It acts as a little resistor as it suggests.
If you pull current through a resistance, you get a voltage drop. The higher the resistance the more voltage drop you get.
For say 20A discharge current on your 3 packs:
V drop = 20 x 0.0021 = 0.042V
V drop = 20 x 0.0038 = 0.076V
V drop = 20 x 0.0052 = 0.104V
So it makes a difference, but if you will notice it is debatable to be honest.
G
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