As far as power goes, to pass 300+ amps, GM uses multi-layer copper ribbon that is 0.078" thk x .679" wide x >36" long. So a full inch wide should OK for 500amps? A circuit board calculator tells me no, but how does GM do it then?
That's why I got the copper ribbon.
EDIT: No matter what I look at, nothing agrees with GM battery cable dims. But I did read that if the connector ends are silver plated, it has a higher rating.
It boils down to
How many volts/watts can I afford to lose
How hot will it get
I am using 0.5mm x 20mm copper strips with the terminals 42 mm apart
That will have a resistance of 0.072MilliOhms
I use two strips on top of each other so that is 0.036 mOhms
Each of my strings has 10 of these so - 0.36 mOhms
(The other connections are cells nose/tail)
Each string has a max current of 240 amps (15C) - 0.08 volts drop
Not significant in a 130v string
(four strings in my pack)
Each will produce 2 watts of heat
Again not a problem for the 10 seconds I can use 15C
This drops to 1 watt for "continuous 10C"
Copper is easy to cut, the best way to make the holes for the bolts would be with a hole punch
I used wood cutting drills
The type that look like metal drills except they have a point and two sharp outer tips
I found they made much nicer holes than proper metal drills
I get 0.4 mOhms for your GM strips - so 0.2 volts drop and 100 watts at 500 amps