Joined

·
47 Posts

So I am trying to get a better understanding of how to design bus bar for a 12s12p module using 18650's. i understand that bus bars current carrying capacity is also dependent on temperature rise. but how do you know which cross sectional area to use?

Let's assume that the bus bar is 100mm L x 20 mm W x 5mm thick.

Also, let's say that the cells are connected long way along the 100mm distance with the bus bar in between.

(+)=======(-).

From my reading, my assumption in my gut says i should do 20x5x1.2= 120amp

With 1.2 amp/mm^2 for copper

But this doesn't account for temperature rise

Also, why would we not do 100x5x1.2=600amps? Is it because the current is going to find the shortest path from Pos to Neg? Lastly, is there a larger calculation that can be made that includes temperature rise and thermodynamic effects?

Thanks in advance!