Serial charging and discharging system, and method of disconnecting cell in serial charging and discharging system

A method of disconnecting a cell in a serial charging and discharging system, comprising the steps of:

• charging a cell with a first switch and a second switch being turned ON, and a third switch being turned OFF;
• turning OFF the first switch;
• turning ON the third switch;
• and
• disconnecting the cell from the step of charging with the second switch being turned OFF.

A serial charging and discharging system, comprising:

• a cell connected in series to a power source for charging and discharging the cell;
• a diode provided upstream of the cell;
• a first switch connected in parallel to the diode;
• a second switch connected in series between the diode and the cell;
• a bypass circuit which bypasses the upstream of the diode and the downstream of the cell;
• a third switch connected to the bypass circuit;
• and
• a controller which controls the make and break of the first switch, the second switch, and the third switch, wherein
• the controller controls respective switches so as to turn ON the first switch and the second switch, and turn OFF the third switch when charging the cell, and
• the controller controls respective switches so as to turn OFF the first switch, subsequently turn ON the third switch, and then turn OFF the second switch when finishing the charging of the cell.