Abstract: A charge and discharge device (10) includes: a battery unit (110) in which m (m is an integer of 3 or more) battery cells (112) that are connected in series are grouped into plural groups (114) including n (n is an integer equal to or larger than 2 and smaller than m) battery cells (112) that are continuously arranged and a part of the battery cells (112) that belong to a certain group is shared by a different group; a cell balance unit (120) that is provided for each group (114) and uniformizes voltages of the battery cells (112) that belong to the group (114); and a control unit (130) that stops the operation of the cell balance unit (120), when a voltage difference of the battery cells (112) that belong to an arbitrary one of the groups (114) is within a predetermined value, and when a total average voltage in all the battery cells (112) and a partial average voltage which is an average voltage of the battery cells (112) that belong to the arbitrary group (114) satisfy a specific condition, the cell balanc