BATTERY-OPERATED BLOWER FILTER SYSTEM FOR USE IN POTENTIALLY EXPLOSIVE AREAS

A blower filter system includes a blower unit (11), an electric motor (24) for driving a blower impeller, a control unit (27) for controlling the electric motor, contacts (22, 23) for connecting to a battery pack, and a battery pack (10) with secondary cells (12) with high energy density and contacts (22, 23) for connecting to the blower unit. The blower unit (11) can be detachably coupled to the battery pack (10). The battery pack is electrically connected to the blower unit via the contacts. The battery pack (10) has protective circuits including electronic components (15, 16, 17, 18, 19, 20, 21, 31) to electrically switch off at least one of the plurality of secondary cells (12) of the battery pack if excessive currents and/or excessive temperatures occur. The battery pack (10) and the blower unit (11) are each at least partially cast in a casting compound.