Hi folks, the major difference between welding cable and automotive cable is that with welding cable, there are far more but much thinner copper strands. This is to make the welding cable very flexible without having it break due to fatigue, while auto cable could be used as welding cable, because the cable is not very flexible, in a very short time, the strands would start to break through continues flexing of the cable.

B&S and AWG cable sizes are identical because B&S ( Brown & Shape ) cable sizing was the for runner to AWG ( American Wire Gauge ) and both are based on the cross sectional area of the cable. This means the cross sectional area of the copper will be the same no matter what company makes it.

As pointed out in previous posts above, cross sectional sizing is the ONLY way to grade cable. Even though we do have a standard for AC cable, Australia is one of very few developed countries not to have a standardised automotive cable size and for some unknown reason, nearly all cable manufactures in Australia, mark their cable using the useless Automotive Cable sizing which has no standard and varies greatly in cross sectional size from one manufacturer to another. One good point is that many manufacturers, like Tycab, also mark the cable with the cross sectional size as well, EG. 7.9mm2, which is 8B&S or 8 AWG or 8G

Another point, in most cases, when cable has a current capacity marked on it, this usually refers to the amount of current the given cable can handle before the insulation start to heat and has nothing to do with the maximum current capacity of the same given cable.

So when buying automotive cable, first know what sort of current you are planning to be carrying through the cable. There are so many things you have to take into consideration when trying to workout what cable size to get that best suites your needs.

For example, in the above situation, if the vehicle is normally easy to start then 6B&S ( about 13.5mm2 ) would do the job and as 10mm2 twin is commonly available, you may get away with this small a cable.

On the other hand, if the vehicle takes a bit to turn it over in the morning then 4B&S, or even 2B&S would be needed to do the job.