Motorola Solutions, Inc.
DETERMINING AVAILABLE BATTERY CURRENT IN A PORTABLE ELECTRONIC DEVICE

Abstract:

Systems and methods for determining available current for a battery in a portable electronic device. One method includes, in response to determining that a received current level of an auxiliary supply rail is equal to or below a predetermined threshold, acquiring a plurality of unloaded voltages for the battery and calculating an unloaded voltage based on the unloaded voltages. The method includes activating a switchable load coupled between the battery and ground, acquiring a plurality of loaded voltages for the battery, and calculating a loaded voltage based on the loaded voltages. The method includes calculating an impedance for the battery based on the unloaded and loaded voltages and an impedance for the switchable load. The method includes determining a current budget based on the impedance, a minimum operating voltage, and a maximum allowable current draw, and adjusting an operating parameter of the portable electronic device based on the current budget.