The ornamental design for a battery, as shown and described.
FIG. 1 is a front, right perspective view of a battery, showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a top view thereof;
FIG. 5 is a bottom view thereof;
FIG. 6 is a right side view thereof; and,
FIG. 7 is a left side view thereof.
The broken lines present in the figures are included for the purpose of illustrating portions of the article, which form no part of the claimed design.