Patent ID: 9559538
Date: 2017-01-31
CPC Classifications: H02J

Claim:
1. A battery charging system for a mobile device, comprising: an adapter that receives power from a power source and generates an adapter output voltage, the adapter output voltage being outputted to vary within a reference voltage range that is substantially narrow and includes a preferred adapter voltage, the preferred adapter voltage being associated with a preferred battery charging condition under which the battery is driven and charged up with a preferred charging power; a battery charger, coupled to the adapter, the battery charger generating a battery charging current that is monitored to allow the reference voltage range to track a variation of load condition at the output of the adapter; and a battery, coupled to the battery charger, the battery being driven and charged up by the battery charging current when the mobile device is coupled to the power source, power stored in the battery being further used to drive normal operation of the mobile device when the mobile device is decoupled from the power source; wherein the preferred battery charging condition is determined when a variation of the battery charging current is sensed to drop during a course of gradually reducing the adapter output voltage from an initial voltage based on a constant voltage step.