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Discussion Starter · #1 ·
Hi Folks,
I'm making some bus bars to join together 400v tesla pack in a diffirent physical layout to original so i need new bus bars.
I happened across a sheet of 4mm stainless steel and i was pretty excited to use it to make bus bars. mostly because it wont corrode easily.

A quick look on the internet reveals stainless steel has a higher electrical resistance.
Cooper for example has a resistivity of 1.68×10−8
Aluminium 2.65×10−8
carbon steel 1.43×10−7 (note the minus 7 not minus 8)
stainless steel 6.90×10−7 (note the minus 7 not minus 8)

So i can easily imagine copper is the most desirable choice. That said is Stainless steel still a problem? should i just make them slightly larger to compensate?
Original was 25mmx3mm (75mm2) how much larger would be desirable? 25mmx4mm (100mm2)?

Aluminium is easy enough for me to get but i thought since i have the stainless, why not?
 

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Discussion Starter · #3 ·
well that settles it. great info thanks!
Just confirming, would it be 6.9/1.68 = 4.1 instead of 69/1.68=41?
in either case, thats a huge stainless steel strap.

I priced some copper yesterday. I need 4mm x 70mm x 300mm to cut the shape i need for each strap. the closest i could get was 5mm x 90mm in 4 metre length for $282!
I'll see if i can change the design to make them smaller.
 

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Discussion Starter · #6 ·
Thanks Brian_, now i understand why the decimal point moved.

Thanks PSTechPaul, i was thinking of similarly dodgey ideas. Like collecting scrap copper and using my forget to make some forged copper bus bars. Cheaper, but way dodgy. I think given the amount im spending on the car, i dont think i should complain about $282 :)

THanks for your advice.
 

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Discussion Starter · #12 ·
I knew stainless steel having a higher resistence would need to be thicker, which is why i initially suggested 4 x 25, but i didnt know to what scale. now i know its 41 times thicker! so not practical to use stainless steel.

The shape is a roughly a 'Z' on its side to create an angled bus bar to join stacked modules in series. I cant make that out of one piece without having a really wide piece of copper to start with. I dont want to solder or join the pieces, just to avoid complexity. Its a lot of wastage but i'll do it right the first time.
 
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