A circuit for controlling a charging parameter provided to a rechargeable battery. The circuit includes a power control circuit configured to provide a power control signal representative of a power output level of a DC source, and a control signal generating circuit configured to reduce the charging parameter provided to the battery if the power output level exceeds a predetermined power threshold level. An electronic device having such a circuit and a method is also provided. The circuit may be used with a DC source that supplies power to recharge a rechargeable battery. The DC source may have a non-fixed output voltage level such as from a controllable DC source or a variable DC source.