An alkaline dry battery includes a bottomed cylindrical battery case; a positive electrode packed in the battery case and including n hollow cylindrical pellets; a negative electrode disposed in a hollow portion of the pellets; a separator interposed between the positive electrode and the negative electrode; and an alkaline electrolytic solution. The positive electrode includes manganese dioxide and a conductive agent, n is an integer of 1 or more, and an average density of manganese dioxide of the positive electrode is 2.80 to 3.00 g/cm.sup.3. The density d.sub.c of manganese dioxide in the center portion in the height direction of the positive electrode is 98% or less of an average value d.sub.e of density of manganese dioxide in each of both end portions.

A nickel-hydrogen secondary battery includes: an outer can; a sealing body including a positive electrode terminal, the sealing body sealing an opening of the outer can; an electrode group formed by placing a positive electrode and a negative electrode on top of each other with a separator therebetween and spirally winding the positive electrode and the negative electrode, the electrode group housed in the outer can along with an alkaline electrolyte; a positive electrode current collector connected to positive electrode connection edge portion protruding from one end surface of the electrode group; and a current collecting lead connecting the positive electrode current collector and the sealing body, wherein a relationship between a deformation resistance A of a material a and a deformation resistance B of a material b satisfies a relationship of A<B, wherein the material a is a material of the current collecting lead, and the material b is a material of the positive electrode current collector.

An alkaline dry battery includes a bottomed cylindrical battery case; a positive electrode packed in the battery case and including n hollow cylindrical pellets; a negative electrode disposed in a hollow portion of the pellets; a separator interposed between the positive electrode and the negative electrode; and an alkaline electrolytic solution. The positive electrode includes manganese dioxide and a conductive agent, n is an integer of 1 or more, and an average density of manganese dioxide of the positive electrode is 2.80 to 3.00 g/cm.sup.3. The density d.sub.c of manganese dioxide in the center portion in the height direction of the positive electrode is 98% or less of an average value d.sub.e of density of manganese dioxide in each of both end portions.

A battery pack has bus bars at one end, freeing the other end of the battery pack for cooling or other arrangements. A plurality of battery cells has first terminals of the battery cells at first ends of the battery cells. Portions of second terminals of the battery cells are at the first ends of the battery cells. The first ends of the battery cells are in a coplanar arrangement. A plurality of bus bars is assembled proximate to the first ends of the battery cells. The bus bars are coupled to the first terminals and the second terminals of the battery cells at the first ends of the battery cells to place the battery cells in one of a series connection, a parallel connection or a series and parallel connection.

A battery pack has bus bars at one end, freeing the other end of the battery pack for cooling or other arrangements. A plurality of battery cells has first terminals of the battery cells at first ends of the battery cells. Portions of second terminals of the battery cells are at the first ends of the battery cells. The first ends of the battery cells are in a coplanar arrangement. A plurality of bus bars is assembled proximate to the first ends of the battery cells. The bus bars are coupled to the first terminals and the second terminals of the battery cells at the first ends of the battery cells to place the battery cells in one of a series connection, a parallel connection or a series and parallel connection.

A nickel-hydrogen secondary battery includes: an outer can; a sealing body including a positive electrode terminal, the sealing body sealing an opening of the outer can; an electrode group formed by placing a positive electrode and a negative electrode on top of each other with a separator therebetween and spirally winding the positive electrode and the negative electrode, the electrode group housed in the outer can along with an alkaline electrolyte; a positive electrode current collector connected to positive electrode connection edge portion protruding from one end surface of the electrode group; and a current collecting lead connecting the positive electrode current collector and the sealing body, wherein a relationship between a deformation resistance A of a material a and a deformation resistance B of a material b satisfies a relationship of A<B, wherein the material a is a material of the current collecting lead, and the material b is a material of the positive electrode current collector.

A hydrogen-absorbing alloy is provided in which an X-ray diffraction image generated by CuK rays has at least one peak selected from (1) peak Psp1 at 2=32.250.15, (2) peak Psp2 at 2=33.550.15, and (3) peak Psp3 at 2=37.270.15.

A battery pack has bus bars at one end, freeing the other end of the battery pack for cooling or other arrangements. A plurality of battery cells has first terminals of the battery cells at first ends of the battery cells. Portions of second terminals of the battery cells are at the first ends of the battery cells. The first ends of the battery cells are in a coplanar arrangement. A plurality of bus bars is assembled proximate to the first ends of the battery cells. The bus bars are coupled to the first terminals and the second terminals of the battery cells at the first ends of the battery cells to place the battery cells in one of a series connection, a parallel connection or a series and parallel connection.