The present technology relates to systems and methods for rapidly charging a battery of a device when the device is attached to an AC adapter. Some embodiments of the present disclosure describe an activation circuit in an AC adaptor and a detection circuit in a downstream device that cooperatively ensure optimal power delivery. Some embodiments of the present disclosure describe a device with a system load, a battery, and a control circuit, wherein the control circuit is configured to provide the battery with a charging current of Ibat=Imax−Isys when the device is in a USB compliant mode of operation and a charging current of Ibat=Imax when the device is connected to an AC adapter.