Portable Power Source

FIG. 1 is a front top perspective view of a portable power source of our new design; FIG. 2 is a rear 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 view thereof; FIG. 8 is a bottom view thereof; and, FIG. 9 is an enlarged partial view of area ‘ 9 ’ in FIG. 1 . The dashed broken lines in the drawings illustrate portions of the article that form no part of the claimed design. The dot-dashed broken lines illustrate the boundaries of the portions shown enlarged in the drawings and form no part of the claimed design.