... interesting... here's an online calculator.

Wire Gauge Size and Resistance Calculator - Inch Calculator
Voltage Drop Calculator - Inch Calculator
Have not taken EE class. Is this right?

#6 copper wire @ 5 ft

50A circuit

245V power

To charge 10 kW

@ 12A, voltage drop of 0.059v, so 0.71W loss

= 3.4 hours, so 2.41W loss on the wall.

= Add 200W loss per hour, so 682.31W loss

@ 16A, voltage drop of 0.0786v, so 1.26W loss

= 2.55 hour, so 3.21W loss

= Add 200W loss per hour, so 511.26W loss

@ 24A, voltage drop of 0.1179v, so 2.83W loss

= 1.7 hour, so 4.81W loss

= Add 200W loss per hour, so 342.83W loss

@ 32A, voltage drop of 0.1572v, so 5.03W loss

= 1.28 hour, so 6.44W loss

= Add 200W loss per hour, so 261.03W loss

Going from #6 wire to #4 wire, resistance drops from .0020 to .0012 ohm (so 40% less W loss on the wire)