Man, there's a lot to read and digest with possibly installing a small solar panel. I very recently replaced my original 1-stage converter/charger with the Progressive Dynamics PD4600 series converter/charger. Is a single solar panel (80W) connected to the PD converter/charger or directly to the battery? Opinions on roof mounted or portable? Thanks for helping me start the search!

You will need a solar charging controller. If you have room for the panel on top it is less hassle than a portable you have to set up each time.

Nice upgrade.You don't convert the solar panel directly to anything. You are going to need an MPPT solar charge controller to go between the panel and the battery.Also, you connect the solar directly to the battery because you want to be able to make power from the sun whenever you can, regardless of other conditions (truck running, shore power, genset, etc)

You will need a charge controller between the panel and the batteries but it does not have to be MPPT unless you choose a solar module that is nominally 24 volts. All 12 volt nominal modules can be controlled with a PWM charge controller which is less expensive. Read here: Jack and Dan Meyer's Golden Rules

I found one 80w panel to have too small an output (5.1amps at high noon)but that a 120w panel with more like 7.5a would do much better. YMMV I suspect if you got the 80 you will soon be mad at yourself and wish you had gone bigger.Although, you can get two 80s and hinge them for a "suitcase fold-out" portable and have 160w (but now you will need a 15a controller, not a 10--RJ says they are now $15 so that's ok. :)The thing is that the 120w panel is not much bigger or heavier than the 80 so it is no more trouble to deal with if using it as a portable. Not much more in price either. In addition a simple PWM 10a controller will run the 120, and they cost under $20 (ask RJ where he is getting his controller collection from--great prices)A portable gets you the most haul during the day since you can keep pointing it to the sun. You could try it as a portable first and if that is found to be too much bother, then you can nail it to the roof (but now you need to install it--no labour costs when using it as a portable)The panel can be stored behind your sofa or on the bed when travelling, or whatever works.The controller should be close to the batteries and it has one set of wires going to the battery and the other set going to the panel. The controller's wires to the battery should be in parallel with the converter's. Both can charge at the same time. But don't have the converter upstream of the controller so it tries to charge through the controller to get at the battery. You can buy proper wiring of any length required; I use standard battery booster cables I already own to connect the portable panel to the controller, which has fixed wires to the batteries, but how you do that depends on the layout of your RV.Lots of ways to do it.

OP here - Thank you! That was really helpful. So, I'm figuring out that I do not have to buy a "kit" and that it might work better for me to buy parts independently? What about a "mount" to change the angle. I have not seen that type of thing during my day's Googling. I think I have worn off my fingerprints! BFL13 wrote:I found one 80w panel to have too small an output (5.1amps at high noon)but that a 120w panel with more like 7.5a would do much better. YMMV I suspect if you got the 80 you will soon be mad at yourself and wish you had gone bigger.Although, you can get two 80s and hinge them for a "suitcase fold-out" portable and have 160w (but now you will need a 15a controller, not a 10--RJ says they are now $15 so that's ok. :)The thing is that the 120w panel is not much bigger or heavier than the 80 so it is no more trouble to deal with if using it as a portable. Not much more in price either. In addition a simple PWM 10a controller will run the 120, and they cost under $20 (ask RJ where he is getting his controller collection from--great prices)A portable gets you the most haul during the day since you can keep pointing it to the sun. You could try it as a portable first and if that is found to be too much bother, then you can nail it to the roof (but now you need to install it--no labour costs when using it as a portable)The panel can be stored behind your sofa or on the bed when travelling, or whatever works.The controller should be close to the batteries and it has one set of wires going to the battery and the other set going to the panel. The controller's wires to the battery should be in parallel with the converter's. Both can charge at the same time. But don't have the converter upstream of the controller so it tries to charge through the controller to get at the battery. You can buy proper wiring of any length required; I use standard battery booster cables I already own to connect the portable panel to the controller, which has fixed wires to the batteries, but how you do that depends on the layout of your RV.Lots of ways to do it.

Just Starting Solar Research | Good Sam Community

132 Replies

red31
Explorer
Aug 11, 2013
Mitch, I just hooked up mine with the controller laying on the garage floor and the panel propped on a tree outside.

I plan to mount the controller to a 1x6 and secure the wires to the board near the controller so the stain is not at the controller. This board will be wedged/placed/secured near the battery.

With everything disconnected I'll store the 1x6 and wires and the panel for transit. At home or camping, the board gets placed, clips to battery, MC4 to panel and panel placed in the sun. A more permanent install for the controller may be in the future but the panel 'sees' no sun in the garage.
Almot
Explorer III
Aug 11, 2013
mitch5252 wrote:

I'm having trouble imagining the wires going into the controller and not breaking in a short period of time.

In my mind, I am picturing disconnecting the panel from the panel, and disconnecting the battery from the battery, which would leave the 4 wires on the controller. Now, if I coil up those wires to stow away, won't that put undue pressure on the connections and shorten their connection life pretty quickly?

This is why I don't like portables. Yes, you should take a reasonable care not to bend them too much next to the controller body.

For panel/controller cables you can make a "quick disconnect" - cables with MC4 connectors permanently attached to controller, and cables with same MC4 connectors that you already have on the panel.

mitch5252 wrote:

I have to be able to see the controller on a pretty regular basis, right?
A couple times a day is more than enough. Put controller in storage space - permanently. Bolt it to the floor or whatever. Pass the wires under the almost-closed lid when charging, and move them in when not, in a loose bundle. This will take care of stowing/twisting/breaking cables when taking controller in and out. I wrote this already.

Edit - PS: I just saw that you have come to the same solution, in your post with photo. Well - sometimes message has to be repeated...

Polarity of the cables - it doesn't matter what color you use, as long as you don't confuse + and -.
Where did you get those blue and black wires that you say are "from the battery"? If you are using booster cables with crocodiles, they are - almost always - black and red. In trailer wiring there can be black, white and red, there no consistency, but I don't think manufacturers use blue.
pianotuna
Nomad III
Aug 11, 2013
Hi Mitch,

Yes! That's the right attitude. This IS fun.

2 pole connector

You could even make it "goof proof" by using a different type of two pin for the battery and another style for the panel connection. (I would)

Buccaneer two pin
BFL13
Explorer II
Aug 11, 2013
Yet another way is to put a "cable hatch" into the cargo bay door. I did that and it has worked well. The cable hatch is at any RV parts store for under $20. Has a snap lid with a sliding closure in that. This lets you pass wires through it from outside and then close and lock the cargo bay door like normal. It can be shut for going down the road so road stuff and rain can't get in.

No mice got in yet either.
xzyHollyxyz
Explorer
Aug 11, 2013
If I don't disconnect from the battery, then the wires will be sticking out of my storage compartment, unless I find the cajones to drill a hole in the storage compartment floor! :)

I'm going to Google image search a 2-pin connector...........

Okay, I get it. Now, do they make those things in "sizes" so the 12 gauge wire will fit?

Dang, now that I'm not discouraged, this is getting exciting! And fun.

pianotuna wrote:
Hi Mitch,

There is no need to disconnect the controller from the battery bank. You could have a switch (I do).

So you will only need two clips (may I suggest insulated ones?) But it seems to me a two pin connector would be even better than clips. (such as the four pin connectors for a trailer?)
C_Schomer
Explorer
Aug 11, 2013
Agreed, there's a lot to understand. I got a system from AM Solar in January. 1 - 150w poly crystalline panel, mppt controller and 32' wire kit for ~$400. I would have needed about three times that much if I would have believed all the on-line solar calculator worksheets. I use a bipap and we ran the furnace at night and my batteries were fully charged at the end of each afternoon even tho it was partly cloudy and the panel (mounted to the luggage rack) was angled to the north a little. I'm happy like a fly on spit... It made me feel like I actually knew what I was doing! Craig
pianotuna
Nomad III
Aug 11, 2013
Hi Mitch,

There is no need to disconnect the controller from the battery bank. You could have a switch (I do).

So you will only need two clips (may I suggest insulated ones?) But it seems to me a two pin connector would be even better than clips. (similar to the four pin connectors for a trailer?)

There are water proof connection boxes you could use as well.
xzyHollyxyz
Explorer
Aug 11, 2013
I think it's coming together in my head...

Mount the controller on a thin sheet of plywood and fasten that somewhere around where the yellow arrow is:

Then make 4 leaders maybe 18" long that terminate with an alligator clip. When it's time to "deploy" the system, open the compartment and clamp the 4 clips to the other wires and voila - battery charging!

How's that sound?

A second scenario forming in my mind is drill a hole in the bottom of that compartment to the outside and fit it with some sort of waterproof closure? Then, when time to deploy, the 4 leaders could go through the hole to the outside and be hooked up there. That way, compartment would not have to remain open and unlocked.

Any suggestions to a waterproof closure - kind of like an outdoor electric outlet thing... ?
pianotuna
Nomad III
Aug 11, 2013
Hi,

If you can fry an egg, and turn a screw driver you can install a solar system.

mitch5252 wrote:
pianotuna wrote:
...This is not rocket science.

Might as well be when you've never done anything like this before! :R
xzyHollyxyz
Explorer
Aug 11, 2013
pianotuna wrote:
...This is not rocket science.

Might as well be when you've never done anything like this before! :R

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