But the max temp is much lower on pvc cables… Basically 6 awg silicone should be equivalent to something like 2 awg pvc
i guess you are right, i just went by wire gauge amp ratings, 6ga is good for 65A, that is what threw me off, then i looked at booster cables sold, and most of them are also 6ga, i guess when wires are relatively short, a second or so burst of hugh current wont get them too hot.
Any reasonable good starter cable should have 25mm² or 50mm² about AWG 4 or 1 copper or even more aluminum gauge
Yes just look on the cables in the car they don’t use much more copper from battery and electronic relays to starter motor
400 or 800A ratings are just for short bursts, average starter draw is lower
You have to be careful many Chinese products sell copper plated aluminum conductors,
usually you can simply feel the quality of the cable just by weight 50mm² copper are really dense and heavy
Not in this case.
If you are not sure that contact surfaces are medical clean, you need maximum contact pressure.
Maximum contact pressure=minimum surface area.
Clamp jaws should have sharp teeth, this is the clue for low resistance joint in various (bad) conditions.
Sharp edges on copper jaws won’t last long.
Where do you get these numbers?
I have never seen a petrol car with 50 sq.mm wires from the battery to the starter. You probably could find so big wires 30-50 years ago.
I would say that 250Amps is what you need to start 10-15y.o. bus diesel (T4/T5/Transit), 150Amps is more than enough for any 1.0-2.0 petrol car. Most modern cars have a lightweight battery, small starter, low-density oil - it’s hard to find parts that will assume even 1kw while idle turning.
P.S. I’m speaking about peak amps measured with a clamp meter when the ignition is starting. There is always some probability that “slave” battery is dead, “master” battery is big and full and clamping one to another will cause a bigger peak. Generally, this is not what you need - smaller area wires can save your connectors and eyes from sparks.
how do you test if the tips of jaws are copper, and not brass, so it is clearly seen on photo, cuz i found my old clamps, and it looks like copper in person, but on photo it looks a lot yellower, like brass.
Try a small file - if it is copper, recently opened are will have pink
tint.
I think brass is also slightly magnetic because it’s alloyed with a bit of steel
Not normal brass (Cu/Zn).