Thread: Cable Sizing for High Amperage Applications

Originally Posted by slug_burner

On your calcs you would be dropping about 300 Watts of heat on the 33mm2 to your rear winch per cable. A bit much, best go up in size as others have recommended.

Yep,

I will run;

• 70mm2 for the rear winch (hopefully through chassis rail)
• 33mm2 or 50mm2 for the front winch depending on location of the control box and length of cable required
• 33mm2 for the compressor and rear batteries.

I am getting a price on wedling cable today.

I have not been able to find a local shop with the 70mm2 battery cable and most dont seem to have the 50mm2 either.

Originally Posted by CJT

Yep,



I have not been able to find a local shop with the 70mm2 battery cable and most dont seem to have the 50mm2 either.

I got my 70mm2 of ebay from a bloke up your way (QLD) his ebay name was sparkey000red

50mm2 is 17.50 p/m
70mm2 is 21.50 p/m

plus shipping

Better yet, if you have a mate who is a sparky, get him to put it on his account and you would get it much cheaper (wholesale) through stores like Middys.

Originally Posted by Toppa

I got my 70mm2 of ebay from a bloke up your way (QLD) his ebay name was sparkey000red

50mm2 is 17.50 p/m
70mm2 is 21.50 p/m

plus shipping

Better yet, if you have a mate who is a sparky, get him to put it on his account and you would get it much cheaper (wholesale) through stores like Middys.

Thanks for that.

I am getting a price on welding cable through my mate who owns a fabrication shop, so I will compare the prices from both.

I know its not maths but for a real world example:
-I have a length of 35mm2 welding cable from underseat batteries to towbar of the fender.
-175A Anderson that plugs to Warn9000 on the big boat trailer.
-Earth is to the passenger chassis rail - same rail as the main battery earths.
-Battery setup is two N70 marines in parallel NO switch/solenoid/black majic box.
-The tinnie weighs in at about 3500kg, retrieve is a double line pull over about 5m.

It winches fine, sure voltage drops but cable, connectors, winch motor do not get hot - it does the job perfectly well, certainly such that I have no burning desire to change things (pun intended!).

A pos and neg of 70mm2 would be a bear to run and what will you use to terminate it? Dinse connectors? Or will it be hardwired to a winch solenoid box - if so it will it fit???

Its also nice in that I have an ATV winch on the smaller boat trailer (it drives that with ease) and if I need to jump start someone I would have no hesitations off it either.

Anyways, back to the theoretical

Steve

Originally Posted by Toppa

I got my 70mm2 of ebay from a bloke up your way (QLD) his ebay name was sparkey000red

50mm2 is 17.50 p/m
70mm2 is 21.50 p/m

plus shipping

Better yet, if you have a mate who is a sparky, get him to put it on his account and you would get it much cheaper (wholesale) through stores like Middys.

I recieved a price for welding cable;

35mm2 @ $7.85 p/m
50mm2 @ $10.60 p/m
70mm2 @ $13.50 p/m

All prices excluding GST.

really good prices there, i paid about that for 70mm 5 years ago, and i'm a sparky.
but copper was at a rather high price back then

I agree, about half the price of anything I found at retail prices.