A method of determining a status of a battery operated drug infusing device including a controller, a current sensor, a motor and a pump driven by the motor, the method comprising: measuring an initial input energy level; determining whether the initial input energy level is below a minimum threshold, above a maximum threshold, or represents a steady input energy state between the minimum and maximum thresholds; when the initial input energy level is above the maximum threshold, triggering an alarm; when the initial input energy level is below the minimum threshold, determining whether the initial input energy level remains below the minimum threshold for a predetermined period of time, and if so, triggering an alarm; when the initial input energy level is determined to be at the steady input energy state: establishing the steady input energy state as a baseline power level; and controlling the motor based on a performance of the motor as determined by: measuring an input parameter of the motor, the input parameter including at least a magnitude of a current input to the motor, and ascertaining a status of the device by integrating a magnitude of said current input over a time corresponding to said current input to the motor and comparing the integrated current input over time with the baseline power level. measuring an initial input energy level; determining whether the initial input energy level is below a minimum threshold, above a maximum threshold, or represents a steady input energy state between the minimum and maximum thresholds; when the initial input energy level is above the maximum threshold, triggering an alarm; when the initial input energy level is below the minimum threshold, determining whether the initial input energy level remains below the minimum threshold for a predetermined period of time, and if so, triggering an alarm; when the initial input energy level is determined to be at the steady input energy state: establishing the steady input energy state as a baseline power level; and controlling the motor based on a performance of the motor as determined by: measuring an input parameter of the motor, the input parameter including at least a magnitude of a current input to the motor, and ascertaining a status of the device by integrating a magnitude of said current input over a time corresponding to said current input to the motor and comparing the integrated current input over time with the baseline power level. establishing the steady input energy state as a baseline power level; and controlling the motor based on a performance of the motor as determined by: measuring an input parameter of the motor, the input parameter including at least a magnitude of a current input to the motor, and ascertaining a status of the device by integrating a magnitude of said current input over a time corresponding to said current input to the motor and comparing the integrated current input over time with the baseline power level. measuring an input parameter of the motor, the input parameter including at least a magnitude of a current input to the motor, and ascertaining a status of the device by integrating a magnitude of said current input over a time corresponding to said current input to the motor and comparing the integrated current input over time with the baseline power level.