Certain aspects of the present disclosure relate to methods and apparatus for limiting the power drawn by a battery charger based on monitoring of the input voltage and input current supplied to the battery charger from a power supply. In certain aspects, a method generally includes sensing an output voltage of the power supply, wherein the output voltage of the power supply is variable. The method further includes sensing an output current of the power supply. The method further includes providing the output voltage and output current to a battery charger. The method further includes generating a control signal indicative of a scaling of the output current based on a scaling factor, wherein the scaling factor is based on the output voltage. The method further includes providing the control signal to the battery charger to control the output current supplied by the power supply to the battery charger.