The size of the nickel strip for 18650 LiFePO4 cells can vary depending on the specific requirements of your battery pack. However, commonly used sizes are 0.15mm in thickness and 7mm, 8mm, or 10mm in width. The width can be chosen based on the current that the 18650 nickel strip needs to carry. For instance, a 2cm long strip between 2 cells of 0.15 x 10mm has 0.000912Ω. It’s easier to calculate this way. At 10 amps, it’s dropping 0.1 watt and 0.01 volts between the 2 cells. As you can see, that works out to just about 1 amp per mm of width with .15 strips. Always ensure that the 18650 battery nickel strip you choose can handle the current that your battery pack will be drawing.

Nickel Strip User Guide for 18650 Battery Packs
MaterialColumnWidth(mm)Row Space(mm)Thickness(mm)Cell Holder
Nickel Strip1718.50.12/0.15/0.2N/A
Nickel Strip225.518.50.12/0.15/0.2N/A
Nickel Strip34418.50.12/0.15/0.2N/A
Nickel Strip462.518.50.12/0.15/0.2N/A
Nickel Strip58118.50.12/0.15/0.2N/A
Nickel Strip699.518.50.12/0.15/0.2N/A
Nickel Strip711818.50.12/0.15/0.2N/A
Nickel Strip8136.518.50.12/0.15/0.2N/A
MaterialColumnWidth(mm)Row Space(mm)Thickness(mm)Cell Holder
Nickel Strip1720.20.12//0.15/0.2Yes
Nickel Strip22720.20.12//0.15/0.2Yes
Nickel Strip34720.20.12//0.15/0.2Yes
Nickel Strip467.620.20.12//0.15/0.2Yes
Nickel Strip587.820.20.12//0.15/0.2Yes
Nickel Strip610820.20.12//0.15/0.2Yes
Nickel Strip7128.220.20.12//0.15/0.2Yes
Nickel Strip8148.420.20.12//0.15/0.2Yes