Electronic cigarette battery

FIG. 1 is a perspective view of an electronic cigarette battery showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left view thereof;

FIG. 5 is a right view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken line portions of the electronic cigarette battery in FIGS. 1, 4, 6 and 7 represent unclaimed portions of the claimed design and form no part thereof.