An apparatus and associated method that contemplate a data storage disc and a motor supporting the disc in rotation. Control circuitry operates to spin up the disc drive by accelerating the motor to a steady state speed by: beginning the spin up by energizing the motor with a primary power; comparing an amount of auxiliary power that is available from a battery to a predefined threshold; and before the motor is accelerated to the steady state speed and if the threshold comparison is favorable, then boosting the primary power by discharging the battery for a predetermined boost interval.