Electrical components and vacuums. In some aspects, the invention provides an electrical component including a housing defining a passageway, a motor supported by the housing, the motor being selectively electrically connectable with a power source, a fan connected to the motor and operable to generate an airflow through the passageway, an electrical circuit supported by the housing, the electrical circuit being selectively electrically connectable with the power source, and a power-tool battery electrically connectable with the electrical circuit such that power is selectively transferred between the battery and the electrical circuit, the battery being connectable to the housing. In some aspects, the invention provides a vacuum.