A battery includes a case, an internal terminal, an external terminal, and an insulator. The internal terminal includes an internal terminal base and a shaft. The internal terminal base is disposed inside the case, with the insulator interposed between the case and the internal terminal base. The external terminal includes an external terminal base and a boss. The external terminal base is disposed outside the case, with the insulator interposed between the external terminal base and the case. The boss extends from the external terminal base. The boss receives the shaft of the internal terminal therethrough. The boss is pressure-welded to the shaft of the internal terminal.