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nissan
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Juat a quick question,what size cable should I use to tun to th eback of the Patrol from the second battery and will I need to run two or would i be able to pick up the nuetral off bodywork somewhere in the back?

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nissan
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run a 6mm twin with a sheath from aux battery with a fuse of course. will be fine for fridge and will have a good earth right off battery terminal
 

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When they lablel cable and say 6mm twin etc, the actuall wire diametre of each is half, so 6mm twin is two wires of 3mm each. 4mm twin is actually 1.84mm each
 

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GQ Dual Cab. TD42Ti with fruit.
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Larger cable also suffers less from voltage drop, especially over longer runs. Good thick cable is good insurance I reckon.
 

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nissan GU iv 2006
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Larger the better. I would use 6mm min = 4.25mmsquare. 8 gauge would be better.
Patrol addict 2.5mm?????????WTF
way to thin.
Don't forget its 5 meters away in the rear, the bigger the cable less voltage drop which = less amp draw.
Run the earth back to the battery as others have stated(the body is rubber mounted etc)
 

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On the Engel website they state that the 40 litre has a max draw of 2.5 amps, if the fridge is the only thing that's going to be running on the cable then I don't see the point in getting carried away with giant cable, Like patrol addict said, the voltage drop at the amount of current is going to be bugger all.
 

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BORDERTREK 4X4 & FABRICATION
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to add to all this confusion.. the standard Engel cord i have in my hands right now states 16AWGx2c

which has a diameter of 1.29mm according to this chart. American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies
Yeah but the cords only about 1.5 - 2mts long ;) It's size of the other supply cable and it's distance to the power source itself that's important.
On the Engel website they state that the 40 litre has a max draw of 2.5 amps, if the fridge is the only thing that's going to be running on the cable then I don't see the point in getting carried away with giant cable, Like patrol addict said, the voltage drop at the amount of current is going to be bugger all.
It can get higher than that in stinking hot conditions when the fridge runs more often than not. Buts it's an Engel and they are pretty efficient at keeping cold :)
When they lablel cable and say 6mm twin etc, the actuall wire diametre of each is half, so 6mm twin is two wires of 3mm each. 4mm twin is actually 1.84mm each
Nah mate, the 6mm twin core I use is 4.54mm.sq in each core. Almost double the square mm of 5mm auto cable core.

The rule of thumb I use for 12V is after doing calc's if the volt drop will be more than 0.36V I up the cunductor size to get it below that.
 

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Patroladdict is right, 2.5mm is fine. I've got 2.5mm running to the rear for my fridge & have had for 4 yrs with no issues.

Just go 1 size up from what your fridge draws ie if your fridge draws 20A go for a 30A wire. Simple!!

Look at the size of the wire that goes from your alt to your batt to charge it & you'll see what patroladdict is saying is right.
 

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yeah sudso, length does matter. since my secondary battery is internally mounted, the wiring only requires to be short. its less than a meter to my fridge from my battery. if i could, id chop 90% off the cord. but its my parents fridge so im not about to cut cables etc.. so ive used about a 30cm length of cable from the battery to circuit breaker then connected the engel cord to other side of circuit breaker.
 

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nissan patrol gu 2007
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I've just done this job and run fused 6mm wire to the 40L Engel via cig outlet . Probably overkill but these wire runs have a habit of being built on and have other things eventually hanging off it. For a few more dollars running this 6mm is worth it particularly for little voltage drop. Easy decision with no calculation.
 

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Larger the better. I would use 6mm min = 4.25mmsquare. 8 gauge would be better.
Patrol addict 2.5mm?????????WTF
way to thin.
Don't forget its 5 meters away in the rear, the bigger the cable less voltage drop which = less amp draw.
Run the earth back to the battery as others have stated(the body is rubber mounted etc)

no need to run earth straight to battery . the body is earthed! if it wasnt you would have 50million wires from everything electrical going back to the battery from factory.
if your still paranoid about earth problems just run a thick earth wire from battery to body and you wont have to run an earth to your battery everytime!!:rolleyes:

its a good idea to run bigger positive wire than needed incase you decide you want to run higher current devices like compressors, inverters etc
 

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Interesting discussion about auto wire at this web site:

Wiring Woes and Auto Cable - Caravan and Motorhome Books.

"Sold by auto parts stores, auto-electricians, etc, auto-cable's rating is of its outside diameter, not the conductor size. That is it includes the thickness of the insulation – and this varies. All this absurd rating thus tells you is what size hole the cable can pass through."

I dont know how well it relates to Australia but probably explains why wire sold at auto shops is useless for heavy duty wiring.
 

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NISSAN 1989 GQ PATROL
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I've just done this job and run fused 6mm wire to the 40L Engel via cig outlet . Probably overkill but these wire runs have a habit of being built on and have other things eventually hanging off it. For a few more dollars running this 6mm is worth it particularly for little voltage drop. Easy decision with no calculation.
X2 Bugger trying to work it all out!! I just run thicker aswell:D:cheers:
 

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BORDERTREK 4X4 & FABRICATION
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Interesting discussion about auto wire at this web site:

Wiring Woes and Auto Cable - Caravan and Motorhome Books.

"Sold by auto parts stores, auto-electricians, etc, auto-cable's rating is of its outside diameter, not the conductor size. That is it includes the thickness of the insulation – and this varies. All this absurd rating thus tells you is what size hole the cable can pass through."

I dont know how well it relates to Australia but probably explains why wire sold at auto shops is useless for heavy duty wiring.
Not so, any auto wiring worth it's salt always states the sq.mm size of the conductor on the packaging. Then you know exactly what you're getting. 6mm and so on do not always have the diameter as stated or the proper conductor size for the given OD.
cheers
 

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BORDERTREK 4X4 & FABRICATION
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Just stick with a good thick twin core wire and be done with it.

Why the hell do people want to use the thinest stuff that will just do the job, or skimp on an earth wire. The amount you save will not be anywhere near worth it when your fridge starts to play up while out on a long holiday in a remote location with food going off OR heaven forbid WARM BEER.

Patrols often have a poor earth to the body anyway so also run an earth back to battery. Now shut up and hand me a coldie.
 

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its not that we want to use the thinnest.. we want to know what will work!

ive read every thread in the last 26 pages of auto elect forum in regards to wiring and fridges. and it differs EVERY person that posts.

discrepancies lay between language used AWG vs ISO vs mm^2 vs S n B etc etc. no one speaks the same language. there for everyone asks a new question! ive recently asked a simple question and been given a million answers all in different languages. leading me to just go with one answer outta the lot. am i right??? who knows?????

as in most threads you all talk bull**** amongst yaselves leaving those asking in no better position than they started.

id have hoped for better.
 
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