Portable Power Bank

FIG. 1 is a front, left, and top perspective view of a portable power bank, showing my new design;

FIG. 2 is a rear, right, and bottom perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a left side elevation view thereof;

FIG. 6 is a right side elevation view thereof;

FIG. 7 is a top plan view thereof; and,

FIG. 8 is a bottom plan view thereof.

The broken lines depict portions of the portable power bank in which the design is embodied that form no part of the claimed design.