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Adapter for using normal 16awg extension cord 110v-120v for solar?

leesamuelm

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Jun 28, 2021
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I have a small 100w solar setup with a two 12v battery in parallel with about 560 wh capacity

I was wondering, if I could somehow use an extension cord 16AWG to connect my panel to my charge controller to save me from having to plug my battery in next to the solar panel? I checked and 16AWG should handle 15amps which is more than my 100w panel produces.

I would wire up the MC4 to nema5/edison plug on the solar panel end and then on the other side a nema5/edison plug to mc4 on the charge controller side?

I now it would be easier to just get a long run of MC4, but that would be another long cord rather than just having adapters that I could keep in my battery box.

Why is this a horrible idea before I go and make adapters lol
 
Well, one negative is that extension cord does not have weather proof connections. It also depends on how long the run is. If it was 50 feet and your panel puts out 12V @8.33A then you would lose 35% of your power in the cable and the voltage at the end would be 7.85V.

So unless your run is really short, 16AWG isn't big enough. Look up a voltage drop calculator and you can determine what size wire you need.
 
As long as you get your polarity right on the spades there's nothing stopping you at all. It's just another adapter, although a much more convenient one for most homeowners. :) Would you need to do a nema -> MC4 for the charge controller? Most of those are just screw terminals so you'd just need the nema to bare wires for that end.

The only issue would be that 16awg is pretty thin and you'd probably run into voltage drops over long distances. The adapters would work fine but you might want to use a heavier cable.
 
Thanks for the wisdom. The run is about 50 feet or so and the voltage drop would be a concern. I'll see if I have a more heavy duty extension cord.

I will definitely make sure polarity is dummy proof. Also the Nema to bare wire would work for the charge controller end.
 
My setup is fairly temporary, the panel sits on the lawn, and my batteries and charge controller are in a water-resistant box, that I usually put out in the morning and bring inside in the evening. This way, I reduce the risk of low temp charging as the batteries and box is room temp when I bring it out in the morning and would not cool down fast enough to be in danger of lower than 0c charging. (I know charging warms it up a bit too)

Ideally I would rather keep the charging box on my porch and run the extension cord to the panel.

Thanks for the advice folks! I'll try the adapters and see if the run isn't too long that i drop too much voltage
 
Check the cable type of the extension cord. A lot of them are only intended for in-house use, and for short periods of outside use.

Moisture generally isn't an issue unless the cord is damaged, but UV-resistance is. Exposed to UV (sun) for long periods might cause the cable to deteriorate soon.

If you're having a lot of rodents, they might add their share of damage to the cable as well.
A more rugged extension cord is no problem. Not sure if the wire types are identical on your side, but in the EU I would prefer H07RN-F wires.
Cheaper ones tend to be PVC based and those aren't always up to long term UV exposure and become pretty stiff in low temps (thus damaging the insulation faster)
 
Check the cable type of the extension cord. A lot of them are only intended for in-house use, and for short periods of outside use.

Moisture generally isn't an issue unless the cord is damaged, but UV-resistance is. Exposed to UV (sun) for long periods might cause the cable to deteriorate soon.

If you're having a lot of rodents, they might add their share of damage to the cable as well.
A more rugged extension cord is no problem. Not sure if the wire types are identical on your side, but in the EU I would prefer H07RN-F wires.
Cheaper ones tend to be PVC based and those aren't always up to long term UV exposure and become pretty stiff in low temps (thus damaging the insulation faster)
Oh good to know. My cable is a light duty indoor outdoor cable but it's either 50 or 100 feet so and at 16awg it's probably not worth using. I'll just spend the extra 2 minutes going to my panel
 
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