OT - Jump Leads

[George Layton]

Hi Chaps - A bit of help required from the collective wisdom of the list.

I need to buy some new jump leads as mine are old and a bit corroded. The information given by many of the vendors has me a bit confused!

>From the Porsche PET the starter motor on my GTS is rated at 1.5kW. Even if this is based on a 10V DC supply  (I understand the battery can drop to this when cranking the engine) then the current would be 150 Amps.

The recommended Porsche battery for my 928 has a CCA rating of 340 Amps.

But, most of the vendors stipulate that for an engine over 3.5 litres you need jump leads that are rated at anything from 500 to 700 Amps! This is obviously way more than the starter motor draws and considerably more than the battery can deliver.

Is there a flaw in my logic somewhere?

What would you guys recommend?

Cheers,

George.