Splice connections for lengthening solar panel wires?

[Directshort]

Dumb newbie question but to extend the wires can I just cut the connectors off of the plug end of the solar panel leads and splice another similar gauge wire using something like a simple butt connector?

Asked another way is there magic sauce in the wiring and connectors or is it just simple copper wire inside carrying the current from the little magic box under the panel?

 

[John Frum]

Dumb newbie question but to extend the wires can I just cut the connectors off of the plug end of the solar panel leads and splice another similar gauge wire using something like a simple butt connector?

Asked another way is there magic sauce in the wiring and connectors or is it just simple copper wire inside carrying the current from the little magic box under the panel?

MC4 connectors are waterproof and UV resistant.
Whatever joinery you swap in will likely have to have those characteristics.
Cutting the connectors off the panels will probably decrease their resale value and overall utility to boot.

 

[snoobler]

I just buy 10awg UV resistant solar wire with MC4 connectors on the ends available in a variety of lengths.

Will has some links on his site:

Off Grid Solar Wires and Connectors

Building a vehicle mounted solar power system? Let me help.

www.mobile-solarpower.com

 

[Zil]

I bought uv resistant extension cables with MC4 ends from Windy Nation.

 

[toms]

I go the other way and always hardwire my PV with quality automotive style butt joiners and UV resistant heatshrink.

MC4 connectors are built for speed of installation, they aren’t as good as a well crimped connection.

 

[snoobler]

I go the other way and always hardwire my PV with quality automotive style butt joiners and UV resistant heatshrink.

MC4 connectors are built for speed of installation, they aren’t as good as a well crimped connection.

Disagree 100%. They are crimped as well as any other connection with the proper tool.

 

[toms]

Sure, but then they rely on a male/female barrel connection which may be subjected to fretting corrosion. (i have seen this, along with water ingress as causes of failure).

 

[Directshort]

My splice will be inside the van so sounds like it should work.
Thanks for the input really appreciate it.

 

[Hedges]

Sure, but then they rely on a male/female barrel connection which may be subjected to fretting corrosion. (i have seen this, along with water ingress as causes of failure).

Then consider anti-corrosion compound and/or heatshrink with glue inside.

"quality automotive style butt joiners"

Is that an oxymoron?

What voltage strings are you using?
I don't think I'd enjoy using a crimping tool on wires approaching 600 VDC.
This isn't the kind of terminal/crimper linemen use to tap off hot overhead AC power lines.

It does look to me like MC4 was made to be cheap and based on a Molex sheetmetal pins, compared to MC3 which appears to be higher quality.

https://www.amazon.com/MC4-Solar-Connector-Pins-set/dp/B013OAAX2W

Amazon.com: MC3 Solar Connector Pins 10 set. : Patio, Lawn & Garden

Amazon.com: MC3 Solar Connector Pins 10 set. : Patio, Lawn & Garden

www.amazon.com

 

[Zil]

MC 4 connectors are the best there are for the purpose. Most panel manufacturers void the warranty if the factory installed MC4 are removed.

 

[iceledoar]

A straight copper to copper connection will always be better. Any dry connection will have an air gap and cause resistance.

 

[toms]

What voltage strings are you using?
I don't think I'd enjoy using a crimping tool on wires approaching 600 VDC.

I only use 80V, wouldn’t change my method if i was using 600+V

Automotive engine bay wiring harnesses have to survive in a MUCH harsher environment than a connector ziptied beneath a PV panel.

As mentioned earlier, an MC4 union already contains 2 crimped connections, and a barrel union. (i agree using anti fretting compound would be good, but i’ve yet to see an installer do this)

Direct crimping removes 2 potential failure points.

The OP was asking if it was OK, to direct crimp connect PV wiring. The answer is absolutely yes.