parasitic battery drain

To clarify what he is doing here, by using an external resistor, he is actually MAKING a low range current meter the same as is "in" your multimeter, except that by using an external resistor, it's almost impossible to damage the meter. "Good" meters are fuse protected

And to further clarify, when he says he measured "933 millivolts" because of the resistor, this translates directly to "933 milliamps" or .9 amps