Solar Suitcase & OEM system?

[Roly]

Hi Chin,
The ability to tilt the things was just a byproduct of the final design. I have not ever bothered to tilt in use, too much work; but could some day if sitting for a while in a East/West orientation, tilting the panels to the South. It would require a couple of struts to hold 'them up.

If I added a couple more panels, which the controller can handle, I'd make them portable with a length of PV cable and some sort of connector/receptacle. Those panels could be deployed to catch max sunlight. Where to stash them underway, however, I don't know.

I ripped out the LVD and the battery isolation unit on the left front fender.

Roly

[Blue~Go]

Full disclosure: I *still* haven't mounted my roof panels (ground panels are just effective enough to make me lazy). But that said, my buddy who changes RV's semi-annually at first had a Class C with six tiltable panels on the roof, and no ground panels. If he wanted to tilt them (necessary in winter due to low sun angle), he had to first consider how to park with that in mind (since they only tilt either to one side or the other), then climb up there and tilt them, then go back up and un-tilt before driving. Okay, that's not the hardest thing in the world, but it's a bit of a pain sometimes.

So for his next RV (which also didn't have a very good roof for climbing on), I was in on the install and we put the same six 100-watt panels on the roof, but purposely didn't mount them with the intent of tilting (they are still on two part mounts so they CAN be tilted, but it wasn't part of the normal plan - still handy for mounting and etc. though).

Then he added two 100-watt ground panels. With the 600 on the roof (flat) and the two ground panels perfectly aimed and tilted (no matter how he parked), it seemed to do just as well as his previous setup. An additional advantage is that in summer, the two ground panels would help if there was a nice shady spot (or partial shade) because they could be put out in the sun.

The downside is you have to have a place to put the ground panels when driving. In his case it was no problem. For me with the Chinook it's not quite as obvious, but I have managed. What I do is if I'm towing the car, they can go in there. If I'm on a sporty trip with just the Chinook they fit pretty well standing up behind the driver's seat (wedged between the seat back and the forward end of couch). They fit even better when I had the "flexible" type panels, but I have found they just don't hold up very well so I changed to aluminum/glass panels. I do give the panels a quick wipe with a damp towel before bringing them in, along with the 35' connector cord (that goes in the built in hatch area where the shore power cord also goes).

Just another option for having angled panels.

BG

[Blue~Go]

Roly,

Since I see you brought up additional panels in the form of "ground" panels (while I was typing the above), here is one more consideration (for anyone doing it).

With ground panels, there is basically no reason not to have them in series. All the advantages of series apply, and none of the downsides (basically shade on only one panel, but it's easy to keep that from happening).

The biggest upside is that you can have a longer/thinner cable leading from the panels to the rig. This is a huge plus. (You can do the same thing with one, higher-voltage panel, but that gets unwieldy) (Or you could have just one single panel, but then you are back to low voltage, however with lower amps so wire size still not unmanageable).

So the consideration then is how (or if) to integrate the ground panel(s) with the solar controller you have for the roof panels. If the controller is of a suitable amp rating, and you have your roof panels in parallel, and a single ground panel is within a volt or so on the Vmp rating, then you can just tack it on.

If the roof panels are in parallel (and they are ~18 volt panels), then if you put a pair of ground panels in series they are at around 36 volts and you can't add them to the one roof controller.

If the roof panels are in series (so about 36 volts) and the ground panels will be the same, you can add them to the controller.

If you don't end up with a match, you can run two controllers. In fact that is becoming popular anyway due to the fact that often multiple panels are not in the same conditions anyway, so multiple controllers can "set themselves" up for the best Vmp.

Anyway, I just mention it so that if a person *does* want to use just one controller, they can plan ahead to have the voltages match (and of course appropriately sized controller amp wise).

[danesk]

Since a parallel connection would provide more amperage, I believe that is the best way to go...?

If you use an MPPT solar controller, you can wire your 2 panels in series. The result is higher voltage which equates to less loss for a given run and wire gauge.

Thank you Scott for the explanation of series connection. I went ahead and wired my two panels in series.

[deppstein]

You all are WAY ahead of me on solar. I don't have anything on the roof (up until the relatively recent purchase of my Alpacka Rafts, that real estate was reserved for hauling canoe or kayaks), and only carry a 200 watt solar suitcase for ground deployment. So, the only contribution I can make to this thread pertains to storing a solar suitcase while underway (other than Blue's suggestion of in a Towed, or behind the driver's seat). My Zamp 200 Solar Suitcase came with its own case (which I have "Scotchguarded" for additional water proofing), and I have mounted it with marine ubolts--ala Blue's suggestion-- to sit on the back bumper in front of the Continental Spare. As you can see in the attached pics, I can still access the outside compartment without taking the suitcase off by just loosening the holding straps to let the panels tilt back out of the way. Works well for me.
David

[danesk]

Warning, wall of text! But I'm too hungry to add emoticons. Must. Make. Supper!
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It would be better if you could get the controller a bit closer to the batteries, but that's still better than on the other side where the original one was.
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I like to shoot for less than 2% voltage drop, and less than that is even better.
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Some people may (rightly) point out that these figures are for max panel output and so with lesser output you could use smaller wire for same voltage drop. That's true, but solar is such a relatively weak power source, and we only have room for so many panels on the roof -- so my feeling is I don't want to lose any of the potential. I've wired up for under 2% voltage drop at max output and have never been sorry I did.
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I have removed the pillars (thanks to A Rooney's tips no-one is still trapped in there ).
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Also, you are going to want to drill new hole(s) to get the wire to your outside batteries, and a good spot for that is behind the pillar (stock wires do that from the LVD).
I think you'd want to drill new hole(s) into the battery compartment wall vs. cramming the wires in an existing hole.
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BG

Blue-Go,

Again, thank you for the very thorough discussion! This helped immensely with my installation - now just waiting for the gland to arrive to finish up.

After my last message I found your previous thread outlining the process of removing the pillar...that was indeed a challenge, but I can't see how new wires could be run without doing so. I ended up drilling two holes in the floor, behind the pillar, for the 10 ga. wires. One of the two holes in the battery compartment had plenty of room for these wires, so I did not need a new hole there.

My charge controller from Renogy seems very adequate, programmable to set voltage boost, absorption and float values...equalization values also, but Windy Nation says do not use equalization for these AGM batteries. I will program the controller to Windy Nation recommendations.

The controller did arrive with a temperature sensing unit, but I did not install it...would have had to drill another hole in the floor and try to route the very thin wire. Not sure if this is necessary if I'm not allowing a high voltage equalization charge, but will research this more. Worse case scenario is removing that pillar etc. and trying to fish the delicate connector through.

The rest of the installation went well, with both panels on the driver's side. Looking forward to having an abundance of power for our very frugal needs (led lighting, occasional heater fan, perhaps cooling fan, fridge).

Thanks again for your time and very awesome advice. Your commitment to sharing knowledge is much appreciated and a great example for all.

[Scott]

Hey good stuff! I enjoy reading about the various approaches.

For us (me), there seem to be enough chores in life as it is. So setting up camp is limited to chocking the tires and grabbing a chair, and that's about it. Plus as mentioned, everything you set up, you have to break down. I try to minimize that as much as possible.

So with that philosophy, fixed roof panels suit me best. Apart from occasional cleaning, they're completely passive, plus no storage concerns. If I find a completely shaded spot, I'm fine for three days, even with old batteries.

I'm going to redo some things, namely upgrade to an MPPT series scheme and make the terminal connections more corrosion proof.

Fun stuff. Even just a "decent" solar setup in an RV is very, very nice.

[chin_k]

I ripped out the LVD and the battery isolation unit on the left front fender.

Your new setup with the BS 7622 and MPPT is very similar to one of my plans. However, I have not order all the components and get to it Too busy with other projects. I assume the temperature sensor is not integrated into the solar controller? Without the LVD, you are using the solar controller for turning the load on/off, and relies on it for disconnect when voltage is too low. The one thing I do like about the old LVD is that it lets you override the disconnect, and I don't know if any SC can do that. If someone come out with a MPPT solar controller for two separate batteries (coach and start), with temperature compensation, and load on/off, I will jump on it right away, but so far, I have not see one.

[Scott]

Without the LVD, you are using the solar controller for turning the load on/off, and relies on it for disconnect when voltage is too low. If someone come out with a MPPT solar controller for two separate batteries (coach and start), with temperature compensation, and load on/off, I will jump on it right away, but so far, I have not see one.

Can your disconnect be a simple switch? Or do you want it automatic? I like switchable manual breakers. Dual functionality.

For two separate batteries, or banks, just use separate controllers? Take in the free energy and distribute as necessary.

But if it's for the crank battery, personally I wouldn't bother. In motion, it's the alternator. Stationary, it's a battery tender.

[Scott]

I'm curious if roof mounted panels increase or reduce heat gain in the coach?

They're reflective and spaced up from the roof a couple inches. So that would sound good. But ... they're black and they get hot. Quite hot. Plus they have some mass, so they take a while to cool off in the evening. I'm stumped on this one.

If I remember to check while the sun is squarely overhead in August, I suppose I can take temperature readings of the ceiling under the panels and under the side without panels.

Unless anyone already knows?