Patent ID: 8310204

Claim:
A charge equalization apparatus for a series-connected battery string, comprising: a battery string comprised of k batteries connected in series; a battery string of m which is one portion of the battery string of k batteries, wherein the battery string of m has m battery cells including an nth battery cell connected in series; an automatic PWM generating means connected in parallel to each of the batteries comprising the battery string; and a charge equalizer connected in parallel to each of the batteries comprising the battery string, wherein: 3≦m≦k; and each automatic PWM generating means comprises: a comparator and a PWM generator automatically generating a PWM signal in response to an output of the comparator, the comparator generates the output by comparing a potential of the nth battery cell with an average potential of the battery string of m, and the charge equalizer is automatically controlled to charge or discharge the nth battery cell according to the PWM signal automatically generated by the PWM generator.