The present application provides a battery and an apparatus. The battery includes: a first-type battery cell group and a second-type battery cell group which are connected in series, wherein the first-type battery cell group is composed of multiple first-type batteries connected in parallel, and the second type battery cell group is composed of at least one second type battery cell connected in parallel; the first-type battery cell and the second-type battery cell are battery cells of different chemical systems, and the volume energy density of the first-type battery cell is less than that of the second-type battery cell; and the capacity Cap1 of the first-type battery cell group is greater than the capacity Cap2 of the second-type battery cell group, in which Cap1 is the sum of the capacities of the corresponding first-type battery cells, and Cap2 is the sum of the capacities of the corresponding second-type battery cells.