1. Skin effect applies only to AC current and is negligible up to tens if not hundreds of kilohertz.
2. The current ratings on jumper leads are apparently meaningless - very few if any of the ones I have seen would actually carry their rated current for more than a few seconds without melting at least the insulation. This is ignoring the fact that their clips would not stand it either - in fact the contact area on most of them would be guaranteed to provide enough resistance to limit the current enough to prevent damage to the cable, albeit not to prevent damage to the battery terminal and clip. And if you are actually trying to run starter current through the cable (as opposed to giving a battery a boost and an assist), the voltage drop will be more of a problem than the heating effect. If you are only boosting the battery, lighter cables can be an advantage from the point of view that they limit the current to prevent damage to the donor vehicle's battery and electrical system from the virtual short presented by the dead battery in the vehicle being started.
3. As stated welding cables are multi-stranded to provide flexibility - in fact they make excellent jumper cables, but the clips on the ends still tend to be the main limitation.
John
John
JDNSW
1986 110 County 3.9 diesel
1970 2a 109 2.25 petrol
Bookmarks