A stand-alone motor unit for use with a piece of power equipment includes a housing, a flange coupled to the housing on a first side thereof and a slot in the flange. The slot is configured to receive a protrusion of the piece of power equipment. An electric motor is located within the housing. A power take-off shaft receives torque from the motor and protrudes from a second side of the housing adjacent the first side. A battery pack provides power to the motor.