Battery having a built-in controller to extend battery service run time

• US 6,118,248 A
• Filed: 04/02/1998
• Issued: 09/12/2000
• Est. Priority Date: 04/02/1998
• Status: Expired due to Term

• Current Assignee: Board of Trustees of The University of Illinois
• Original Assignee: The Procter & Gamble Company
• Inventors: Gartstein, Vladimir, Nebrigic, Dragan Danilo
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US09/054,191
• Time in Patent Office: 894 Days
• Field of Search: 320/106, 320/107, 320/108, 320/112, 320/113, 320/128, 320/135, 320/136
• US Class Current: 320/107
• CPC Class Codes: H01M 10/4257 Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• CPC Class Codes: H01M 10/448 End of discharge regulating measures
• 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: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A rechargeable battery having a built-in controller is disclosed that extends the service run time of the battery. The controller may extend the service run time of a rechargeable battery, for example, by ending the discharge cycle at the optimal discharge depth in order to maximize the number and efficiency of charge cycles. The controller may also control the charge cycle of each electrochemical cell of a rechargeable battery. The rechargeable battery may be a single-cell battery, a universal single-cell battery, a multiple-cell battery or a multiple-cell hybrid battery. Each individual cell preferably has a built-in controller that controls the discharge and charge cycles of that cell. In addition, the rechargeable battery may also include a remote charging system.

Claims

1. A rechargeable battery useful with a device having a cut-off voltage and an external charger that supplies a charging current, the rechargeable battery comprising:

(a) a container having a positive terminal and a negative terminal;

(b) a rechargeable electrochemical cell disposed within said container, said cell having a positive electrode, a negative electrode, a cell voltage measured across said positive electrode and said negative electrode of said cell, and a nominal voltage; and

(c) a controller electrically connected between said electrodes of said cell and said terminals of said container to create an output voltage measured across said positive terminal and said negative terminal of said container, said controller is adapted to end a discharge cycle of said cell by electronically disconnecting said electrodes of said cell from said terminals of said container and to control the charging current of the external charging circuit to charge said cell during a charge cycle.

2. The rechargeable battery of claim 1, wherein the rechargeable battery is selected from the group of a single-cell battery, a universal single-cell battery, a multiple-cell battery and a multiple-cell hybrid battery.

3. The rechargeable battery of claim 1, wherein said rechargeable battery is adapted to be electrically connected as one of an integer number of batteries in series with the device, said output voltage being greater than or equal to the cut-off voltage of the device divided by said integer number of batteries.

4. The rechargeable battery of claim 1, wherein said rechargeable battery is a multiple-cell battery, said battery further comprising a positive output terminal and a negative output terminal;

said container, said cell and said controller forming a first cell unit;

said first cell unit being one of an integer number of cell units electrically connected in series between said positive output terminal and said negative output terminal, said output voltage being greater than or equal to the cut-off voltage of the device divided by said integer number of cell units.

5. The rechargeable battery of claim 1, wherein said controller is adapted to electronically disconnect said electrodes of said cell from said terminals of said container when said cell voltage falls to a predetermined voltage level during said discharge cycle.

6. The rechargeable battery of claim 1, wherein said cell further comprises an internal impedance, said controller being adapted to electronically disconnect said electrodes of said cell from said terminals of said container when said cell is discharged to a predetermined discharge depth as indicated by said internal impedance during said discharge cycle.

7. The rechargeable battery of claim 1, wherein said controller is adapted to receive the charging current of the external charger from said terminals of said container.

8. The rechargeable battery of claim 1, wherein said controller includes a coil element that is adapted to be electromagnetically coupled to the external charger during said charge cycle, said controller being adapted to receive the charging current of the external charger from said coil element.

9. A rechargeable battery useful with a device having a cut-off voltage, and an external charger that supplies a charging current, the rechargeable battery comprising:

(a) a container having a positive terminal and a negative terminal;

(b) a rechargeable electrochemical cell disposed within said container, said cell having a positive electrode, a negative electrode, a cell voltage measured across said positive electrode and said negative electrode of said cell, and a nominal voltage; and

(c) a controller electrically connected between said electrodes of said cell and said terminals of said container to create an output voltage measured across said positive terminal and said negative terminal of said container, said controller including a converter that converts said cell voltage to said output voltage during a discharge cycle of the battery, said controller being adapted to extend the service run time of the battery by ending said discharge cycle by electronically disconnecting said electrodes of said cell from said terminals of said container, and to control the charging current of the external charger to charge said rechargeable cell, said controller also adapted to convert the charging current of the external charger to a cell charging current during a charge cycle.

10. The rechargeable battery of claim 9, wherein said controller includes a bi-directional converter, said bidirectional converter adapted to be controlled by said controller to convert said cell voltage to said output voltage during said discharge cycle and to convert the charging current of the external charger to said cell charging current during said charge cycle.

11. The rechargeable battery of claim 9, wherein said controller electronically disconnects said electrodes of said cell from the charging current of the external charger when said controller determines that said cell is charged to about 100% of a capacity of said cell.

12. The rechargeable battery of claim 9, wherein said controller determines a cell charge level using one or more conditions of the group selected from said cell voltage, an internal impedance of said cell, a hydrogen gas concentration in said cell, a temperature of said cell, and a gas pressure in said cell.

13. A remote battery charging system comprising:

(a) an external charger that supplies a charging current, said external charger comprising a primary coil; and

(b) a rechargeable battery comprising;

(i) a container having a positive terminal and a negative terminal;

(ii) a rechargeable electrochemical cell disposed within said container, said cell having a positive electrode electrically connected to said positive terminal of said container, a negative electrode electrically connected to said negative terminal of said container, a cell voltage measured across said positive and said negative electrodes of said cell, and a nominal voltage; and

(iii) a controller electrically connected to said positive and said negative electrodes of said cell, said controller including a secondary coil that is adapted to be electromagnetically coupled with said primary coil of said external charger during a charge cycle, said secondary coil receiving said charging current of said external charger, and said controller controlling said charging current of said external charger to a cell charging current during said charge cycle, wherein said controller is adapted to be electrically connected between said electrodes of said cell and said terminals of said container to create an output voltage measured across said positive terminal and said negative terminal of said container and wherein said controller is adapted to extend the service run time of said battery by electronically disconnecting said electrodes of said cell from said terminals of said container during a discharge cycle.

14. The remote battery charging system of claim 13, wherein said controller further comprises a bi-directional converter that converts said charging current of said external charger to a cell charging current during said charge cycle, and converts said cell voltage to said output voltage during said discharge cycle.

15. A method of extending a service run time of a rechargeable battery, the method comprising the steps of:

(a) providing a rechargeable battery including;

(i) a container having a positive terminal and a negative terminal;

(ii) a rechargeable electrochemical cell disposed within said container, said cell having a positive electrode, a negative electrode, a cell voltage measured across said positive electrode and said negative electrode of said cell, and a nominal voltage; and

(iii) a controller electrically connected between said electrodes of said cell and said terminals of said container to create an output voltage measured across said positive terminal and said negative terminal of said container;

(b) electrically connecting said battery to a device having a cut-off voltage; and

(c) ending a discharge cycle of said battery by electrically disconnecting said electrodes of said cell from said terminals of said container when a discharge depth of said battery reaches a predetermined discharge level.

16. The method of claim 15, further comprising the steps of:

(d) receiving a charging current;

(e) controlling said charging current to charge said cell.

17. The method of claim 15, wherein said predetermined discharge level is an optimal discharge depth.

18. The method of claim 17, wherein said optimal discharge depth is less than said cut-off voltage of said device.