hello
lets stay physical to the wireing
i measure the factory cable
line from/back motor 0,034 Ohm
That means loose power of
P=R*I²
0,034* 60² = 122,4W energy loose over the wire at 60A
0,034*120²=489,6W at 120A
with 13KW/400A that would men
0,034*400²=5440W Power lose over the wire...... and...