There are various additional ways to measure current in a lead as well. Some ideas are:

1) Measure the voltage drop across a shunt resistor.

2) Use a current transformer where 1 or 2 turns of
the lead wrap through a many turns coil that becomes
the secondary of a sensitive transformer.

3) Use a scheme like shown below. Here full isolation for loads of many 100s of amperes can be achieved.




Michael Karas