A battery 20 of electric mower 1 is received in a battery receiving recess 40 of the electric mower. A battery side connector 132 is provided in a front end of the battery, and a mower side connector 44 is provided in a front end of the battery receiving recess, and configured to be electrically connected to the battery side connector when the front end of the battery is pushed against the front end of the battery receiving recess. A section of guide rails provided on the bottom surface of the battery receiving recess are configured to guide guide ribs provided on the lower surface of the battery so as to laterally align the battery with respect to the battery receiving recess as the battery is displaced toward the front end of the battery recess.