Abstract: A battery charger comprising input terminals for connection to an AC source, output terminals for connection to a battery to be charged, and a power factor correction (PFC) circuit connected between the input terminals and the output terminals. The PFC circuit comprises a current control loop for regulating an input current drawn from the AC source. The voltage at the output of the PFC circuit is regulated by the voltage of the battery which is reflected back to the PFC circuit. As a result, the battery charger acts as a current source that outputs an output current at the output terminals, and the waveform of the output current is periodic with a frequency twice that of the input current and a ripple of at least 50%.

Abstract: A battery charger comprising input terminals for connection to an AC source supplying an alternating input voltage, output terminals for connection to a battery to be charged, and a power factor correction (PFC) circuit connected between the input terminals and the output terminals. The battery charger monitors the voltage of the battery and operates in a first mode when the voltage is below a threshold. The battery charger then switches to a second mode when the voltage exceeds the threshold. The PFC circuit regulates an input current drawn from the AC source such that the waveform of the input current when operating in the first mode is different to that when operating in the second mode.

Abstract: A battery charger comprising input terminals for connection to an AC source supplying an alternating input voltage, output terminals for connection to a battery to be charged, and a PFC circuit connected between the input terminals and the output terminals. The power factor correction (PFC) circuit regulates an input current drawn from the AC source such that the input current has a waveform selected from a sine wave with third harmonic injection, a clipped sine wave and a trapezoidal wave. The battery charger then generates an output current at the output terminals, the output current having a waveform defined by the multiplication of the input current and the input voltage.