Cable Size

[Kontiki]

I have a Watt meter to wire in to the solar panel controller to the battery, the meter wires have 14 AWG on them & look about the same size as the wires from the solar controller to the battery but could do with extending them. Was going to get some cable from Europarts but they have them listed in amps, 5,8,17 & 27. Which is the closest to 14 AWG? They have 37% off if you order online to click & collect.

 

[trevskoda]

Divide the volts of the panel into the wattage,so say 15v into 100 sil give you size,always
go a bit over size as it helps voltage drop.

 

[Kontiki]

The panel is 100 watt so 100 / 15 = 6.6 amps so that means the 8 amp would be sufficient.

 

[edina]

14AWG is equiv to 2.08mm², so 2.5mm² would be your best choice. Europarts don't seem to list cable size, so I would buy from a supplier that does.

eg 14A 21A 30A 12v Automotive Cable 1m-100m Auto Wiring Loom Marine 1 1.5 2.5mm Amp | eBay

 

[shortcircuit]

How long is your extension as you would be better to up cable size if too long?

 

[wildebus]

I have a Watt meter to wire in to the solar panel controller to the battery, the meter wires have 14 AWG on them & look about the same size as the wires from the solar controller to the battery but could do with extending them. Was going to get some cable from Europarts but they have them listed in amps, 5,8,17 & 27. Which is the closest to 14 AWG? They have 37% off if you order online to click & collect.

I wouldn't rely on the attached cable being the right size and something to work to.
There are quite a few guides available to cross-reference Amps to Cable Gauges, and also conversion charts to convert AWG to Metric.

 

[trevskoda]

The panel is 100 watt so 100 / 15 = 6.6 amps so that means the 8 amp would be sufficient.

Yes if short run,any long runs double that,10/15 amp cable.

 

[wildebus]

And bear in mind there are two factors to consider when sizing cable on ELV (Extra Low Voltage) systems.

1) Current Carrying Ability (Ampacity)
2) Voltage Drop

Often you will want to 'oversize' a cable to avoid excessive voltage loss.

A calculator like this will show the effect - Voltage Drop Calculator

 

[ricc]

as a general rule the cable cost is negligable, low volt systems are badly effected by voltage drop on too thinl cables.... id use the fattest cable that will fit in the terminals.

 

[bobj808]

12 volt planet website has a good cable sizing guide and calculator. Bob

 

[Kontiki]

Used 17 amp cable which seems to be the same size as 14 awg, it only needed extending less than a foot to mount the meter in convenient place.