bad69marrow

Hi im redoing somebodys electrical nightmare on battery cables i was wanting to no which to use 1-gauge or 1/0 gauge battery cable or welding cable ????? Its going be in drag car with 2 batteries n trunk also is it best to run both the hot wire postive an negative cable both cables from the starter all the way to trunk ????? Or do i just run the hot wire ???? An run the negative ground wire couple feet an ground at engine an chassis an trunk ??????????? Any help be appreciated i need to no befor i buy battery cable or welding cable thanks everbody

jayvee34

I would say either gauge, as they both will handle a lot of amps. Just a short
cable of the same gauge to the frame, and then another to the engine or trans.,
for a good ground should be OK. In my opinion one cable from the starter to
the positive side of the battery and short cable to each positive post to tie
the two battery's together, and the same for the two ground posts of each battery's.

BigBlockMark

I have used welding cable in the past with no issues. I have been told that it is not a good idea because the welding cable is not rated for vibration common in a race car. Supposedly the fine strands can break and lower the load capacity. Also finding copper terminals with the right size holes for the studs and bolts used in a race car can be hard. If you want to use 00 wire and need 5/16" stud size, the welding terminals are usually 3/8".

bad69marrow

Thanks guys for the information was very helpful

oldandtired

For the negative curcuit to complete itself, it runs like a spiderweb looking for the negative side of the battery, running thru all the welds and chasing peripheral runs. I highly recomended you run a short ground cable to the chassis AND then run your 1/0 to the engine block.
If you have a good positive with a 1 gauge or 1/0 run you can engauge the starting and charging system. Then use a positive block for your electronics. (Some manufacturers say to run their electricics on a seperate lead from the + side of the battery).

JPO - I do not believe in running welding cable. The large number of fine wires actually absorbes (reduces) amps, giving you a lower hit at the end of the run. In english....DC current runs straight thru the wire and several strands of larger copper wire handles the load better that dozens (hundred?) of strands of welding cable.

indcontrols

also agree with not using the welding cable on a race / performance vehicle. Further, typical battery cable is usually bare copper (= corrosion), and covered in PVC (melts easily and in some cases the insulation can be removed with your thumbnail).
As for the ampacity, it not only varies with gauge size, but also with temperature rating of the insulation, as well as how it is installed (ie; in raceway or free air, bundled with other cables, etc.)

Hopefully the amp rating chart below appears properly. While many other things should be taken into account (ambient temperature, length of run, etc.), this gives a good idea of how using GOOD wire allows you to use a smaller gauge for a given load, and using EXCELLENT wire is even better.

For racing builds or even on street cars, I use a SILICONE RUBBER wire that has a FIBERGLASS BRAID over it and is sealed in an acrylic coating. It is rated for 600v (1,000v Military), and you basically need an angle grinder to destroy the jacket. It is not as flexible, costs more, and it has a larger stranding than welding cable and the strands are TPC (tin-plated copper). Guys that build 4x4's, ATV's, pulling trucks, this is the only way, you just can't break it. I use the same thing in smaller gauge to go down to the starter solenoid, etc. due to the high heat rating and the braided jacket.

Insulation Materials

Polyethylene Polypropylene PVC (Irradiated) Kynar (135° C) Kapton
Neoprene Polyethylene Nylon (Crosslinked)TPE's PTFE
Polyurethane (High Density) Silicone
PVC
Copper Temp. 80° C 90° C 105° C 125° C 200° C
30 AWG 2 3 3 3 4
28 AWG 3 4 4 5 6
26 AWG 4 5 5 6 7
24 AWG 6 7 7 8 10
22 AWG 8 9 10 11 13
20 AWG 10 12 13 14 17
18 AWG 15 17 18 20 24
16 AWG 19 22 24 26 32
14 AWG 27 30 33 40 45
12 AWG 36 40 45 50 55
10 AWG 47 55 58 70 75
8 AWG 65 70 75 90 100
6 AWG 95 100 105 125 135
4 AWG 125 135 145 170 180
2 AWG 170 180 200 225 240
1 AWG 211 265 280
1/0 AWG 245 305 325
2/0 AWG 283 355 370
3/0 AWG 328 410 430
4/0 AWG 380 475 510
Single Conductor in Free Air 30° C Ambient Temperature
________________________________________

Derating Factors for Bundled Conductors

Bundle # Derating Factor (X Amps)
2 - 5 0.8
6 - 15 0.7
16 - 30 0.5

annamarks

I would say either gauge, as they both will handle a lot of amps. Just a short
Speed Test