Abstract: A power tool system includes a power tool having a tool housing and a load disposed in the tool housing. The tool housing includes a battery pack receptacle having a set of tool terminals. The power tool system includes a set of battery packs. Each battery pack includes a battery pack housing operably connectable to the battery pack receptacle through a battery pack interface disposed on the battery pack housing, a set of battery cells disposed in the battery pack housing, and a set of battery pack terminals electrically connectable to the set of tool terminals and electrically connected to the set of battery cells. Each battery pack in the set of battery packs has a same nominal voltage and defines a common interface and at least a portion of the set of battery packs defines a total volume in a range of approximately 150 cm3 to 1300 cm3.