A wearable device according to an embodiment disclosed herein may include: a housing forming at least a part of an exterior of the wearable device; a battery disposed in the housing and including a positive electrode terminal and a negative electrode terminal; a connection terminal part, at least a part of which is exposed through at least a part of the housing and including a first terminal and a second terminal; a bridge circuit configured to, based on a polarity of a first voltage applied to the first terminal, electrically connect the first terminal to one of the positive electrode terminal and the negative electrode terminal having polarity corresponding to the polarity of the first voltage, and based on a polarity of a second voltage applied to the second terminal, electrically connect the second terminal to one of the positive electrode terminal and the negative electrode terminal having polarity corresponding to the polarity of the second voltage; a sensor module configured to obtain bio-information; and a switch circuit configured to selectively connect the connection terminal part with the bridge circuit and the sensor module.