The ornamental design for a battery-based wireless power device, as shown and described.
FIG. 1 is a perspective view of a battery-based wireless power device.
FIG. 2 is a front view of the battery-based wireless power device of FIG. 1.
FIG. 3 is a rear view of the battery-based wireless power device of FIG. 1.
FIG. 4 is a first side view of the battery-based wireless power device of FIG. 1.
FIG. 5 is a second side view of the battery-based wireless power device of FIG. 1.
FIG. 6 is a top view of the battery-based wireless power device of FIG. 1.
FIG. 7 is a bottom view of the battery-based wireless power device of FIG. 1; and,
FIG. 8 is a perspective view of the battery-based wireless power device of FIG. 1 clamped onto a table.
The broken lines shown in the drawings are included for the purpose of illustrating environmental structure and portions of the battery-based wireless power device that form no part of the claimed design.