Solar panels

[4x4ord]

I realize that if I did a search I'd find lots of info on solar panels but this is easier.
What do you guys think of a system like this for a guy like me?

We presently have 4 golf cart batteries, a Honda EU2000 and a Xantrex Freedom 2000 watt inverter charger. We often camp where power is not available .... It hasn't been a big deal to get buy with what we have as we are not big power consumers. If we run the generator for 4 hours in the middle of the week we can usually last a week without solar. We have almost never had a need for AC but on the rare occasion that AC is needed the EU2000 gets us by so long as we shut off the fridge and battery charging.

[bpounds]

4x4ord wrote:
... all four panels in series...

This may result in more voltage than your controller is rated to handle. Typically about 100V is max, but you'll need to check your documentation.

That's why series/parallel is so popular. Even if you had 6 panels you could do 3S x 2P, but then you likely would want to upsize the conductors.

Also, it can sometimes be easier to run parallel conductors instead of pulling and replacing with larger size. Every situation will be different.

[pianotuna]

Series parallel allows me to get some charging done even in leafy shade (about 7 amps at solar noon). Full output is about 17 amps. I use a Blue Sky controller--but would pick something with a higher capacity, as I have no "head room" to add another pair of panels. i.e. I can't add another set in series, nor can I add more in parallel.

[time2roll]

Series? What controller do you plan to use?

[4x4ord]

bpounds wrote:

4x4ord wrote:
^^^ It's 10 gauge wire, so I guess if all 4 panels are hooked in series the 10 gauge would be heavy enough. Is that a bad idea?

Not a bad idea, in fact it is what you should do with an MTTP controller. With 4 panels, I would suggest 2-pairs in series, those pairs in parallel. That will be well within reasonable current for 10ga wire, as well as reasonable voltage.

Folks around here tend to get stuck in the weeds over excessively sized conductors.

The kit came today. It would sure be a quick simple install to wire all four panels in series. Going to a 2 pairs in series then parallel will require a bit more material and expense. I guess I'll stew about it for a couple days before doing anything. We usually like to camp in the trees so under partial shading an all series install would limit the output significantly..... but on the other hand I think even wired in series we would find when the sun is high those four panels are enough to get us back to a full charge on a daily basis anyway.

[bpounds]

4x4ord wrote:
^^^ It's 10 gauge wire, so I guess if all 4 panels are hooked in series the 10 gauge would be heavy enough. Is that a bad idea?

Not a bad idea, in fact it is what you should do with an MTTP controller. With 4 panels, I would suggest 2-pairs in series, those pairs in parallel. That will be well within reasonable current for 10ga wire, as well as reasonable voltage.

Folks around here tend to get stuck in the weeds over excessively sized conductors.

[4x4ord]

The 10 gauge pre wiring goes up from the basement; into the bathroom/hallway wall; into the attic; through the attic and down into that coat closet. It isn't fastened anywhere so I think I will be able to use it to pull heavier wire through the same path. I took the wall panel off inside the bathroom. I think it is going to be worth it to have a little heavier wire going up to the roof so I can run the panels is parallel.

[blofgren]

4x4ord wrote:


The pre wiring is not actually much of a deal. I believe it's just wires in the hallway wall that drop down to the basement. The charge controller in that case would mount on the wall in the hallway and wires would be drilled up to the roof top through the top plate. This prewiring going down to the basement is not heavy enough to run any kind of amperage.
I think I'm going to use 8 gauge wire (possibly even 6 gauge just because I have a piece kicking around) from the roof top down to the basement where I will mount the charge controller. I haven't looked it over close yet to determine where I will run the wire but I might pull that same wall panel off and drill up through the top plate to the roof and then down though the bottom plate into the basement.

Gotcha. Down inside the coat closet and under the shower stall into the basement would be pretty easy too if getting it inside the wall turns out to be problematic.

[4x4ord]

^^^ It's 10 gauge wire, so I guess if all 4 panels are hooked in series the 10 gauge would be heavy enough. Is that a bad idea?

[laknox]

A lot of the older "pre-wired for solar" rigs simply had wires coming down through the reefer vent on the roof, and pretty light wire, too.

Lyle

[4x4ord]

The pre wiring is not actually much of a deal. I believe it's just wires in the hallway wall that drop down to the basement. The charge controller in that case would mount on the wall in the hallway and wires would be drilled up to the roof top through the top plate. This prewiring going down to the basement is not heavy enough to run any kind of amperage.
I think I'm going to use 8 gauge wire (possibly even 6 gauge just because I have a piece kicking around) from the roof top down to the basement where I will mount the charge controller. I haven't looked it over close yet to determine where I will run the wire but I might pull that same wall panel off and drill up through the top plate to the roof and then down though the bottom plate into the basement.

[blofgren]

4x4ord wrote:

Old Days wrote:
I put a lot of Dicor under the bracket and of course on top. We spend time in Wyoming and Montana and the cross winds are terrible, so I really try and make sure the panels are secured.

I will get some no sag Dicor.

Did you ever find the prewiring inside of your trailer? I don't see where they are on these trailers; I'm sure my 2005 Citation was labelled on an inside wall.

[laknox]

4x4ord wrote:
I realize that if I did a search I'd find lots of info on solar panels but this is easier.
What do you guys think of a system like this for a guy like me?

We presently have 4 golf cart batteries, a Honda EU2000 and a Xantrex Freedom 2000 watt inverter charger. We often camp where power is not available .... It hasn't been a big deal to get buy with what we have as we are not big power consumers. If we run the generator for 4 hours in the middle of the week we can usually last a week without solar. We have almost never had a need for AC but on the rare occasion that AC is needed the EU2000 gets us by so long as we shut off the fridge and battery charging.

You want to see just about the ultimate solar system in an RV? Check out my cousin's blog on their '64 GM bus rebuild. www.beginningfromthismorning.com. Basically, they've got 8 commercial grade solar panels on the roof with a Nissan Leaf battery to power the whole thing.

Lyle

[4x4ord]

Old Days wrote:
I put a lot of Dicor under the bracket and of course on top. We spend time in Wyoming and Montana and the cross winds are terrible, so I really try and make sure the panels are secured.

I will get some no sag Dicor.

[4x4ord]

Lwiddis wrote:
Shouldn’t go over 5.5 feet with 400 solar watts (22 amps or so) using 10 gauge wire, wandering. That’s what comes in that kit.

I should get the kit this week and I might have to buy a bit of wire/connectors etc. I'm thinking I will wire the panels in two banks of two and feed 24 volts to the controller.