A battery cell, a battery, and an electrical apparatus are provided. The battery cell includes an electrode assembly and a casing. The electrode assembly includes a main body portion and a first tab extending from one end of the main body portion in a first direction. The casing defines an accommodation cavity in which the electrode assembly is disposed. The casing further includes a first through hole and a second through hole. A portion of the accommodation cavity on a side of the first tab communicates with the first through hole, and a portion of the accommodation cavity on a side of the main body portion opposite the first tab communicates with the second through hole, the first through hole being configured for electrolyte injection. In an axial direction of the first through hole, neither the first tab nor the main body portion overlaps the first through hole.