Methods for determining and controlling battery expansion

• US 9,917,335 B2
• Filed: 08/28/2015
• Issued: 03/13/2018
• Est. Priority Date: 08/28/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Jarvis, Daniel W., DeMuro, David M., Dai, Hongli, Malinski, Julian, Marcil, Julien, Lee, Meng Chi, Dinh, Richard Hung Minh, Bhargava, Rishabh, Sterz, Steven D., Mank, Richard M., Manthiri, Soundararajan, Boovaragavan, Vijayasekaran
• Primary Examiner(s): Marks, Jacob
• Application Number:
  US14/838,395
• Publication Number:
  US 20160064780A1
• Time in Patent Office: 928 Days
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: H01M 10/4257 Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/445 in response to gas pressure
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Methods and systems for detecting and compensating for expansion of rechargeable batteries over time. An expansion detector may be coupled to or positioned proximate a rechargeable battery to monitor for expansion thereof. After expansion exceeding a selected threshold is detected, the expansion detector may report the expansion to an associated processing unit. The processing unit may undertake to arrest further rechargeable battery expansion by modifying or changing one or more characteristics of charging and/or discharging circuitry coupled to the rechargeable battery. For example, the processing unit may charge the rechargeable battery at a lower rate or with reduced voltage after detecting expansion.

Claims

1. An electronic device, comprising:

a rechargeable battery within a housing;

a processing unit configured to control an electrical input generated by a power source and provided to the rechargeable battery; and

an expansion detector electrically coupled to the processing unit and comprising a capacitive sensor;

wherein;

the expansion detector sends an expansion signal to the processing unit upon determining that the rechargeable battery has expanded; and

in response to receiving the expansion signal, the processing unit modifies one or more characteristics of the electrical input.

2. The electronic device of claim 1, wherein the capacitive sensor comprises:

a first electrically conductive surface coupled to an external surface of the rechargeable battery; and

a second electrically conductive surface conductively coupled to the first electrically conductive surface.

3. The electronic device of claim 2, wherein the expansion detector is configured to measure a capacitance between the first electrically conductive surface and the second electrically conductive surface.

4. The electronic device of claim 2, wherein the second electrically conductive surface is coupled to the housing.

5. The electronic device of claim 2, wherein the second electrically conductive surface comprises a top surface of the rechargeable battery;

and

the external surface of the rechargeable battery comprises a bottom surface of the rechargeable battery.

6. The electronic device of claim 1, wherein the capacitive sensor comprises:

an array of electrically conductive surfaces, each of which is coupled to an external surface of the rechargeable battery.

7. The electronic device of claim 6, wherein the expansion detector is configured to individually measure a capacitance between each electrically conductive surface of the array of electrically conductive surfaces and a reference surface.

8. The electronic device of claim 1, wherein:

the expansion detector comprises a first electrically conductive plate and a second electrically conductive plate separated by an air gap;

the first electrically conductive plate is coupled to an internal surface of the housing; and

the second electrically conductive plate is coupled to an external surface of the housing.

9. The electronic device of claim 8, wherein the expansion detector is configured to send the expansion signal to the processing unit upon detecting an electrical connection between the first electrically conductive plate and the second electrically conductive plate.

20. The electronic device of claim 1, wherein the capacitive sensor comprises:

a first electrically conductive surface coupled to an external surface of the rechargeable battery;

a second electrically conductive surface; and

an insulator coupled to and separating the first electrically conductive surface and the second electrically conductive surface.

21. The electronic device of claim 20, wherein the insulator comprises a cell of the rechargeable battery.

22. The electronic device of claim 20, wherein the second electrically conductive surface is within the rechargeable battery.

10. A rechargeable battery within a housing of a portable electronic device, the rechargeable battery comprising:

a rechargeable battery module;

a container containing the rechargeable battery module; and

a rechargeable battery expansion detector electrically coupled to a processing unit associated with the portable electronic device, the rechargeable battery expansion detector comprising a capacitive sensor;

wherein;

the rechargeable battery expansion detector sends an expansion signal to the processing unit upon determining that the rechargeable battery has expanded; and

in response to receiving the expansion signal, the processing unit modifies one or more characteristics of an electrical input to the rechargeable battery.

11. The rechargeable battery of claim 10, wherein the capacitive sensor comprises:

a first electrically conductive surface; and

a second electrically conductive surface;

wherein the first electrically conductive surface is coupled to an external surface of the rechargeable battery.

12. The rechargeable battery of claim 11, wherein the rechargeable battery expansion detector is configured to measure a capacitance between the first electrically conductive surface and the second electrically conductive surface.

13. The rechargeable battery of claim 10, wherein the capacitive sensor comprises:

an array of electrically conductive surfaces, wherein each electrically conductive surface of the array of electrically conductive surfaces is coupled to an external surface of the rechargeable battery.

14. The rechargeable battery of claim 11, wherein the second electrically conductive surface is coupled to the housing.

15. The rechargeable battery of claim 13, wherein:

the array of electrically conductive surfaces is a first array of electrically conductive surfaces coupled to a top surface of the rechargeable battery; and

the capacitive sensor further comprises a second array of electrically conductive surfaces coupled to a bottom surface of the rechargeable battery.

16. The rechargeable battery of claim 15, wherein the rechargeable battery expansion detector is configured to measure a capacitance between one of the first array of electrically conductive surfaces and one of the second array of electrically conductive surfaces.

17. The rechargeable battery of claim 13, wherein the rechargeable battery expansion detector is configured to individually measure a capacitance between each electrically conductive surface of the array of electrically conductive surfaces and a reference surface.

18. The rechargeable battery of claim 10, wherein:

the rechargeable battery expansion detector comprises a first electrically conductive plate and a second electrically conductive plate separated by an air gap;

the first electrically conductive plate is coupled to an internal surface of the housing; and

the second electrically conductive plate is coupled to an external surface of the housing.

19. The rechargeable battery of claim 18, wherein the rechargeable battery expansion detector is configured to send the expansion signal to the processing unit upon detecting an electrical connection between the first electrically conductive plate and the second electrically conductive plate.