Method and apparatus for charging a battery of an electronic device using an intelligent external charger

• US 5,734,252 A
• Filed: 12/20/1996
• Issued: 03/31/1998
• Est. Priority Date: 12/20/1996
• Status: Expired due to Fees

• Current Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Wakefield, Ivan Nelson, Griffin, Lee Daniel
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): SHIN, KYUNG E
• Application Number:
  US08/770,860
• Time in Patent Office: 466 Days
• Field of Search: 320/2, 320/15, 320/5, 320/48, 320/27, 320/28, 320/29, 320/30, 320/47
• US Class Current: 320/124
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/0071 with a programmable schedule

Abstract

An apparatus and method for disabling the internal battery charging algorithm of an electric device when connected to a smart battery charger having its own internal controller and charging algorithm. The controller of the external battery charger varies the output of the charger to provide the battery with a current source that predictably varies in voltage or represents a digital signal at a preset data rate. The internal controller of the electronic device recognizes the varying nature of the supplied direct current and disables its own internal battery charging algorithm. The charging algorithm of the external battery charger thus independently controls the charging of the electronic device internal battery.

Claims

1. A system for overriding an internal controller recharging algorithm of an electronic device when the electronic device is connected to an external battery charger having an independent controller comprising:

means for producing a varying voltage having a defined duty cycle and cycle period on a charging current by the external battery charger;

means for detecting the varying voltage on the charging current by the electronic device; and

means for disabling the internal controller recharging algorithm in response to detection of the varying voltage.

2. The system recited in claim 1, wherein the means for producing the varying voltage on the charging current comprises a switch controlled by the external battery charger which turns the charging current on and off.

3. The system recited in claim 1, wherein the means for detecting the varying voltage on the charging current comprises an analog to digital converter for sampling voltage levels of the charging current.

4. The system recited in claim 1, wherein the means for disabling the internal controller comprises the internal controller disabling the recharging algorithm in response to recognition by the controller of the sampled voltage levels communicated from the analog to digital converter as varying in voltage.

5. A system for overriding an internal controller recharging algorithm of an electronic device when the electronic device is connected to an external battery charger having an independent controller comprising:

a direct current output of the external battery charger for connecting to a direct current input of the electronic device, the external battery charger producing a repetitive digital signal on the direct current output;

a means for detecting the repetitive digital signal on the direct current input; and

a means for disabling the internal controller recharging algorithm in response to detection of the repetitive digital signal on the direct current input.

6. The system recited in claim 5, wherein the means for detecting the repetitive digital signal on the direct current input comprises an analog to digital converter for sampling voltage levels at the direct current input.

7. The system recited in claim 6, wherein the means for detecting the repetitive digital signal further includes the analog to digital converter communicating the sampled voltage levels to the internal controller, the internal controller recognizing the sampled voltage levels as the repetitive signal, and the internal controller disabling the internal controller recharging algorithm in response to recognition of the repetitive digital signal.

8. An system for overriding an internal controller recharging algorithm of an electronic device when the electronic device is connected to an external battery charger having an independent controller comprising:

a direct current output of an external battery charger for applying a repetitive digital signal to a direct current input of the electronic device;

an analog to digital converter for generating a sampled voltage level of the voltage level applied to the direct current input; and

an internal controller recognizing the sampled voltage level as the repetitive digital signal and disabling the recharging algorithm in response to the recognition.

9. A method for overriding an internal controller recharging algorithm of an electronic device when the electronic device is connected to an external battery charger having an independent controller comprising the steps of:

connecting an external battery charger to a direct current input of the electronic device to facilitate recharging of an electronic device battery, the external battery charger producing a varying direct current voltage having a defined duty cycle and cycle period;

detecting the varying direct current voltage at the direct current input of the electronic device;

connecting the direct current input to the electronic device battery in response to detection of the varying direct current voltage; and

disabling the internal controller recharging algorithm during recharging of the electronic device battery by the external battery charger in response to detection of the varying direct current voltage.

10. A method for overriding an internal controller recharging algorithm of an electronic device when the electronic device is connected to an external battery charger having an independent controller comprising the steps of:

connecting an external battery charger to a direct current input of the electronic device to facilitate recharging of an electronic device battery, the external battery charger producing a repetitive digital signal;

detecting the repetitive digital signal present at the direct current input of the electronic device;

connecting the direct current input to the electronic device battery in response to detection of the repetitive digital signal; and

disabling the internal controller recharging algorithm of the electronic device during recharging of the electronic device battery by the external battery charger in response to detection of the repetitive digital signal.

11. A system for communicating between an electronic device and an external battery charger comprising:

a charging bus connecting the electronic device to the external battery charger;

a first analog to digital converter located within the electronic device for receiving communication messages over the charging bus;

a first switch located within the electronic device connecting the charging bus to a battery of the electronic device, the first switch for modulating the battery output to send communication messages over the charging bus;

a second analog to digital converter located within the external battery charger for receiving communication messages over the charging bus; and

a second switch located within the external battery charger connecting the charging bus to a charging power supply of the external battery charger, the second switch for modulating the charging power supply output to send communication messages over the charging bus.

12. An apparatus for sending and receiving communication messages over a charging bus comprising:

an analog to digital converter for receiving communication messages over the charging bus;

a switch for connecting the charging bus to a power supply for modulating the power supply output applied to the charging bus; and

a controller for controlling the switch for sending communication messages over the charging bus.