24 volt solar panel recommendations?

tpi wrote:
Is there any on this list notable for high quality?

Take a look at the most expensive panel on that page. Read the specs. Now go back to the cheapest one. A lot of difference there.

Imagine trying to get a warranty fulfilled by a Chinese company. Unless they have a presence in the US, almost impossible. I don't think solar panel failure is all that common, but I did have a BP panel short out a few years ago. Big burned spot on the back. After 4 years of use (with a 5-year physical warranty), they replaced it in a few days, no questions asked, no charge, no return. This just happened to be around the time of the big gulf oil spill, and I think BP was doing everything possible to be a good citizen.

https://www.solarblvd.com/index.php?cPath=1_270

Is there any on this list notable for high quality?

I don't think he cares about spending a few more bucks if it reliably translates to quality.

RoyB wrote:
It could be the 24VDC Solar Panel DC OUTPUTS work better with SOLAR CONTROLLER but to me the final DC output going to the RV Battery setup should remain at 12VDC so that you can utilize all of the working elements the RV TRAILERS has to use.

They work better with the WIRE from the roof to the controller. Thinner wire can carry lots of volts but not lots of amps.

The OP has indicated the trailer system remains at 12v. If you want a '24v system' however, then you need a DC/DC converter with enough amps to handle the jacks and slides. I have one, and the nice thing about that is I can set the trailer to 12.5v, and it never fluctuates due to battery charging or equalizing.

As for buying stuff on the cheap, I rarely do that because it just doesn't work for me. They have to cut costs somewhere - diodes, weather-proofing, frame.. something.

This summer I intend to run a test of my 24v panel with MPPT to the 12v battery bank, vs the same panel with PWM on the same batteries wired as 24v.

I am suspecting the summer heat on the panel reduces the power enough to put the PWM on 24v ahead in amps to the battery.

Even if the 24v PWM comes out ahead, the problem remains to get 12v to the trailer. Anyway first to see if it is better, then see if it is "worth" solving the 24 to 12 problem.

Good data point thanks...

My pair of 245w panels peaked out at 34a and that was at 10,000 ft and tracking the sun on a cold morning. I don't think he will see much clipping in a flat mount.

Here's the plan:

He has a Blue Sky Solar Boost 3000 rated at 22 amps w/24 volt panels. He's going to wire the panels so at least one of them is switched prior to the controller. In the somewhat rare occurrence of mid day sun when one of the panels exceed 11 amps @12 volts he can switch one panel off for controller protection. It is my opinion the great majority of the time both panels can be operational-due to sun angle or temperature.

FWIW it appears the controller will self limit to the 22 amps. But it is not recommended to use this as a feature-just as a protection. This is both in the documentation and a conversation I had with Blue Sky tech support.

Essentially this is a case of taking advantage of the low price of panels to use in sub optimum conditions-which are more common than not.

This is a weekender with a family who's coming home with too low batteries and not a good way to recharge in storage lot. He has plenty of battery capacity but needs solar to make up deficit once stored, and to keep a bit more ahead of the curve when camped a few days.

It's about density in the module package. A higher voltage module is just combining more solar cells for a higher power output. There's really nothing intrinsically better or worse between 24V nominal and 12 V nominal. The 24V modules are best served by an MPPT controller, though, and the additional expense of MPPT isn't necessary for 12 V nominal modules. For us RV'ers, it's more about what fits on your roof or is more easily handled. I sure wouldn't like to be moving around 24 V modules but I know some do.

Presently, I have one 24V module on the roof. It does a good job with the 300AH of battery I have. In the future I may add another module and more battery capacity. It will be easier to install one 24 V module than two 12 V modules and the associated wiring.

At least from my limited knowledge, the 24 volt panels work for my friend on his bus.

1. The physical size works for him. Works with what is already on the roof.

2. Running at a higher voltage it appears from the controller documentation that the wiring sizes can be smaller. Wiring from panels to controller-which translates voltage to what is appropriate to batteries.

3. Cheaper per watt.

Thanks for the input. Ordered the panels.

I guess I question to know why a 24-volt solar system is good for RV applications..

We all know solar panels do not work standalone and the sun energy has to be stored in batteries for us to use them in our RV trailers.

It is easy of course to series a couple of 12VDC batteries but the resulting 24VDC is not really a good component IMO to use in the RV World... 24VOLTS DC is too much power to charge a 12VDC Battery system. I never see anything higher than 14.4VDC here with my setup but I do hear some RV Battery Systems will work with 15VDC charge voltages.

It could be the 24VDC Solar Panel DC OUTPUTS work better with SOLAR CONTROLLER but to me the final DC output going to the RV Battery setup should remain at 12VDC so that you can utilize all of the working elements the RV TRAILERS has to use.

To me this is maybe something one would do at a Residential Facility, not a mobile RV trailer setup...

I understand a higher DC VOLTAGE will make make power better but it just flies against what we RV TRAILER types have to work with.

To me it would just add to the problems to make a 24 VOLT DC compatible with the 12VDC BATTERY Systems the RV trailer have???

Being new to all of this I am probably out in left field somewhere we these comments...

Just reading and learning for my next project of adding SOLAR PANELS to my trailer....

Roy Ken