The embodiments of this application provide a battery cell, a battery, an electrical device, and a battery cell manufacturing method and device, which pertains to the technical field of batteries. The battery cell includes an electrode assembly, a housing, an end cover assembly, and a support piece. The electrode assembly includes a main body and tabs. The housing has an opening and is used to accommodate the electrode assembly. The end cover assembly is used to cover the opening. The support piece is located between the main body and the end cover assembly, the tabs are bent around the support piece, and the support piece is configured to prevent the main body from moving along a direction facing the end cover assembly.