thanks!! You are mostly silent and in the background but your presence is felt.
Looks to me you are on the north side of your house, depending on the time of day at the end of your video. Why not just tip the panels against that sunny wall, mounted to 2X4s, facing the sun.
Too late now…
PS. Note to self. Disconnect BEFORE driving away.
Where the panels are mounted now, they’re not visible from anywhere a normal person would stand, and they get sun for most of the day. I’m good with it.
We had a (less sexy) solar panel on our last RV carport – disconnecting is part of my routine.
Hi James, I was going to mention how grossly overpriced Zamp panels are, but then I saw that you got them for free. Free is a good price, However, most people will have to pay $500 each for those panels. $500 would buy you a pretty good 300 watt system with an MPPT controller. I do have a quibble with the overpriced Zamp PWM solar charge controller. You are throwing away 20-30% of your solar output by using that controller. You really should upgrade to MPPT controllers or at least one MPPT controller for the house batteries and a cheap $20 PWM controller for the start battery.
As far as the weight goes, I think an additional 6-7 pounds would not have impacted your roof all that much. Personally I would have through bolted the panels with suitable backing plates to spread the load over a much larger area of the corrugated aluminum roof. Alternatively bolt the panels to pieces of aluminum plate and tape those to the roof with a much larger contact area for the tape. That would both decrease the point loads on the roof and give you a much larger overall bond strength.
Hey Todd –
As far as charging our house battery – it’s lithium and huge. Solar helps on our rig, sure. But it isn’t going to make or break things for us when we’re on the road. That’s entirely determined by our alternators. (Solar in storage is a different matter, and I’ll get to that.)
While a MPPT controller might provide a bit more power on the road – it still wouldn’t matter when compared to the size of our battery and alternators. We proved this out in this video. So, instead of filling a swimming pool with an 8 oz coffee cup, I’d be filling it with a 10 oz coffee cup. I mean, yeah, it’ll go 25% faster, but who’s going to wait around for that?
Now, in storage, I’m not using much power at all. The PWM controller provides well more than all the power I need for both the house and chassis batteries. Upgrading to an MPPT controller would provide yet more power that I wouldn’t need or use. It’s like saying “25% more accordions!” Uhhh… no thanks.
As far as the mounting – our RV carport came with a warranty that I don’t want to invalidate.
I contacted the company about mounting the solar panels, and was specifically advised *not* to drill holes through the corrugated portion of the roof. Tape was fine, and was the recommended approach.
I suppose I could have tried a larger piece of aluminum for more tape area, as you suggest. But that seems like overkill, and just making more work and expense.
If you could have felt how hard I was torquing on those mounting feet, just held down by the tape… you wouldn’t be worried either.
I wonder if those panels would stay in place on top of a car
With just using the sticky tape?
What do you think?
Love your channel
Hope you and your wife stay safe
I would love to use them like that and plug them into a jackery or another one like it
DON’T quote me on this, I don’t want to be responsible if it fails, but I think the tape would work if you installed with the right kind of VHB tape.
I know they install to some RVs this way, so I think it might be OK.
Hello James, Great idea putting panels on top of the car port to charge Lance’s batteries. It looked like the hardware provided was stainless steel, if so, this another long term plus.
I can’t say for certain what the metal of the brackets was. I know the panel frames are made of aluminum extrusions. They have some aluminum forming abilities at Zamp, so the brackets might be anodized aluminum or something like that.
The bolts very well might be stainless.