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

xzyHollyxyz
Explorer
Aug 11, 2013
mena661 wrote:
Yeah you could afford to use more lights if needed.

Most likely won't need to use the lights more - after dark, I'll be in the Cantinas, dancing to the rhythmic beat of "La Cucaracha"

Aw, just kidding...
mena661
Explorer
Aug 11, 2013
Yeah you could afford to use more lights if needed.
pianotuna
Nomad III
Aug 11, 2013
Hi Mitch,

Earlier you posted 2.16 watts for the led's. At twelve volts that works out to about 0.18 amps. I guess you could use them for a lot more hours? LOL!

Based on the audit running the genny every second day for say 3 hours should work well. Or get a bit more solar ( a second 100 watt panel)--and never run it again, except for exercise or the air conditioner.

But--try it out first. You can always add more capacity later.
xzyHollyxyz
Explorer
Aug 11, 2013
Here is my Energy Audit (with the math done correcty this time...I forgot to switch watts to amps..thank you, Tuna)
pianotuna
Nomad III
Aug 11, 2013
Hi Mitch,

I would not go smaller in size. In spite of everything everyone says, "size really does matter".
Rbertalotto
Explorer
Aug 11, 2013
On your last paragraph - #12 is overkill? So I could use #14? (higher the number, thinner the wire, right?)

Correct! You want #10 if you want a heavier wire than #12.....
xzyHollyxyz
Explorer
Aug 11, 2013
OP HERE. I just wanted to say thank you to everyone who has contributed so much of their knowledge to this thread!

It's been, and continues to be, a wonderful discussion.

I'm sure it's been a great learning tool for a lot more people than just me! I know I've sent my Women's RVing Forum over here.

THANKS!

Okay, I'm back to work on my power audit.
xzyHollyxyz
Explorer
Aug 11, 2013
pianotuna wrote:
Hi Mitch,

Yes, when camping there are always some loads on the battery. As mena suggested--measure first thing in the morning.

My fantastic fan is about 3 amps going flat out.

Parasitic loads such as fridge, and detectors are about 1 amp per hour.

Water pump is 7 amps but 15 to 20 minutes of use would drain the water tank.

You can "mix" the wire, but so long as you only have one panel #12 is overkill. It would not hurt for any new wire to be #10, but use what you have for now--and it may be long enough to meet your needs.

On your last paragraph - #12 is overkill? So I could use #14? (higher the number, thinner the wire, right?)

Thanks for the info on the amps! That will help a lot.

I finally found my MaxxFan 7000 power consumption:

Speed 1 = 1.45
Speed 2 = 1.84
Speed 3 = 2.53
Speed 4 = 4.20

I am so excited for the electric supply store to open tomorrow! :)
pianotuna
Nomad III
Aug 11, 2013
Hi Mitch,

Yes, when camping there are always some loads on the battery. As mena suggested--measure first thing in the morning.

My fantastic fan is about 3 amps going flat out.

Parasitic loads such as fridge, and detectors are about 1 amp per hour.

Water pump is 7 amps but 15 to 20 minutes of use would drain the water tank.

You can "mix" the wire, but so long as you only have one panel #12 is overkill. It would not hurt for any new wire to be #10, but use what you have for now--and it may be long enough to meet your needs.

mitch5252 wrote:
I'm working on my "audit" right now.

My overhead lights are 0.9W (LEDs)
My sconce lights are 2.16W (LEDs)

Need to figure out the fridge and the water pump and the MaxxFan. Oh, and the CO detector.

So, since the fridge is running all night, does that mean the battery will never be "at rest" ?

If I wanted a 30' extension cable (instead of the current 10') for the solar panel, would I need to go from 12 gauge to 10 gauge?

Is it possible to "mix" the gauge (connect a 12 to a 10)? (I just bought a 20' 12 gauge and hate to waste the money, cheapo that I am...)

What would be the maximum length for using 12 gauge before having to go to 10 gauge?
xzyHollyxyz
Explorer
Aug 11, 2013
I'm working on my "audit" right now.

My overhead lights are 0.9W (LEDs)
My sconce lights are 2.16W (LEDs)

Need to figure out the fridge and the water pump and the MaxxFan. Oh, and the CO detector.

So, since the fridge is running all night, does that mean the battery will never be "at rest" ?

If I wanted a 30' extension cable (instead of the current 10') for the solar panel, would I need to go from 12 gauge to 10 gauge?

Is it possible to "mix" the gauge (connect a 12 to a 10)? (I just bought a 20' 12 gauge and hate to waste the money, cheapo that I am...)

What would be the maximum length for using 12 gauge before having to go to 10 gauge?

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