Aluminum vs Copper Wire

[NoMadYesHappy]

Any feedback on the merits / detractors of using stranded copper plated aluminum over 100% copper wire for the cables leading from the solar panels to the Charge Controller to the Batteries?  3X 100W Renogy mono panels, BlueSky 3000i CC, 2X cheap Universal AGM 100Ah batteries.  I'll be using AWG 4, about 25 feet each pole.  I'd opt for the copper ... just having a hard time finding 100% copper in that gauge from an online seller.

 

[NoMadYesHappy]

Any feedback on the merits / detractors of using stranded copper plated aluminum over 100% copper wire for the cables leading from the solar panels to the Charge Controller to the Batteries?  3X 100W Renogy mono panels, BlueSky 3000i CC, 2X cheap Universal AGM 100Ah batteries.  I'll be using AWG 4, about 25 feet each pole.  I'd opt for the copper ... just having a hard time finding 100% copper in that gauge from an online seller.

PS: What about finer stranded cable compared to more course strands or solid?

 

[highdesertranger]

I would go with copper. it shouldn't be hard to find. I like Genuinedealz for heavy gauge wire,

http://www.genuinedealz.com/

tinned copper marine grade wire.

also powerworx for wire,

https://powerwerx.com/?utm_source=bing&utm_medium=cpc&utm_term={keyword_text}&utm_campaign=Powerwerx+-+Exact&utm_adgroup=Powerwerx&mkwid=sZd4nGhFy_dc&pcrid={creative}&plc={placement}&pkw=powerwerx.com&pmt|=e&utm_content=Powerwerx

powerwerx is actuall in Yorba Linda, CA. down the mountain from you. maybe 50 miles away. they do will calls, so if your order was big enough you could drive and pick it up save on shipping. my mom lives a couple of miles away let me know if you are going. they are great for Anderson connectors. highdesertranger

 

[Trebor English]

You can use aluminum but there are issues.  You need a bigger wire to have the same resistance.  Aluminum is prone to cold flow.  That's where you tighten a screw terminal and the plastic aluminum flows and then the screw is loose, even with no vibration.  Loose connections have resistance, they make hot spots.  Aluminum in contact with brass or copper creates a tiny battery leading to galvanic corrosion.  Aluminum wire develops a skin of aluminum oxide.  Unlike rust it does protect the underlying aluminum but it is not a good conductor.

On the other hand, equivalent resistance aluminum can be cheaper.  Just be sure you know how to solve all of the problems.  In any case, don't bury the wire in a wall where it will be hard to replace it all.

 

[highdesertranger]

I do apartment maintenance and every few years we go into the apartments and retighten the terminals on the breaker boxes. they have aluminum wire. I couldn't believe on how loose some are and apartments don't drive down the road with all the vibrations. just saying. highdesertranger

 

[Trebor English]

In 1975 I bought a house wired with aluminum.  There was a circuit that went from the breaker box to a duplex outlet in the living room and then 3 feet away to the kitchen on the other side of the wall.  The fridge was powered through that outlet in the living room.  The ivory colored outlet turned brown and had a funny smell.  That's how I learned to tighten them all annually and to use conductive anti oxidant grease.

Aluminum can work.  It can burn your house down too.  Copper can fail but aluminum wiring is looking for trouble.  

I bought some wire for my van.  It came copper clad aluminum.  I trashed it.  Just my opinion.

 

[NoMadYesHappy]

Thanks, y'all ... copper it is. Found some.

 

[John61CT]

100% copper, don't even consider anything else.

UV resistant insulation also.

personally I stick to UL1426 tinned "boat cable" for any project expected to last more than a couple years

​ http://www.bestboatwire.com

 

[Canine]

I don't cheap out on wire because I want to squeeze every last drop out my system and want to be as safe as possible. During the winter that is critical. Ancor wire is excellent, but it's expensive. I do have some wire that is rated UL 1426 but not Ancor brand; it's still really good wire. Lots of junk wire out there.

 

[NoMadYesHappy]

I don't cheap out on wire because I want to squeeze every last drop out my system and want to be as safe as possible. During the winter that is critical. Ancor wire is excellent, but it's expensive. I do have some wire that is rated UL 1426 but not Ancor brand; it's still really good wire. Lots of junk wire out there.

Yah, I like efficiency, too.  4 AWG is over kill, but has a lower resistance ... less loss, more safety, as you say.  I am a little worried that it might not fit in the BlueSky terminals.  But, it has 4 gauge listed in the manual ... so, it ought to ... ?

 

[Canine]

Yah, I like efficiency, too.  4 AWG is over kill, but has a lower resistance ... less loss, more safety, as you say.  I am a little worried that it might not fit in the BlueSky terminals.  But, it has 4 gauge listed in the manual ... so, it ought to ... ?

10 gauge should be enough unless your charge controller is a long ways away. Even with three panels, 10 awg should be enough for less than a 3% voltage drop. I only go up a size or two up not 4 sizes up. If 4 awg fits and you already have it, it won't hurt, so don't worry about that. You may have some trouble getting it to fit, though. 4 awg is kinda big.

 

[John61CT]

it has 4 gauge listed in the manual ... so, it ought to ... ?

Yes, and going a little thinner at the ends is OK anyway when the size is bigger to reduce voltage drop.

The main reason to use expensive quality wire stock, and proper crimping, quality terminators etc is primarily safety, but also **longevity**.

After 3-5 years a shoddy job, even if no fire risk will start randomly failing, require tedious troubleshooting and rewiring.

If I was doing a buildout where the base vehicle was on its last legs and the owner was on an extreme budget, then compromises are completely appropriate, not on safety of course, but no point tripling a $500 job in that case.

 

[DLTooley]

Any reason why doubling a smaller guage wire would be a safety risk? Say if your existing install had voltage drop?

 

[NoMadYesHappy]

Any reason why doubling a smaller guage wire would be a safety risk?  Say if your existing install had voltage drop?

None that I can think of ... good option!  Thx! 

 

[Canine]

DLTooley, one wire will be shorter and one wire won't have as good of a connection; therefore, one wire will bear more of the load. It can be done, but that is a jerry rigged way to do it. A temporary fix.

 

[John61CT]

+1

 

[NoMadYesHappy]

AWG4 ordered and en route.

 

[NoMadYesHappy]

Before ordering my power cables, I looked up some dimensional info ... thought I'd share.  Probably redundant on several levels, but it makes me feel like I am contributing! 

Wire Gauge Diameters ...
https://www.tedpella.com/company_html/wire-gauge-vs-dia.htm