A power supply device is provided for a human-powered vehicle. The power supply device comprises a base, a first electrical port, a second electrical port and a third electrical port. The first electrical port is provided to the base. The first electrical port has a first connection configuration. The second electrical port is provided to the base, and having a second connection configuration. The third electrical port is provided to the base, and having a third connection configuration. The first connection configuration, the second connection configuration and the third connection configuration have a same shape.