FIG. 1 is a front, perspective view of a portable power supply showing our new design;
FIG. 2 is a rear, perspective view thereof;
FIG. 3 is a front, elevational view thereof;
FIG. 4 is a rear, elevational view thereof;
FIG. 5 is a left, side elevational view thereof;
FIG. 6 is a right, side elevational view thereof;
FIG. 7 is a top plan view thereof;
FIG. 8 is a bottom plan view thereof;
FIG. 9 is an enlarged view of the area “9” shown in FIG. 1;
FIG. 10 is an enlarged view of the area “10” shown in FIG. 1; and,
FIG. 11 is an enlarged view of the area “11” shown in FIG. 2.
The broken lines in the drawings depict portions of the portable power supply that form no part of the claimed design.