Portable Power Bank

FIG. 1 is a front perspective view of a portable power bank, showing my new design; FIG. 2 is a rear perspective view thereof; FIG. 3 is a front view thereof; FIG. 4 is a rear view thereof; FIG. 5 is a left side view thereof; FIG. 6 is a right side view thereof; FIG. 7 is a top view thereof; FIG. 8 is a bottom view thereof; FIG. 9 is an enlarged detail view of area 9 in FIG. 1 ; and, FIG. 10 is an enlarged detail view of area 10 in FIG. 2 . The dash-dash broken lines in the drawings illustrate portions of the article that form no part of the claimed design. The dot-dash broken lines in FIGS. 1 , 2 , 9 , and 10 illustrate the boundaries of the portions shown enlarged in the drawings and form no part of the claimed design.