Just Starting Solar Research

Almot wrote:
30A controller is overkill for 100W panel. It will leave room for adding another panel though.

Cable panel to controller is probably AWG 10 or AWG 12, either one is fine, length depends on the installation, 20ft may not be enough. Install it, measure, then order cable.

Cable controller to battery - gauge is VERY important, and it depends on the length, which in turn has to be the shortest possible.

Both extension cables (controller to battery and controller to panel) are 12 gauge.

Is that good enough for controller to battery?

Yes, but you can search out less expensive stuff on ebay.

30A controller is overkill for 100W panel. It will leave room for adding another panel though.

Cable panel to controller is probably AWG 10 or AWG 12, either one is fine, length depends on the installation, 20ft may not be enough. Install it, measure, then order cable.

Cable controller to battery - gauge is VERY important, and it depends on the length, which in turn has to be the shortest possible.

Again, thank you for clear and easy for me (somewhat) to understand post!

I plan to order these things:

100W Watt Monocrystalline Solar Panel
Our Price: $169.99

20' Solar Extension Cable with MC4 Female and Male Connectors
Our Price: $22.99

30 Amp PWM Charge Controller (12V 360W max/24V 720W max)
Our Price: $27.99

16' Wire Copper Tray Cable-Connect in between the battery and charge controller
Our Price: $18.99

Does this sound like a reasonable beginning?

Regards,
Michelle

mitch5252 wrote:
OP here again. I think I should have been more specific in describing my situation.

I tow a small (16') travel trailer with a Toyota Sienna van (2006). Weight is an issue (the rig's weight, not mine (although that could be a different discussion in a different category...))

I plan to boondock for several months this coming winter in Mexico (Baja)

I have a Honda EU1000i generator.
I plan to carry a 2-gallon gas can for the generator.

I have a single Group 27 battery and LED lights.
......

My SOLAR GOAL (:@ ) is to cut back on the Honda usage (to save gas due to unknown gas availability in Baja without having to drive many miles) and be able to watch an occasional DVD and charge my iPad.

There is - usually - no problem with gas in Baja. Any place with fresh water will have Pemex gas station not too far. There is a problem with propane, though. Pemex don't sell or refill small tanks.

About your Solar Goal. It sounds like you don't have much roof real estate. Roof-mounted or portable - depends on the length of stay and location. In some places your free-standing panel might disappear after going out to town for a big fiesta, despite being on a camp with some other gringos around. Getting it in and out of the trailer every day, setting up and hooking up can get annoying.

If you decide to go roof-mounted, max up the available space and get at least 2*100. Led lights will need 15 AH a day or less. Ipod or Ipad? Tablet can be more than 15 Ah, depends on daily hours of run and the task. DVD? Played through what - 12" tablet or 36" LED TV? Roughly, all these toys can take 15-30 Ah a day with moderate use. So you are at 30-60 AH a day, roughly. To collect 60 AH with flat panel in winter, you need 400W total panel wattage. Same 60 AH with tilted panel oriented South (not tracking, just tilted South at 40 degrees) will require 200-240W. If you play with toys less, then 300W flat or 150-180W tilted. Or smaller yet - this really depends on your lifestyle. This is what you need to avoid running a generator at all, though you might want to add another Gr27 battery. Having said this, - any panel will cut down on generator time.

Having a tilted roof mount, when you move from one location to another, means - 4 axis tilt, this is too much trouble, IMO. Check the List of completed solar projects - some people have accomplished this (or tried to). There is no off the shelf solution. Same List shows how to flat mount - L-brackets bolted to the panel sides are the most common solution. You drive tapping screws into the roof if it's plywood, or use well nuts if it's fiberglass.

Portable - I don't think this will work well in Baja. Theft is one thing, wind is another. Tie it to step ladder, and it will flip over. Make a heavy frame of 2x2 boards, and it won't be portable.

Have fun.

mitch5252 wrote:
OP HERE...

I think I have found a starter bunch of solar equipment from Renogy. I plan to order one 100W panel and other stuff to try my hand at compiling a working system...hahahaha.

If, in the future, I want to add a second panel, 1) does the manufacturer have to match the original panel, and 2) must the wattage be the same (100W for first panel, therefore, 100W for second panel)? Or can I add, say 150W to my 100W?

Also, I do not want this panel on my trailer's roof. What methods do I have available for placing it on the ground and being able to move it to follow the sun.

You can add any size panel to another in the 12v panel sizes. It is better if their Vocs are fairly close--most are in the 21v range but the watts size doesn't matter. I have paired an 80 and a 130 ok, the 130 and a 120 ok and now have the same 130 and two 100s ok.

Be aware of controller amp size for running these 12v panels. You need the expected max amps of the panel (use its Isc) and allow 20% margin for sometimes getting more. A 130w will gat about 8.2a and it is all proportional so a 100 would get 6.3a eg.

It boils down to a 20a controller will be maxed with 250w of panels and still have that 20% (doesn't have to be exact) Since controllers jump in price as you go up in size, it could be worth getting a 30a controller right off and then no "issues" if you add any panels.

I got caught with my 20a controller good for the 130 plus 120, but then traded the 120 for two 100s so now the single 20a controller was too small. (expected amps 21a with no margin) Rather than get a 30a controller I got a second 20 (much cheaper than a 30 and now use two 20s in parallel. Easier to get a 30 in the first place.

You can prop up your portable panel on the back of a lawn chair and just move it to face the sun whenever you get the urge, or you can use a "dolly" with wheels on it. One thing is you want the bottom a few inches off the ground to clear grass etc that might shade the bottom, so you can use a log to sit it on with a stand behind it to prop it up, or just lean it against the RV. The hard part is stringing the wire from the controller to the panel out there so you have enough wire and don't keep tripping over it.

Locating the portable panel is not that simple either. Your RV makes a big shadow part of the day in over half the day in summer, less than half in winter, especially with the slide and awning out. So you might need to place the panel farther out and not have enough wire. Or else where the panel needs to go is over in the next site from yours or the middle of the campground road! It is all part of the fun picking your parking spot and direction for the RV so the sun gets on the panel with the least amount of work on your part.

OP HERE...

I think I have found a starter bunch of solar equipment from Renogy. I plan to order one 100W panel and other stuff to try my hand at compiling a working system...hahahaha.

If, in the future, I want to add a second panel, 1) does the manufacturer have to match the original panel, and 2) must the wattage be the same (100W for first panel, therefore, 100W for second panel)? Or can I add, say 150W to my 100W?

Also, I do not want this panel on my trailer's roof. What methods do I have available for placing it on the ground and being able to move it to follow the sun.

Listen to BLF !

Get an 80-100 watt panel, one that you can store/haul.
Use it portable at first to see it will do quite well if you move it a couple 3 times a day to track.
If you later decide you want to mount it flat on the roof for less hastle, I would estimate you will need double the watts to get the same amp hrs in a day.

I run a 2 panel portable 190 watt system, and am very happy w/ it so far.
I've purchased everything off ebay, all inexpensive china stuff. Panels were $$130 each, and 15 amp controller for $13, and an identical spare for $15,
and 100 ft of red & blk 10 ga twin lead for $36.

Have fun playin w/ solar. There really is not much to it all,....only if you want it to be.

I've just started using our panel this year and have been seeing what it can do tracking, tilted or flat. I can tell you that a 80w panel is going to have a better chance meeting your needs tracking than just tilted or flat.

while tilted south or flat, the system woke up later and at low amps, then slowly worked it's way to max amps as the sun rose. While tracking the system woke sooner and was close to max once the sun cleared the treeline. Another hour for the haze to burn off and the system produced max amps as long as the sun was out and the need was there.

I agree with getting on the roof and measuring if you plan on mounting it. Find out how much space you have and fill it with the biggest panel possible to fit. You will be drilling four sets of holes per panel, the fewer holes the better.

You have a small trailer, so if it were me, I would get a ladder and see how much space you have, what spots on the roof are less likely to get shaded, and what the dimensions of those spot are.

I'm sure I could get by with 80w in an area that was more sun than shade, but for an extended stay, I'd look for a bit more than 80w, provided that you have roof space.