Method and apparatus for predicting end of battery life

Abstract

A powering subassembly for a portable electronic device includes a main battery, a converter, a backup battery, and a controller. The main battery provides a main voltage and the backup battery can provide a backup voltage. The converter receives the main voltage and increases it to at least one operating voltage. The controller receives the operating voltage from the converter, monitors the voltage of the main battery, and compares the monitored voltage to a main battery low voltage threshold. The controller transmits a disconnect signal to decouple the main battery from the converter if the monitored voltage from the main battery is less than the main battery low voltage threshold. The controller transmits a connection signal to couple the backup battery to the converter if the monitored voltage is less than the main battery low voltage threshold. The backup battery provides the power for a predetermined minimum amount of time.

1 . A method of providing backup power to a portable electronic device having a main battery and a backup battery, the method comprising:
 detecting whether the main battery has been inserted into the portable electronic device and transmitting a detection signal to a controller if the main battery is detected;   after the main battery has been detected, coupling a voltage from the main battery to a power converter;   providing an operating voltage from the power converter to the controller;   charging the backup battery utilizing a signal transmitted from the controller, so as to charge the backup battery by the main battery;   monitoring a battery level of the backup battery and disabling the charging of the backup battery if the charging level of the backup battery has been exceeded;   monitoring a battery level of the main battery and generating a first signal to cause the main battery to be disconnected if the battery level of the main battery is less than a low-battery threshold value; and   generating a second signal to cause the backup battery to provide power for the portable electronic device.   
     
     
         2 . The method of  claim 1 , wherein charging of the backup battery is automatically initiated upon detection of the main battery. 
     
     
         3 . The method of  claim 1 , wherein the backup battery provides power for operating the portable electronic device with full feature functionality for a period of at least 24 hours. 
     
     
         4 . The method of  claim 1 , wherein the low-battery threshold value is less than 1.0 volt. 
     
     
         5 . The method of  claim 1 , wherein the battery level of the main battery and the low-battery threshold are both values of a current supplied by the main battery. 
     
     
         6 . The method of  claim 1 , wherein the generation of the first signal and the second signal occur substantially simultaneously. 
     
     
         7 . The method of  claim 1 , wherein the portable electronic device is an insulin pump. 
     
     
         8 . The method of  claim 1 , wherein a capacitor is coupled between the main battery and the power converter, the capacitor receives the voltage from the main battery, and provides the voltage to the power converter. 
     
     
         9 . A program code storage device, comprising:
 program code storage media; and   machine-readable program code, stored on the program code storage media, the machine-readable program code including instructions, which when executed cause a controller for a portable electronic device having a main battery and a backup battery to:   receive a main battery detection signal indicating that the main battery of the portable electronic device is present within a powering circuit of the portable electronic device;   receive an operating level of the backup battery of the portable electronic device;   upon receipt of the main battery detection signal, transmit a signal to a backup battery charging circuit to charge the backup battery by the main battery if the backup battery's operating level is below a backup battery charging threshold;   receive a charging level of the backup battery and stop transmitting the signal to the charging circuit if the charging level of the backup battery is above the charging threshold;   receive a main battery voltage reading and compare the main battery voltage reading against a main battery low voltage threshold;   if the main battery voltage reading is less than or equal to the main battery low voltage threshold, transmit a main battery disconnect signal to a switching device to disconnect the main battery from providing power to the controller; and   transmit a backup battery connect signal to a switching device to connect the backup battery of the portable electronic device to provide power to the controller.   
     
     
         10 . The program code storage device of  claim 9 , including instructions, which when executed, cause the controller to transmit a message to a display of the portable electronic device indicating a minimum time for which the backup battery can provide power for the portable electronic device. 
     
     
         11 . The program code storage device of  claim 9 , including instructions, which when executed, cause the controller to automatically transmit the signal to the backup battery charging circuit to charge the backup battery by the main battery if the backup battery's operating level is below the backup battery charging threshold. 
     
     
         12 . A powering subassembly for a portable insulin pump comprising:
 a main battery to provide a main voltage to the insulin pump;   a converter to receive the main voltage and to increase the main voltage to at least one operating voltage;   a capacitor coupled between the main battery and the converter, wherein the capacitor is charged up by the main battery and provides a smoother main voltage to the converter;   a backup battery configured to be charged by the main battery and to provide a backup voltage to the insulin pump; and   a controller to receive the operating voltage from the converter, to monitor a voltage level of the main battery, to compare the monitored voltage level of the main battery to a main battery low voltage threshold, to transmit a disconnect signal to prevent the main battery from providing the main voltage to the converter if the monitored voltage level is less than or equal to the main battery low voltage threshold, to transmit a connection signal to the backup battery to cause the backup battery to provide a backup voltage to the converter, and to receive an operating level of the backup battery and transmit a signal to a charging device to charge the backup battery by the main battery if the operating level of the backup battery is below a charging threshold.   
     
     
         13 . The powering subassembly according to  claim 12 , wherein the backup battery provides power for operating the insulin pump with full feature functionality for a period of at least 24 hours. 
     
     
         14 . The powering subassembly according to  claim 12 , wherein, if the operating level of the backup battery is below the charging threshold, the controller automatically transmits the signal to the charging device to charge the backup battery by the main battery. 
     
     
         15 . The powering subassembly according to  claim 12 , further including a switching device to uncouple the main battery from a reference ground after receiving the disconnect signal. 
     
     
         16 . The powering subassembly according to  claim 12 , wherein the controller monitors a charging level of the backup battery and discontinues transmission of the signal to the charging device if the charging level of the backup battery is above the charging threshold. 
     
     
         17 . The powering subassembly of  claim 12 , wherein the main battery low voltage threshold is less than 0.8 volt. 
     
     
         18 . The powering subassembly according to  claim 12 , wherein at least 95% of the main battery energy is utilized before the main battery reaches a low voltage threshold. 
     
     
         19 . The powering subassembly according to  claim 12 , wherein the converter provides other operating voltages to a pump, a display, and a second processor, the second processor not being the controller. 
     
     
         20 . A portable insulin pump, comprising:
 a display to provide messages to a user; and   a powering subassembly, the powering subassembly including:   a main battery to provide a main voltage to the portable insulin pump;   a backup battery configured to be charged by the main battery and to provide a backup voltage to the portable insulin pump;   a capacitor, coupled to one of the main battery and the backup battery, and capable of being coupled to both the main battery and the backup battery, to receive either the main voltage or the backup voltage, and to transfer the received voltage;   a converter to receive the received voltage from the capacitor and to generate at least one operating voltage; and   a controller to receive the at least one operating voltage from the converter, to monitor the main voltage of the main battery, to compare the monitored level of the main battery to a main battery low voltage threshold, to transmit a disconnect signal to prevent the main voltage from the main battery from being coupled to the capacitor if the monitored level of the main battery is less than or equal to the main battery low voltage threshold, to transmit a signal to a charging device to charge the backup battery by the main battery if the backup voltage of the backup battery is below a charging threshold, and to transmit a connect signal to couple the backup voltage from the backup battery to the capacitor if the monitored level of the main battery is less than or equal to the main battery low voltage threshold.   
     
     
         21 . The insulin pump of  claim 20 , wherein the backup battery provides power for operating the insulin pump with full feature functionality for a period of at least 24 hours. 
     
     
         22 . The insulin pump of  claim 20 , wherein, if the operating level of the backup battery is below the charging threshold, the controller automatically transmits the signal to the charging device to charge the backup battery by the main battery. 
     
     
         23 . The insulin pump of  claim 20 , wherein the converter provides an operating voltage for the display. 
     
     
         24 . The insulin pump of  claim 20 , wherein the main battery can be a removable rechargeable battery which can be recharged by household current. 
     
     
         25 . The insulin pump of  claim 20 , wherein the main battery low voltage threshold is less than 1.0 volt. 
     
     
         26 . The insulin pump of  claim 20 , wherein at least 95% of the main battery energy is utilized before the main battery reaches a low voltage threshold.