The ornamental design for an electric naildrillportablepower supply, as shown and described.
FIG. 1 is a perspective view of an electric nail drill portable power supply showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a bottom view thereof; and,
FIG. 7 is a top view thereof.
The broken lines in the figures are for the purpose of illustrating portions of the electric nail drill power supply which form no part of the claimed design.