Solar Questions

[richp]

Hi,

I presently have 300 watts flat mounted on the roof of my Silverback, with two T-105 batteries. I didn't get quite the performance I was hoping for last winter in Quartzite, although admittedly I am heavy on night time TV and other 120 volt use.

I just acquired two more 150 watt Renogy panels at an excellent price, and am thinking about using them in ground operation, rather than putting them on the roof. Which brings me to a few questions...

1. What type of electrical fittings do people typically use to easily and quickly connect/disconnect comparable wattage ground panels? I can come through the trailer sidewall and be within 24" of the controller. But I need a high wattage capable, waterproof connector to get there.

2. Can anyone share pictures of tiltable ground frames they are using for relatively large panels (mine are 39"x39"), so I can scope out how to deploy mine?

3. Considering theft vulnerability of this kind of setup, how are people securing their panels?

Thanks for your help.

Rich Phillips

[N6ZCM]

Hello Rich...

Others have come up with some very clever ways to mount on the roof and angle the panels to the sun!

Without adding some very heavy hardware to mount to the ground and angle... and keep from being stolen would be very hard. Of course the more secure it is will only keep the honest man honest... if they want it they will figure out a way!

Which takes me back to installing on the roof. I personally would do the roof way! Just seems like a much easier and secure way to do it, PLUS stopping somewhere for one day all of your panels are at least charging a little!

Panels laying flat on a roof, can only produce it's highest output during the Summer in the Southern states! Sun directly overhead!

Here are some pics from Google... solar panels on roof of RV.
it will give you a lot of ideas!

Plus the more panels on the roof the cooler your rig will be... i.e. shading the roof!

[richp]

Hi N6ZCM,

Thanks for the prompt reply. I realize the benefits of tiltable panels on the roof, and think a lot about the theft issues.

But I'm 70 years old, and just not inclined to commit to a system that requires me to clamber around on the roof of my fiver. I'd sooner just mount them flat and try to live with 600 less-than-optimal watts.

Additional thoughts, anyone?

Rich

[aeblank]

Is your problem solar capacity or battery capacity? Night time usage is obviously battery usage. Did they get charged back up, or not?

I agree with roof mounting. Even if less efficient, add more to overcome that... IMO...

[N6ZCM]

Originally Posted by richp

Hi N6ZCM,

Thanks for the prompt reply. I realize the benefits of tiltable panels on the roof, and think a lot about the theft issues.

But I'm 70 years old, and just not inclined to commit to a system that requires me to clamber around on the roof of my fiver. I'd sooner just mount them flat and try to live with 600 less-than-optimal watts.

Additional thoughts, anyone?

Rich

Hey Rich
I am not allowed on the roof by myself(wife's rule) and I am getting too old for that crap.
Here is another thought.. Create a stand in the back of truck that can be folded down and stored when moving, this would add some security!

Another create a foldable stand and chain to the 5th wheel, but that entails some muscle tearing down and setting up.

The other thing I do is run the genny at the same time as max output of the panels for about an hour then the panels keep it topped off until night for watching TV!

Or like this guy... get a pitbull and chain him to the solar panel

[richp]

Hi aeblank,

I dropped my batteries as much as 35-40 percent many evenings in Quartzsite. The pattern that emerged was to run my Honda 2000 a couple of hours in the morning, and then let the sun top them off. This strategy worked most days. So upping the amps into the existing batteries ought to fill the bill.

I also am looking at running the TV and Tivo on a smaller inverter, since my 1000 watt pure sine wave unit is something of a power hog all by itself.

That may help a bit. But my theory is that the panels that fell in my lap so inexpensively last week are a more complete answer.

I just can't resolve the issues raised in my original post, and am hoping to hear about some real world experience with ground use.

Failing that, I'll mount then flat on the roof, with the thought that doubling the wattage will compensate for the inefficiency of flat mounting.

Rich

[aeblank]

Makes sense. What kind of amperage are we talking, anyway? There are some beefy automotive connectors, like a Packard. It's been a few years already, but they have some big terminals with high connection force. Molex probably too.

So, just looked back. 25 amps isn't crazy.

I don't think you need a sealed connector though. Just put it somewhere protected-ish. The 7-way on your truck/camper isn't sealed....

[richp]

Hi aeblank,

Max on this input would be about 17 amps.

My best location is in the sidewall between the battery compartment door and the large access door that exposes the water system and other utility stuff. I was thinking waterproof out of an abundance of caution, I guess.

Rich

[aeblank]

17a shouldn't be hard. I'd guess a 400 series Packard to do it.

If you do it, buy an extra connector and silicone the back half. Connectors aren't sealed when unplugged.

[Skyliner]

I found that for my heavy usage of 70 to 120 amp-hours/day (mostly at night), that 600 watts of panels and 3 pairs of 2 golf cart batteries wired in series worked pretty good and did the job even when laid flat on my roof. Going to 800 watts soon so I have better performance on overcast days.

You can overcome the power gained from a tilt panels by adding a couple of extra panels and never having to climb the roof.

Good luck,
Drew

[Summer2Go]

If you can at least climb a ladder you can still install panels near the edge of the roof. I did most of mine from the ladder. I have been given the "look" when I talk about being on the RV roof. The roof is still the best place.

[richp]

Hi,

I've conceded the battle, and started acquiring the brackets, wire and other stuff needed for a roof installation.

Gonna leave them flat, under the theory that 300 flat watts was sort of close to enough last year, so doubling that -- still flat -- ought to keep me happy.

Thanks for all the input.

Rich

[Schwartzworld]

Originally Posted by richp

Hi,

I've conceded the battle, and started acquiring the brackets, wire and other stuff needed for a roof installation.

Gonna leave them flat, under the theory that 300 flat watts was sort of close to enough last year, so doubling that -- still flat -- ought to keep me happy.

Thanks for all the input.

Rich

I'm researching solar for next year. I realized that tilt was important but I don't carry a ladder and the ladder on the back of my RV isn't going to hold me.

I then found this piece of hardware, a linear actuator. You have to search for a waterproof version, they are out there. Combined with a remote control I can raise and lower my panels from the ground.


https://www.amazon.com/Linear-Motion...node=350654011

[richp]

Hi Schwartzworld,

Hmm, got me thinking.

Do you have a link to something that shows how one of these would be rigged, in terms of the angles of attachment? In my admittedly simple mind, I don't see how one of these would take a 39"x 39" panel like mine from flat to 45 degrees without a fair amount of intermediate hardware and linkages.

Also, I'm wondering how the panel would be snugged down firmly enough for travel without vibration, which could damage the panel.

But I sure like the concept...

Thanks.

Rich

[Schwartzworld]

Originally Posted by richp

Hi Schwartzworld,

Hmm, got me thinking.

Do you have a link to something that shows how one of these would be rigged, in terms of the angles of attachment? In my admittedly simple mind, I don't see how one of these would take a 39"x 39" panel like mine from flat to 45 degrees without a fair amount of intermediate hardware and linkages.

Also, I'm wondering how the panel would be snugged down firmly enough for travel without vibration, which could damage the panel.

But I sure like the concept...

Thanks.

Rich

This is where I got the idea, just need to beef it up and expand it a bit for bigger panels. I would use the same basic design except for the rod going all the way through the panel. I'd use some kind of end hinge. I'd mount the actuator on an aluminium rectangle beam.

https://www.youtube.com/watch?v=Kk2sufRnE8E

[richp]

Hi,

That helps a lot.

Still doesn't give me ideas for a solution to the "bouncing and shaking going down the road" problem. But yeah, he had a pretty simple setup that seemed to work pretty well on a panel that size.

Thanks.

Rich

[joeuncool]

I am willing to bet a large part of your issues are battery capacity. If you are a heavy night time user as you said, I wouldn't expect 2 T-105 batteries to give you more than 3? hours of heavy use. Running a 5ver you should have the room to put 2 more batteries in there. If you have the weight capacity and you spend most of your time dry camping off batteries I would figure out if you can handle the weight of 6. Bigger is better, cue Tim Taylor. I am looking to be a heavy battery user with an inverter but first I am either going 3 12 volt batteries or 4 6 volts. Still doing the weight math in my head and how much I want to deal with.

If you are getting direct sun on 350 watts of solar, that should be enough to fully charge your 2 batteries every day and more than enough to charge 4 batteries in a full day. If your 350 watts are not charging the 2 batteries in a full day, check to see what kind of output you are getting to and from the controller. There might be some issues.

I have 2 T-105 batteries and 200 watts of solar. I was able to get them from 70% back up to full in a couple hours of good direct sun. But mine are portable aimed directly at the sun.

As for security, I have 25 ft of chain that I lock my panels to the trailer with. Gives me length to move them around while still locked up. Yes somebody with a bolt cutter can run off with them but hey, forces the thief to have the right tools.

[aeblank]

It should pull it down onto some stops somehow, for the vibration. What are the dimensions of the panels you guys are using? If I get bored, perhaps I can do a mock-up. Perhaps a little self serving, as well.

Of course, which way to tip? What if it tips the wrong direction? Or does it swivel (way more complicated)?

I haven't watched the video yet though, if some of that is answered.....

[Schwartzworld]

Originally Posted by richp

Hi,

That helps a lot.

Still doesn't give me ideas for a solution to the "bouncing and shaking going down the road" problem. But yeah, he had a pretty simple setup that seemed to work pretty well on a panel that size.

Thanks.

Rich

Here's a very over priced tilting solar panel mount that I can make from angle aluminium at Lowes. Eliminate the vertical part that holds it in place. I would add a T shaped rectangle beam between the legs to mount the actuator and add a pivot point for the arms that raise and lower the panels.

https://bestsale.com.au/solar-panel-mounting-bracket---adjustable-angle---suit-panels-up-to-555mm-
wide.php

[richp]

Hi aeblank,

I'm adding two 150 watt Renogy panels that are 39"x39".

In my head, I have a hard time accepting that a couple of gravity stops would be an adequate protection from the road vibration and jolts that would assault something that big going down the road at 60-65 mph. Maybe it's my current confidence level in the six HD brackets that are holding each of my other two 150 watt panels, and making a mental comparison with the robustness of a motorized tilter and non-positive lockdown.

Unless I get up on the roof and somehow positively lock them down, in which case I might as well ditch the motor and tilt them manually...

Nah, I think I'm still committed to flat mounting the new ones. But I'm real interested in what others work out and how it works for them.

FWiW.

Rich