Power-backup capabilities are provided by implementing a variety of different methods, systems and devices. According to one such implementation, an energy storage circuit is powered using a variable voltage controlled to limit the current draw from a power supply, to charge the energy storage circuit for providing backup power to a solid state drive (SSD) type of data storage arrangement. Certain applications involve controlling the power draw from the power supply, in response to feedback and/or power drawn from other circuits, as may be applicable to an initial startup of the energy storage circuit and/or the initial startup of a larger system in which the energy storage circuit is employed.