Abstract: The present invention relates to a battery charger for charging a battery (10), said battery charger comprising an AC/DC power supply means (1), a pulse width modulation controlled DC/DC converter (2) and a control unit (3) that is connected to the AC/DC power supply means (1) and the PWM-controlled DC/DC converter (2). The battery charger has a maximum output power while avoiding to blow up small battery packs if the control unit (3) is adapted to measure at least a voltage and a current at terminals of the battery (10) to be charged, calculate a power at the battery (10), compare the calculated power and the nominal maximum power of the AC/DC power supply means (1), and transmit a signal to the PWM-controlled DC/DC converter (2) to adjust a charging current supplied to the battery (10) based on the comparison result. A temperature at the battery can also be measured.

Abstract: The present invention relates to a battery charger for charging a battery (10), said battery charger comprising an AC/DC power supply means (1), a pulse width modulation controlled DC/DC converter (2) and a control unit (3) that is connected to the AC/DC power supply means (1) and the PWM-controlled DC/DC converter (2). The battery charger has a maximum output power while avoiding to blow up small battery packs if the control unit (3) is adapted to measure at least a voltage and a current at terminals of the battery (10) to be charged, calculate a power at the battery (10), compare the calculated power and the nominal maximum power of the AC/DC power supply means (1), and transmit a signal to the PWM-controlled DC/DC converter (2) to adjust a charging current supplied to the battery (10) based on the comparison result. A temperature at the battery can also be measured.