Motorized vertical blind assembly

A motorized vertical venetian blind window covering assembly, comprising:

• an elongated head rail comprising a first longitudinal face end, a second longitudinal face end, a top wall and pair of depending front and rear walls extending between the first and second longitudinal face ends and defining an inner headrail space for housing at least one covering material carrier and a drive mechanism for moving the covering material;
• an elongated motor assembly couplable to the rear wall of the headrail so that it extends parallel to the head rail,
• the elongated motor assembly comprising an elongated first housing comprising a first housing end and a second housing end and defining an internal space between the first housing end and the second housing end, a motor with a drive output extending outside the first housing end of and couplable to the drive mechanism in the head rail, a battery pack and a motor control board disposed within the internal space of the first housing,
• the elongated motor assembly further comprising a supplementary drive shaft having a first shaft end and a second shaft end, the first shaft end couplable to the drive output of the motor such that the supplementary drive shaft is an elongated extension of the drive output and of the first housing.