A charge circuit having multi charge stages for charging at least one
battery includes: a first current generating circuit for generating a
first charge power having a first charge current in pulse form with a
first frequency and a first charge voltage to charge the at least one
battery; a voltage generating circuit connected to the first current
generating circuit for controlling the first charge power having a first
charge current in pulse form with a first frequency and a first charge
voltage; a voltage control circuit connected to the voltage generating
circuit for generating a first constant voltage and/or a second constant
voltage; and a second current generating circuit connected to the voltage
generating circuit for generating a variant power comprising a variant
current in pulse form with a second frequency wherein a charge voltage
included in the variant power varies with the second frequency.