The ornamental design for a battery powered waterpump, as shown and described.
FIG. 1 is a perspective view of a battery powered water pump showing my new design.
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof.
FIG. 4 is a side view thereof;
FIG. 5 is an opposite side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The features presented in broken lines represent unclaimed portions of the battery powered water pump and form no part of the claimed design. The flexible hose shown in FIGS. 4 and 5 is illustrated moved to the side so as to fully illustrate the flexible hose and the remainder of the battery powered water pump.