The ornamental design for a batterycharger, as shown and described.
FIG. 1 is a front, bottom, right side perspective view of a battery charger, showing our new design;
FIG. 2 is a rear, top, left side perspective view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is a right side elevational view thereof; and,
FIG. 7 is a left side elevational view thereof.
The broken lines depict portions of the battery charger that form no part of the claimed design. The dot-dash broken lines represent a boundary between claimed portions and unclaimed portions of the battery charger and form no part of the claimed design.