Battery cable gauge

[bot0611]

This might be a dumb question but i do need to know.

What gauge is the best for battery cables???

my ground cable is messed up (burned) and went to buy a new piece but they only had 6 gauge so i took a piece of 6 gauge but hookd it up with the old cable...already have the triple ground set up so i just need a good thick ground cable.

 

[Copasetic]

I've got 2 gauge on my negative battery cables and 1/0 on my positive ones.

 

[dremu]

It's a question of load and length.

You can get 150A safely through 8AWG ... for a coupla feet. Past that there's enough resistance that the voltage drop is significant.

For a stock or mildly pumped electrical system -- i.e. an alternator of up to, say, 100A and one or two batteries close to it -- #6 should be fine. I can't imagine you'd have runs of more than four or five feet, tops.

You'd want bigger if you have batteries in the bed, a winch, a higher-capacity alternator (like 150A+) and such.

Bigger won't hurt, other than it costs more and can be a pain to route.

Condition is as important as size, though. Lots of guys swear by big 'cuz they replace a 20-year old corroded small wire with a brand new big one and think the wire size made a difference -- when in fact a new wire of the same size as the original would have made the same difference

Also make sure your terminals are clean and tight, etc etc, all the usual electrical stuff.

-- A

 

[Copasetic]

Oops, also forgot to say I"m running a 200 amp alt. with 2 batteries.

 

[blazin_blazer]

just a note...i noticed copasetic mentioned he had 2 gauge on B-(negative) and 1/0 on his B+(positive), iirc, the B- is supossed to be the bigger cable, or at least thats what i remember from basic electronics, b4 moving on to B school(miniture component repair) as a radar tech in USMC...if the ground is smaller, no matter how big the positive, it can't flow any more than the ground will allow.

 

[phreddei166]

Lots of battery cable info here. http://www.custombatterycables.com/

 

[dremu]

just a note...i noticed copasetic mentioned he had 2 gauge on B-(negative) and 1/0 on his B+(positive), iirc, the B- is supossed to be the bigger cable, or at least thats what i remember from basic electronics, b4 moving on to B school(miniture component repair) as a radar tech in USMC...if the ground is smaller, no matter how big the positive, it can't flow any more than the ground will allow.

Yeah, I was gonna say "both should be big" ... but it gets complicated quickly and I was trying to give a simple answer

In a regular circuit -- like the power supplies to your radar units -- the positive and negative sides carry the same flow.

In vehicles, though, the ground half is often a different path. The alternator feeds the battery from the alt post to the battery positive (I'm doing hole flow here, people, not electron flow, so don't whine) ... but then from the negative side we go to the frame, through the frame, to the engine block, and then to the alternator. Some of these latter are carrying other loads as well, i.e. the return side of the battery-to-headlights loads, for instance, so they're seeing more load than the charge wire.

Strictly speaking you prolly want BIGGER grounds in this case 'cuz there are fewer of them and they have to carry the most load ... but in a stock system you just need a good path for the starter as it's the only really high current load.

However, my original answer stands: IMO, for stock/ish electrical systems, reasonably short lengths of clean, new, well-connected 6AWG should do just fine.

And yeah, modified systems are entirely different; I've got everything from #10 to #4 on my trucks, depending on distance and load. (#10 for the headlight relays, length of less than a foot, #8 for the alternator charge wire, maybe two or three feet, and #4 for the winch, battery connector on the truck that has them paralleled, etc.)

-- A

 

[4X4HIGH]

Factory cables are 4 gauge IIRC. I would put at least the factory size or larger. I'm running a 2/0 ground cable (welding cable) on my rig and the factory positive cable on my primary battery which runs all the factory stuff in my blazer. My Aux battery i'm running 2/0 welding cable for both.

 

[bot0611]

Thanks fo all the answers..

 

[tRustyK5]

I ran 1/0 fine strand welding cable for both...it was available, not too spendy and worked quite well IMO.

Rene

 

[bot0611]

In that case in im trouble.

Im running a 2/0 for the + i had 1/0 on the - but i have the triple ground set up, now my 1/0 ground is messed up i hooked besides thoose 3 another ground cable 6 gauge, am i ok??

 

[4x4shortbed]

I replace all my batt cables with welding cable as they crap out. Super fine strands of wire, about $4 a foot at the local farm supply. Works great!

-John

 

[blazin_blazer]

In that case in im trouble.

Im running a 2/0 for the + i had 1/0 on the - but i have the triple ground set up, now my 1/0 ground is messed up i hooked besides thoose 3 another ground cable 6 gauge, am i ok??

uhh, if you mean 1 2/0 and 3-1/0 grounds, the 3-1/0 should flo more than 1-2/0, so if thats the case, your good

 

[blazin_blazer]

welding cable works great, but supossedly a no-no, not sure why...i use oxygen free stereo cable w/a lug soldered on both ends, who is it here that, iirc works on boats and said the welding cable a no no in a different thread somewhere, they said some code tells approved types, was that you ryoken? why welding cable such a no no?

 

[bot0611]

Allright it seems to be ok, thanks guys for all the help

My starter does not drag anymore, like it did before.

 

[JDNobodi]

welding cable works great, but supossedly a no-no, not sure why...i use oxygen free stereo cable w/a lug soldered on both ends, who is it here that, iirc works on boats and said the welding cable a no no in a different thread somewhere, they said some code tells approved types, was that you ryoken? why welding cable such a no no?

I think it has to do with the insulation material and SAE spec. Welding cable probably didn't do any testing to be approved for "Over the Road" vehicles.
I was just going over a catalog I got today from Terminal Supply Company and they list "combination battery and welding cable." The funny thing is there is no SAE rating like regular battery cable which they also sell.
Are you going to get pulled over by the cops and given the Rodney King treatment for having welding cables in your truck? Probably not, (well in my town, the cops will harass you for not having stock cables.) But who cares?
Anyway, I was interest in this thread because I'm trying to figure out which size cable to use for a race car with the battery in the trunk. The person already has 2 gage (not 2/0) welding cable laying around and was wondering if it will be enough. The engine is a high compression SBC.

 

[bot0611]

Well i have a friend whos an electro-mechanic engineer and he told me the bigger the better because a smaller like a 1/0 cable can get hot and all that is lost energy so he told me the thicker the better, in that case it wont get that hot so you dont loose any juice.

 

[dremu]

Well i have a friend whos an electro-mechanic engineer and he told me the bigger the better because a smaller like a 1/0 cable can get hot and all that is lost energy so he told me the thicker the better, in that case it wont get that hot so you dont loose any juice.

Wow, that's a hell of a weird way of looking at it. Smaller wire has more resistance, so it develops more voltage drop, so less voltage is delivered to the load (i.e. the starter or lights or whatever.)

Now, that voltage drop has to be converted into something, so, yeah, heat is involved ... and super-cooling the wire would actually address the issue, but only because the resistance would change. It's sort of cart before the horse, chicken and egg stuff.

Point being that on a stock system, quad-ought cable isn't going to provide any noticeable improvement over, say, #6 or #4. .0001% loss instead of .1% is moot -- you're gonna have more issue with corroded connections, the temperature of the battery, and the phase of the moon =))

-- A

 

[Chevy305]

welding cable works great, but supossedly a no-no, not sure why...i use oxygen free stereo cable w/a lug soldered on both ends, who is it here that, iirc works on boats and said the welding cable a no no in a different thread somewhere, they said some code tells approved types, was that you ryoken? why welding cable such a no no?

Welding cable is not SAE approved because the insullation is not as strong and is not resistant to chemicals and petrolium based substances. Basically the insulation can be penetrated and the cable rots from the inside out. Don't get me wrong though it will last for a while but there are better cables and materials out there.

I personally run the premade autozone battery cables. They are 0 gauge and are pretty cheap too. They sell them in different lengths.

 

[JDNobodi]

Welding cable is not SAE approved because the insullation is not as strong and is not resistant to chemicals and petrolium based substances. Basically the insulation can be penetrated and the cable rots from the inside out. Don't get me wrong though it will last for a while but there are better cables and materials out there.

I personally run the premade autozone battery cables. They are 0 gauge and are pretty cheap too. They sell them in different lengths.

So I was right about the insulation and SAE approval. Make sense because I've seen the insulation on welding cable deteriorate.