A converter device, comprising: an inductor having a first end and a second end; and a switching circuit connected to the inductor, comprising a first switch configured to control a connection between the first end of the inductor and a battery which is configured to be connected to the converter a second switch (SW2; SW Hi) configured to control a connection between the second end of the inductor and a current output end configured to output a current generated through the inductor from the battery; a third switch configured to control a connection between the second end of the inductor and a voltage output end configured to output a voltage generated from the battery; and a fourth switch configured to control a connection between the second end of the inductor and a voltage input end configured to receive a voltage to charge the battery, a fifth switch configured to control a connection between the first end of the inductor and a ground; wherein the switching circuit further comprises a freewheeling switch configured to control a connection between the first end of the inductor and the second end of the inductor, a controller to control switching operations of the switching circuit; characterised in that the second switch (SW2; SW Hi) includes an H-bridge connected to the second end of the inductor and configured to control a direction in which the current is output to the current output end, wherein the controller is configured to control the freewheeling switch to be on during a first interval in a timeslot in which the current is output and off during a second interval in the timeslot, and to control a portion of switches of the H-bridge and the fifth switch to be off during the first interval in the timeslot and on during the second interval in the timeslot, and wherein the current to be output from the current output end is in a form of pulse wave. an inductor having a first end and a second end; and a switching circuit connected to the inductor, comprising a first switch configured to control a connection between the first end of the inductor and a battery which is configured to be connected to the converter a second switch (SW2; SW Hi) configured to control a connection between the second end of the inductor and a current output end configured to output a current generated through the inductor from the battery; a third switch configured to control a connection between the second end of the inductor and a voltage output end configured to output a voltage generated from the battery; and a fourth switch configured to control a connection between the second end of the inductor and a voltage input end configured to receive a voltage to charge the battery, a fifth switch configured to control a connection between the first end of the inductor and a ground; a first switch configured to control a connection between the first end of the inductor and a battery which is configured to be connected to the converter a second switch (SW2; SW Hi) configured to control a connection between the second end of the inductor and a current output end configured to output a current generated through the inductor from the battery; a third switch configured to control a connection between the second end of the inductor and a voltage output end configured to output a voltage generated from the battery; and a fourth switch configured to control a connection between the second end of the inductor and a voltage input end configured to receive a voltage to charge the battery, a fifth switch configured to control a connection between the first end of the inductor and a ground; wherein the switching circuit further comprises a freewheeling switch configured to control a connection between the first end of the inductor and the second end of the inductor, a controller to control switching operations of the switching circuit; characterised in that the second switch (SW2; SW Hi) includes an H-bridge connected to the second end of the inductor and configured to control a direction in which the current is output to the current output end, wherein the controller is configured to control the freewheeling switch to be on during a first interval in a timeslot in which the current is output and off during a second interval in the timeslot, and to control a portion of switches of the H-bridge and the fifth switch to be off during the first interval in the timeslot and on during the second interval in the timeslot, and wherein the current to be output from the current output end is in a form of pulse wave.