The ornamental design for a batterytab, as shown and described.
FIG. 1 is a perspective view of a battery tab according to our new ornamental design;
FIG. 2 is a front view of the battery tab of FIG. 1;
FIG. 3 is a rear view of the battery tab of FIG. 1;
FIG. 4 is left side view of the battery tab of FIG. 1;
FIG. 5 is a right side view of the battery tab of FIG. 1;
FIG. 6 is a top view of the battery tab of FIG. 1; and,
FIG. 7 is a bottom view of the batter tab of FIG. 1.
The broken lines in the drawings show the boundaries of the claimed design and/or environmental structures of the battery tab that form no part of the claimed design.