The ornamental design for a portablecharger, as shown and described.
FIG. 1 is a bottom perspective view of a portable charger of my design, in which the prongs are in a retracted position;
FIG. 2 is a second bottom perspective view thereof, in which the prongs are in an extended position;
FIG. 3 is a bottom plan view thereof, with the prongs in the retracted position;
FIG. 4 is a front elevation 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 back elevation view thereof.
The dot-dash broken lines in the drawings illustrate the boundaries of the claimed design, the unshaded portions within forming no part of the claimed design.