Patent ID: 7592780

Claim:
A battery charging apparatus comprising: a plurality of input terminals receiving an Alternating Current (AC) voltage from an AC power; a first rectifier smoothing circuit for rectifying and smoothing the AC voltage; a switching circuit connected across a plurality of output terminals of the first rectifier smoothing circuit to provide pulse signal; a second rectifier smoothing circuit for rectifying and smoothing the pulse signals; an output voltage of the second rectifier smoothing circuit being applied to a battery to be charged; a charge current control unit that detects a charging current flowing through the battery and controls the charging current in accordance with a charging current set value; a first voltage detecting unit for detecting a voltage across the battery; a second voltage detecting unit for detecting an input voltage which is applied to the switching unit; and a microcomputer which sets a first charging current set value when the input voltage applied to the switching circuit is greater than a predetermined value and sets a second charging current set value which is smaller than the first charging current value when the input voltage of the switching circuit becomes smaller than the predetermined value.