Waste Heat Calculation Help

I calculated that my nickel is 0.27mm2 per tab going from one cell to the next and the length from cell to cell (the part hanging in the air) is about 6mm so on a 20S pack I have 21pcs of 6mm meaning a total of 12.6cm length of 0.27mm2 pure nickel.
Each row (P) has a max of 10A.
I want to calculate the waste heat in celsius coming out of the nickel to know if I should look into copper.

The amount of heating power (in Watts) is R * I^2 (Resistance * Current^2).
The resistance of the wire (in Ohm) is c * (length in meters) / (area in mm^2)
Use c=0,0171 for copper and c=0,0693 for nickel.
So 12.6cm of 0.27mm2 wire would have a resistance of 8mOhm in copper and 32mOhm in nickel.
To calculate how hot the copper/nickel will get is hardly possible because it will depend on many factors.

The conductivity of copper is 4 times better, but nickel is easier to weld and corrosion resistant.

hias9 said:

The amount of heating power (in Watts) is R * I^2 (Resistance * Current^2).
The resistance of the wire (in Ohm) is c * (length in meters) / (area in mm^2)
Use c=0,0171 for copper and c=0,0693 for nickel.
So 12.6cm of 0.27mm2 wire would have a resistance of 8mOhm in copper and 32mOhm in nickel.
To calculate how hot the copper/nickel will get is hardly possible because it will depend on many factors.

The conductivity of copper is 4 times better, but nickel is easier to weld and corrosion resistant.

Click to expand...

Yeah, that I know, I used a calculator from google and aware of the difference between the conductivity/resistance of the two but the part I'm having trouble with is the watt dissipation...

Just R * I^2, so at 10A 0.8W for copper or 3.2W for nickel.

hias9 said:

Just R * I^2, so at 10A 0.8W for copper or 3.2W for nickel.

Click to expand...

Umm...how do I convert that to temp rise in the conductor?

rg12 said:

hias9 said:

Just R * I^2, so at 10A 0.8W for copper or 3.2W for nickel.

Click to expand...

Umm...how do I convert that to temp rise in the conductor?

Click to expand...

Empirical or Virtual?

Virtually you can use BTU/Min calculations.

Empirical;

https://www.digikey.com/en/videos/t/tensility/what-is-a-temperature-rise-test

Thermal equations get very complicated. The question you are asking, earns the best of experienced engineers, about a quarter million dollars per year, or even much more when employed. I am impressed by the kind of questions you ask... they are great questions...

I ( am certain that I ) do know, but I want to check to see that I am correct before i lay it out here. Gimmie a min, and I'll see if I cannot let ya know how it works a little better.. ( gotta ask someone else who knows.. ) .. with the math.... ( I am not the best at the math.. ) ?!?!?!?!? Lol. Greek to me. Whats it mean? Idk.







For example, programs to do thermal modeling are very expensive.. typically.. cause only engineers use them and all engineering gets paid for or else there is no product... Sothere is no pirated thermal software.. anywhere....


( I wonder if there is a good free thermal modeling software? Huh IDK)

.... if you do not have a company license... ( ie 500$-1000$ for one program to do this, given opotons. . (winsteam is an example.. )

Familiarize yourself with some of this information / concepts / equations... ;


https://en.wikipedia.org/wiki/Thermal_simulations_for_integrated_circuits

https://en.wikipedia.org/wiki/Thermal_management_(electronics)

https://en.wikipedia.org/wiki/Heat_generation_in_integrated_circuits

IPC-2221-A: (.pdf) (Re: CONDUCTION, § 7.1.1)

http://www-eng.lbl.gov/~shuman/NEXT/CURRENT_DESIGN/TP/MATERIALS/IPC-2221A(L).pdf

I guess it would be easier to just run 10A through my conductor with a thermistor stuck to it...

rg12 said:

I guess it would be easier to just run 10A through my conductor with a thermistor stuck to it...

Click to expand...

Yeah, that's probably what I would do. Lol. Sounds like the best plan.

Heres another person, whom comes to mind, knows a tom more than I, and deserves the credit, when thinking along critical lines of this nature.

#105 pretty much sums it all up,. around the 16 min mark.. In particular. This guy ( is great). Lol.

https://www.youtube.com/watch?v=8ruFVmxf0zs&list=PLvOlSehNtuHu6Jjb8U82eKQfvKhJVl0Bu

TDP. Thermal Design Power. All that.

rg12 said:

hias9 said:

Just R * I^2, so at 10A 0.8W for copper or 3.2W for nickel.

Click to expand...

Umm...how do I convert that to temp rise in the conductor?

Click to expand...

This is a really interesting video of how to do the calculations for wire in open air.
https://www.youtube.com/watch?v=QNS0LrlRHbs
[youtube]QNS0LrlRHbs[/youtube]