If the shunt is 0.01?, however, that would equate to 2V
.. and 400W of heat as well 
Typical 150A shunt I hold in my hand 2w ago was made of 3 parallel 3-4mm diameter brass alloy wires (~80mm long), soldered to two 25x25mm 4mm thick copper holders equipped w/ M8 bolts with M8 screws for current and M3 bolts and screws for voltage measurement. It gave 60mV @150A.