Cable length and size

[Welshman]

Im fitting a 120w solar panel on a pergola at the bottom of the garden ( in sun all day), but i want it to possibly run my power bank thats on the deck at the house end…..direct line to house is around 15mtrs, but around the fencing were i will tac the cable would be around 25mtrs……

can i use a cable that long with a dc connector straight into the bank and if so, what thickness of cable should i run???

 

[Bobert]

Im fitting a 120w solar panel on a pergola at the bottom of the garden ( in sun all day), but i want it to possibly run my power bank thats on the deck at the house end…..direct line to house is around 15mtrs, but around the fencing were i will tac the cable would be around 25mtrs……

can i use a cable that long with a dc connector straight into the bank and if so, what thickness of cable should i run???

You can run a cord that long the size of the cable depends on the amps the panel puts out.

 

[rmaddy]

Assuming a panel voltage around 24V and an amperage of about 6A, for a 50m roundtrip of wire you would want at least 8AWG or 10mm² wire.

Make sure your solar charge controller can accept wire that size.

 

[Welshman]

Assuming a panel voltage around 24V and an amperage of about 6A, for a 50m roundtrip of wire you would want at least 8AWG or 10mm² wire.

Make sure your solar charge controller can accept wire that size.

its 12v………why a round trip and not just 25mtrs to the deck, why do i need to go back the other way???

its also a power bank, with built in charge controller and a dc input for charging.

its one of these

 

[rmaddy]

Your solar panel does not put out 12V. Post the full specs of the panel so we can be sure of the numbers.

Most solar panels have an MC4 connector at the end of each wire. How do you plug the solar panel into your little power station?

 

[Welshman]

Your solar panel does not put out 12V. Post the full specs of the panel so we can be sure of the numbers.

Most solar panels have an MC4 connector at the end of each wire. How do you plug the solar panel into your little power station?

its a 120w 12v panel…….and the power station comes with an mc4 to dc cable like this

 

[rmaddy]

Please post the specs of your solar panel or post a link to the panel you bought. The "12V" part is just a marketing term, not a specification of an actual voltage.

 

[Welshman]

Please post the specs of your solar panel or post a link to the panel you bought. The "12V" part is just a marketing term, not a specification of an actual voltage.

Its 100w not 120w

 

[rmaddy]

OK, so the Voc is 24.3V and the Isc is 5.21A. Given that voltage and current (as I guessed in my original answer) then my original statement for wire size stands.

The problem is that the adapter to connect your panel to the power station assumes a much short wire therefore it has much smaller gauge wires. The reason to use a much thicker wire for the long distance you need is to help with voltage drop. If you used the same size wire that comes with the solar panel (probably 12AWG) then your panel's output will be reduced by maybe 15%-20%. By using the thicker I wire I mentioned you eliminate most of that reduction.

So you need a pair of 8AWG PV extension cables for the 25m from your panel to the power station. If you take the 15m route then 10AWG extension cables would be fine.

 

[Welshman]

OK, so the Voc is 24.3V and the Isc is 5.21A. Given that voltage and current (as I guessed in my original answer) then my original statement for wire size stands.

The problem is that the adapter to connect your panel to the power station assumes a much short wire therefore it has much smaller gauge wires. The reason to use a much thicker wire for the long distance you need is to help with voltage drop. If you used the same size wire that comes with the solar panel (probably 12AWG) then your panel's output will be reduced by maybe 15%-20%. By using the thicker I wire I mentioned you eliminate most of that reduction.

So you need a pair of 8AWG PV extension cables for the 25m from your panel to the power station. If you take the 15m route then 10AWG extension cables would be fine.

Cant do the 15m route as it would mean digging up my lawn or running the cable in the air and theres no chance of me doing either…..i already have 25mtrs of extension cable with mc4 connectors at 8awg, so can use those

cheers