A respiratory treatment apparatus provides respiratory treatment with improved power management control to permit more efficient power consumption and power supply units, such as battery powered operation. In one embodiment, power management prioritizes the flow generator (104) over other accessories such as the heating elements (111, 135) of a humidifier (112) and/or a delivery tube. The flow generator may control operations of the heating elements as a function of a detected respiratory cycle. For example, the timing of operation of the heating elements may be interleaved with the portion of an inspiratory phase of the respiratory cycle to permit the flow generator to operate during a peak power operation without a power drain or with a lower power drain from these components. Operations of distinct sets of components of the system (e.g., different heating elements) may also be interleaved to prevent simultaneous peak power operations.