In one aspect of the invention, a portable floor care system with manually interchangeable AC and DC vacuum motor head assemblies for use in cleaning hard surface flooring may include: a reservoir defining an interior space operable to hold a cleaning liquid; a spigot fluidly connected to the reservoir interior space, the spigot manually adjustable through a range between a fully open position and a fully closed position, whereby when the reservoir contains a cleaning liquid, a user may dispense and regulate the flow of the cleaning liquid from the reservoir through the spigot by manually adjusting the spigot; a vacuum recovery tank; an AC vacuum motor head assembly and a DC vacuum motor head assembly manually and interchangeably fluidly connectable to the vacuum recovery tank; and a DC power supply assembly. In another aspect of the invention, a portable floor care system with manually interchangeable AC and DC vacuum motor head assemblies for use in cleaning hard surface flooring may include a reservoir assembly including: a reservoir defining an interior space operable to hold a cleaning liquid; a wheeled chassis; and a spigot fluidly connected to the reservoir interior space, the spigot manually adjustable through a range between a fully open position and a fully closed position, whereby when the reservoir contains a cleaning liquid, a user may dispense and regulate the flow of the cleaning liquid from the reservoir through the spigot by manually adjusting the spigot. The portable floor care system may further include: a vacuum recovery tank manually and removably positionable on the reservoir assembly; an AC vacuum motor head assembly and a DC vacuum motor head assembly interchangeably manually and removably positionable on the vacuum recovery tank in fluid communication with the vacuum recovery tank; and a DC power supply assembly manually and removably positionable on the reservoir assembly.