The ornamental design for a solar wireless powerbank, as shown and described.
FIG. 1 is a perspective view of a solar wireless power bank showing my new design;
FIG. 2 is a perspective view thereof from another angle;
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; and,
FIG. 8 is a bottom plan view thereof.
The broken lines shown in the drawings are included for the purpose of illustrating portions of the solar wireless power bank that form no part of the claimed design.