Battery pack for an electric power tool

A battery pack for an electric power tool, the battery pack comprising:

• at least one cell arrangement with a plurality of individual battery cells;
• an upper cell holder and a lower cell holder, wherein said battery cells are secured between the upper cell holder and the lower cell holder and wherein said battery cells, the upper cell holder and the lower cell holder together form a parallelepipedal cell container;
• the upper and lower cell holders each having a first longitudinal side, a second longitudinal side, and narrow sides;
• wherein a predetermined total number of said battery cells is arranged upright adjacent to one another for forming the cell container such that cell axes of said battery cells are approximately perpendicular to a common reference plane;
• cell connectors electrically conductingly connecting cell ends of said battery cells;
• wherein said battery cells of said cell container comprise a core cell and neighboring cells surrounding said core cell, wherein said neighboring cells each are radially spaced from said core cell so that said core cell and said neighboring cells do not contact each other, respectively, and an enlarged free radial space is provided around said core cell compared to an arrangement in which said neighboring cells are contacting said core cell;
• wherein said neighboring cells are radially spaced at different radial spacings relative to said core cell, respectively, so that points of intersection of said cell axes of all of said neighboring cells with said reference plane are positioned on a closed elliptical curve having a major axis and a minor axis, wherein the major axis is greater than the minor axis, wherein said core cell is positioned at a point of intersection of the minor axis and the major axis and wherein none of said neighboring cells is aligned with said core cell on the minor axis or the major axis;
• wherein said enlarged free radial space reduces a heat transmission from said neighboring cells surrounding said core cell onto said core cell, respectively;
• wherein the major axis extends approximately parallel to the first and second longitudinal sides of the cell holders and the minor axis extends approximately parallel to the narrow sides of the cell holders;
• wherein a number of said neighboring cells is greater than one third of said total number of said battery cells of said cell container;
• wherein said battery cells of said cell container comprise terminal cells that are arranged in two terminal rows opposite each other, wherein said neighboring cells are positioned between said two terminal rows of said terminal cells;
• wherein center points of said terminal cells in each of said two terminal rows are positioned on a straight line, respectively, wherein said straight line extends perpendicular to said major axis, respectively;
• wherein said core cell, said neighboring cells, and said terminal cells each have the same geometric shape and the same geometric dimensions.