Extension cord for solar?

SoCal Tom

Explorer
Ok, just started a solar setup. Currently a single 50w panel and a cheap PWM controller. The plan is to make a foldable 100 watt system when budget permits. Anyhow, I have a 10g 115v extension cord. What if I made MC4 to 115v adapters? Any reason I couldn't get a dual purpose out of that cord?
Tom


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I've done exactly that for my solar setup, wiring in a female AC plug to MC4 connectors at the panels and have a male AC plug dongle at the input to my MPPT controller. Works great and I can extend with additional extension cords, as needed.

I run either 2 or 4 panels (100W, Renogy Eclipse panels) out remotely in the sun and wire 2 panels in series for higher voltage to the MPPT controller and less voltage drop through the extension cord. In series, I'm seeing about 35V out of the panels. If I run 4 panels, I use two MC4 combiners to parallel the two sets of 2 that are wired in series. I've seen as high as 340 watts into the system after the MPPT controller with optimum panel alignment to the sun...that was on a 50', 12GA extension cord. My cable from the MPPT controller to the batteries is #8, but it's only about 4' long.

If your foldable system is made up of two panels, I'd definitely wire them in series and put the PWM controller close to your rig, not at the panels...assuming it can handle the input voltage of the 2 panels in series. 10GA may be overkill if you can wire in series and have the higher voltage, but if you've already got a 10GA extension cord, it will buy you a few more % of efficiency.

Cheers!
 

john61ct

Adventurer
Illegal because potentially fatally dangerous.

Cut off the ends and properly crimp in Andersons rated for the wire gauge's max amps at 12V.

Anderson as the "multi-use standard" for your rig, then make up adapters for specialized connectors like MC4 or ciggie socket (only if really needed, max 6A)
 

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Verkstad, your concern is noted...and I would hope that the OP is aware of these potential issues, as well.

Those risks were considered, but where and when I am using solar components, 120VAC will not be present to be an issue. My MPPT controller is not permanently affixed to my rig and is only set up when I deploy my solar panels, so nothing for some bonehead to plug into inadvertently. I have monitor for voltage, current, watts and accumulated watt hours, so I am able to keep an eye on typical system performance. My solar capacity is well in excess of my typical needs, so I can tolerate a certain amount of detriment creeping into the system, though I'm somewhat anal about having good, clean connections, appropriately sized for the load involved.

Cheers,
 

rayra

Expedition Leader
The other consideration is the bulk of the extension cord, when you can use a simpler two-strand and smaller gauge wire for your solar extension that would take a lot less stowage space.
 

SoCal Tom

Explorer
I recognize the inherent safety risk. The Panel has MC4 connectors, and I would put MC4s on the controller end. The adapters would convert the 120V cord to an MC4 extension. I always carry the cord, because sometimes I camp in RV parks with power, and other times I carry a small generator. The extension cord is already there, a couple of adapters take less space in my small rig than another set of cords.
I appreciate the concern, I did buy a 20ft MC4 extension, but if I need more, I want to have an option.
Thanks
Tom
 
I recognize the inherent safety risk. The Panel has MC4 connectors, and I would put MC4s on the controller end. The adapters would convert the 120V cord to an MC4 extension. I always carry the cord, because sometimes I camp in RV parks with power, and other times I carry a small generator. The extension cord is already there, a couple of adapters take less space in my small rig than another set of cords.
I appreciate the concern, I did buy a 20ft MC4 extension, but if I need more, I want to have an option.
Thanks
Tom
Pretty much the same rationale here...I have a small Honda 650W genny for situations where it might be rainy or the area unsuitable for solar. If I'm trying to get from point A to point B quickly and driving until almost dark, but want some amenities, I'll snag an RV spot somewhere and plug in. In any event, I've got an AC extension cord that I can use without having to carry another cable strictly for solar.
 

SoCal Tom

Explorer
If your foldable system is made up of two panels, I'd definitely wire them in series and put the PWM controller close to your rig, not at the panels...assuming it can handle the input voltage of the 2 panels in series. 10GA may be overkill if you can wire in series and have the higher voltage, but if you've already got a 10GA extension cord, it will buy you a few more % of efficiency.

Cheers!
It looks like running them in series isn't helpful with the PWM. From what I've read although the PWM can handle 50V, what it does is just drop the voltage to 14.7 volts ( or less) without increasing the amperage, hence the value in an MPPT controller.
Tom
 
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