UPDATE, Corrosion tests show that neither of these strips are what I thought them to be. The results are posted in this thread HERE, so let's see if we can figure what these strips are actually made out of.
2nd UPDATE, both strips seem to be steel based off of resistivity of the metals. Thread name updated to mirror this.
I was planning on redoing my board wiring and decided to test the performance difference of my ebay sourced 0.1 mm and 0.15 mm nickel strips. But it turns out the other strip wasn't pure nickel strip, but rather nickel plated steel strip, so I decided to test them both and declare the results here. Even though the test procedure was quite simple, I took pictures for you guys, so it'll be clear how it was done.
Both strips were also 8 mm wider. Our two strips to be tested with relevant information presented. Sorry, I don't know why the last picture got it's orientation changed.
Testing will be done with a nifty DC-DC buck converter with a display for setting voltage and current limits and it will also show the output power. Power will be supplied via 3S Li-Po.
The strip under test will be attached to the output of the buck converter and then tested by supplying a constant 5 amp current through it.
1st test: Pure Nickel Strip (Actually carbon steel) (8 x 0,10 mm)
Power loss: 1,35 W
Voltage drop: 0,27 V
Strip resistance: 54 mOhm
Material resistivity: 1.2 e-7 (Carbon steel listed in at 1.47 e-7)
Strip felt just a bit warm to the touch
2nd test: Nickel Plated Steel Strip (Actually stainless steel) (8 x 0,15 mm)
Power loss: 4,80 W
Voltage drop: 0,96 V
Strip resistance: 192 mOhm
Material resistivity: 6.6 e-7 (Stainless steel listed in at 6.90 e-7)
Strip felt burning hot for a moment before fingers sucked up the heat.
3rd test: Real Pure Nickel Strip (8 x 0,15 mm)
Power loss: 0.60 W
Voltage drop: 0,12V
Strip resistance: 24 mOhm
Material resistivity: 8.2 e-8 (Nickel listed in at 6.99 e-8)
No noticeable increase in strips temperature.
Nickel Plated Steel Strip is S*#T. Even in this test with it being thicker at 0,15 mm then the pure nickel strip at 0,1 mm, it still had almost 4 times resistance. When taking into account the thickness and resistance and then converting them to a 0,1 mm thickness equivalent. The resistance would be around 290 mOhms for that 350 mm strip. With that kind of resistance if you were to pull a measly 10 Amps through it you would generate 29 Watts of power loss via heat and at that power you will start adding unnecessary heat to your Lithium cells and might even risk a fire at higher currents.(old conclusion)
All three strips mirror pretty well their natural resistivity and is also directly linked to their performance. Pure nickel strip is absolutely dominating the other steel based strips, with stainless steel being particularly s**t. Copper would on the other hand still absolute trash even the pure nickel strip, but comes with the oxidation problem, unless further protected from exposure. So now I know that all three materials are in the circulation and will from now on probably by my strip in bulk from aliexpress, so I can avoid the possibility of getting scammed.
This doesn't actually make things easier as I was trying to source some thicker strip from ebay, but it seemed that almost all the results were steel core, but that only became evident after looking at the item description. Closer look at the descriptions turned out "Nickel Plated Steel Strip" or "99.6% Pure Nickel Plated Steel". Also, always double check the item description if the item name has "pure Ni/nickel plate/plated", as that might be your earliest warning that you're buying nickel plated steel
Genuine pure nickel strip tested and results added to the first post
Pure nickel strip tested in an identical setup as the fake strips so results can now be compared to each other. Also calculated the resistivity of the metal the strip and also added the closest sensible result from https://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity that it compares to in a table of different metals/materials. Results are pretty darn close to what the strips have been concluded to be made out of.