lithium is a highly reactive metal (even more reactive than sodium IIRC), and if a lithium i was calibrating a clamp ammeter once, and part of the procedure required testing it at 300A. one method used a 300A power supply and #00 ga wire, but there was an alternate method in the manual using a 75A supply and a loop of 4 turns of #4 wire (75Ax4 turns=300A-turns). i ended up using the alternate method. every time i turned up the current control on the supply, the wire loop moved to be perpendicular to the earth's magnetic field, and would return to it's original position when i turned the current off.