Power Bank

FIG. 1 is a front, left and top perspective view of a 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 view thereof; FIG. 6 is a right side view thereof; FIG. 7 is a top plan view thereof; FIG. 8 is a bottom plan view thereof; FIG. 9 is the expanded state diagram of FIG. 1 ; FIG. 10 is the expanded state diagram of FIG. 2 ; FIG. 11 is another expanded state diagram of FIG. 2 ; and, FIG. 12 is the expanded state diagram of FIG. 4 . The broken lines shown in the drawings illustrate portions of the power bank that form no part of the claimed design.