Battery maintainer

FIG. 1 is a perspective view of the ornamental design for the battery maintainer;

FIG. 2 is a front view of the battery maintainer of FIG. 1 ;

FIG. 3 is a left side view of the battery maintainer of FIG. 1 ;

FIG. 4 is a right side view of the battery maintainer of FIG. 1 ;

FIG. 5 is a top view of the battery maintainer of FIG. 1 ;

FIG. 6 is a bottom view of the battery maintainer of FIG. 1 ; and,

FIG. 7 is a back view of the battery maintainer of FIG. 1 .

In these drawings, the broken lines illustrate environmental features that form no part of the claimed ornamental design.