A power distribution system, the system comprising: a DC bus configured to deliver operating power to a DC load; a conversion circuit configured to receive AC power and convert the received AC power to DC power that is provided to the DC bus; a battery system configured to provide DC power from a battery to the DC bus; and, a controller configured to determine a first amount of DC power to be provided to the DC bus by the conversion circuit, determine a second amount of DC power to be provided to the DC bus by the battery system while the first amount of DC power is provided to the DC bus by the conversion circuit, and control the conversion circuit and the battery system such that the conversion circuit provides the first amount of DC power to the DC bus and the battery system concurrently provides the second amount of DC power to the DC bus; wherein the controller is configured to determine the first amount, determine the second amount, and control the conversion circuit and battery system as part of transitioning between a first state in which the conversion circuit is not providing DC power to the DC bus to a second state in which the conversion circuit provides a third amount of DC power to the DC bus, the third amount being greater than the first amount; characterized in that the controller is configured to transition between the first state and the second state in stages over a specified time period, such that the controller increments an AC power contribution of the conversion circuit by a predetermined number of amps and decrements a DC contribution of the battery by N amps when the AC power contribution is less than a predetermined level and a predetermined number of seconds have passed since the last increment, to prevent inrush currents from exceeding a second predetermined level. a DC bus configured to deliver operating power to a DC load; a conversion circuit configured to receive AC power and convert the received AC power to DC power that is provided to the DC bus; a battery system configured to provide DC power from a battery to the DC bus; and, a controller configured to determine a first amount of DC power to be provided to the DC bus by the conversion circuit, determine a second amount of DC power to be provided to the DC bus by the battery system while the first amount of DC power is provided to the DC bus by the conversion circuit, and control the conversion circuit and the battery system such that the conversion circuit provides the first amount of DC power to the DC bus and the battery system concurrently provides the second amount of DC power to the DC bus; wherein the controller is configured to determine the first amount, determine the second amount, and control the conversion circuit and battery system as part of transitioning between a first state in which the conversion circuit is not providing DC power to the DC bus to a second state in which the conversion circuit provides a third amount of DC power to the DC bus, the third amount being greater than the first amount; characterized in that the controller is configured to transition between the first state and the second state in stages over a specified time period, such that the controller increments an AC power contribution of the conversion circuit by a predetermined number of amps and decrements a DC contribution of the battery by N amps when the AC power contribution is less than a predetermined level and a predetermined number of seconds have passed since the last increment, to prevent inrush currents from exceeding a second predetermined level.