Patent ID: 7388351

Claim:
A capacity equalizing apparatus for secondary batteries comprising: an assembled battery having n battery blocks (n is a positive integer of 2 or more), each battery block comprising one or multiple secondary batteries and said battery blocks being connected in series; n discharge devices, each connected across the positive and negative electrode terminals of each of said battery blocks, for discharging said secondary batteries inside said respective battery blocks; and a controller for individually controlling said discharge devices, wherein said controller has a first control section to which said battery blocks are electrically connected, at least one transmission device having input and output terminals insulated from each other, and a second control section electrically insulated from said first control section by said at least one transmission device, wherein said second control section generates serial data for controlling said n discharge devices and sends said serial data to said first control section via said at least one transmission device, and wherein said first control section includes a serial input/parallel output register for generating, in parallel, n data bits corresponding to said n discharge devices using said serial data.