The ornamental design for a batterycover, as shown and described.
FIG. 1 is a front, right perspective view of a battery cover, showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a top view thereof;
FIG. 4 is a bottom view thereof;
FIG. 5 is a right side view thereof; the left side view being the same; and,
FIG. 6 is a perspective view thereof, shown in an environment of use.
The broken lines present in the drawings are included for the purpose of illustrating environmental subject matter, which forms no part of the claimed design.