I claim the ornamental design for a battery powered chainsaw, as shown and described.
FIG. 1 is a right-rear perspective view of the battery powered chainsaw;
FIG. 2 is a front view of the battery powered chainsaw shown in FIG. 1;
FIG. 3 is a rear view of the battery powered chainsaw shown in FIG. 1;
FIG. 4 is a left side view of the battery powered chainsaw shown in FIG. 1;
FIG. 5 is a right side of the battery powered chainsaw shown in FIG. 1;
FIG. 6 is a top view of the battery powered chainsaw shown in FIG. 1; and,
FIG. 7 is a bottom view of the battery powered chainsaw shown in FIG. 1.
The subject matter shown in dashed lines, and any surfaces of the design not shown, including interior surfaces, form no part of the claimed invention.