Method and system for battery protection employing a selectively-actuated switch

• US 7,157,882 B2
• Filed: 11/20/2003
• Issued: 01/02/2007
• Est. Priority Date: 11/22/2002
• Status: Active Grant

• Current Assignee: Milwaukee Electric Tool Corporation (Techtronic Industries Company Limited)
• Original Assignee: Milwaukee Electric Tool Corporation (Techtronic Industries Company Limited)
• Inventors: Scheucher, Karl F., Kubale, Mark A., Johnson, Todd W., Glasgow, Kevin L., Rosenbecker, Jay J., Zeiler, Jeffrey M., Grzybowski, Dennis J., Meyer, Gary D.
• Primary Examiner(s): Tso; Edward H.
• Application Number:
  US10/720,027
• Publication Number:
  US 20050007068A1
• Time in Patent Office: 1,139 Days
• Field of Search: 320/112, 320/134, 320/136
• US Class Current: 320/134
• CPC Class Codes: B25F 5/02 Construction of casings, bodies or handles B25F5/006, B25F5/008 take precedence
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/4207 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• 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 10/441 for several batteries or cells simultaneously or sequentially
• 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 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H01M 10/488 Cells or batteries combined with indicating means for external visualization of the condition, e.g. by change of colour or of light density
• CPC Class Codes: H01M 10/613 Cooling or keeping cold
• CPC Class Codes: H01M 10/623 Portable devices, e.g. mobile telephones, cameras or pacemakers
• CPC Class Codes: H01M 10/6235 Power tools
• CPC Class Codes: H01M 10/6551 Surfaces specially adapted for heat dissipation or radiation, e.g. fins or coatings
• 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: H01M 50/202 : Casings or frames around the primary casing of a single cell or a single battery
• CPC Class Codes: H01M 50/211 : adapted for pouch cells
• CPC Class Codes: H01M 50/213 : adapted for cells having curved cross-section, e.g. round or elliptic H01M50/209, H01M50/216 take precedence
• CPC Class Codes: H01M 50/247 : specially adapted for portable devices, e.g. mobile phones, computers, hand tools or pacemakers
• CPC Class Codes: H01M 50/284 : with incorporated circuit boards, e.g. printed circuit boards [PCB]
• CPC Class Codes: H01M 50/296 : characterised by terminals of battery packs terminals of batteries H01M50/543
• CPC Class Codes: H01M 50/569 : Constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals battery terminal connectors with integrated measuring arrangements G01R31/364
• CPC Class Codes: H02H 7/18 : for batteries; for accumulators
• CPC Class Codes: H02J 7/00 : Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/00038 : using passive battery identification means, e.g. resistors or capacitors identification by mechanical connections H02J7/0045
• CPC Class Codes: H02J 7/00047 : with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/0014 : Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0029 : with safety or protection devices or circuits
• CPC Class Codes: H02J 7/00309 : Overheat or overtemperature protection
• CPC Class Codes: H02J 7/0031 : using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/0042 : characterised by the mechanical construction
• CPC Class Codes: H02J 7/0045 : concerning the insertion or the connection of the batteries
• CPC Class Codes: H02J 7/0063 : with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/007 : Regulation of charging or discharging current or voltage
• CPC Class Codes: H02J 7/007182 : in response to battery voltage
• CPC Class Codes: H02J 7/007184 : in response to battery voltage gradient
• CPC Class Codes: H02J 7/007194 : of the battery
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries

Abstract

A system and method for battery protection. In some aspects, a method of conducting an operation including a battery pack, includes the acts of monitoring a first battery pack condition at a first monitoring rate, determining when a second battery pack condition reaches a threshold, after the second battery pack condition reaches the threshold, monitoring the first battery pack condition at a second monitoring rate, the second monitoring rate being different than the first monitoring rate. In some aspects, a method of conducting an operation including a battery, the battery including a cell having a voltage, power being transferable between the cell and the electrical device, a controller operable to control a function of the battery pack, the controller being operable with a voltage at least one of equal to and greater than an operating voltage threshold, the cell being operable to selectively supply voltage to the controller, includes the act of enabling the controller to operate when the voltage supplied by the cell is below the operating voltage threshold.

Claims

1. A battery pack configured to be interfaced with a power tool, the battery pack comprising:

a housing;

a cell having a voltage, power being transferable between the cell and the power tool;

a controller operable to control a function of the battery pack, the controller being operable with a voltage at least one of equal to and greater than an operating voltage threshold, the cell being operable to selectively supply voltage to the controller; and

a circuit operable to enable the controller to operate when the voltage supplied by the cell to the controller is below the operating voltage threshold of the controller, the circuit including a switch operable to selectively interrupt the transfer of power between the cell and the power tool while the power tool is being operated by a user, the switch including a FET.

2. The battery pack as set forth in claim 1 wherein the circuit is operable to supply voltage to the controller such that the voltage supplied to the controller is at least one of equal to and greater than an operating voltage threshold.

3. The battery pack as set forth in claim 2 wherein the circuit includes a boost circuit operable to boost the voltage supplied by the cell to at least one of equal to and greater than an operating voltage threshold.

4. The battery pack as set forth in claim 2 wherein the circuit includes a power source operable to supply voltage to the controller such that the voltage supplied to the controller is at least one of equal to and greater than an operating voltage threshold, the power source not being operable to supply power to the power tool.

5. The battery pack as set forth in claim 4 wherein the power source includes a power component operable to supply voltage to the controller such that the voltage supplied to the controller is at least one of equal to and greater than an operating voltage threshold.

6. The battery pack as set forth in claim 5 wherein the power component includes a capacitor operable to supply voltage to the controller such that the voltage supplied to the controller is at least one of equal to and greater than an operating voltage threshold.

7. The battery pack as set forth in claim 5 wherein the power component includes a battery cell operable to supply voltage to the controller such that the voltage supplied to the controller is at least one of equal to and greater than an operating voltage threshold.

8. The battery pack as set forth in claim 1 wherein the controller is operable to control the FET such that the voltage supplied by the cell to the controller is at least one of equal to and greater than an operating voltage threshold.

9. The battery pack as set forth in claim 1 wherein the cell is operable to supply power to the power tool to operate the power tool.

10. The battery pack as set forth in claim 9 wherein, when the cell is at a low temperature, the supply of power to the power tool causes the voltage supplied by the cell to the controller to be below the operating voltage threshold.

11. The battery pack as set forth in claim 10 wherein, when the cell is at a higher temperature, the supply of power to the power tool does not cause the voltage supplied by the cell to the controller to be below the operating voltage threshold.

12. The battery pack as set forth in claim 9 wherein, when an ambient temperature is a low temperature, the supply of power to the power tool causes the voltage supplied by the cell to the controller to be below the operating voltage threshold.

13. The battery pack as set forth in claim 12 wherein, when the ambient temperature is at a higher temperature, the supply of power to the power tool does not cause the voltage supplied by the cell to the controller to be below the operating voltage threshold.

14. The battery pack as set forth in claim 9 wherein a load on the power tool causes the voltage supplied by the cell to the controller to be below the operating voltage threshold.

15. The battery pack as set forth in claim 9 wherein the operating voltage threshold is about 5 volts.

16. The battery pack as set forth in claim 9 wherein the operating voltage threshold is about 3 volts.

17. The battery pack as set forth in claim 1 wherein the function includes interrupting the transfer of power between the cell and the power tool.

18. The battery pack as set forth in claim 17 wherein the cell is operable to supply power to the power tool to operate the power tool, and wherein the function includes interrupting the supply of power from the cell to the power tool.

19. A method of conducting an operation which includes operating a battery pack, the battery pack including a cell having a voltage, power being transferable between the cell and a power tool, a controller operable to control a function of the battery pack, the controller being operable with a voltage at least one of equal to and greater than an operating voltage threshold, the cell being operable to selectively supply voltage to the controller, and a circuit including a switch, the switch including a FET, said method comprising the act of enabling the controller to operate when the voltage supplied by the cell to the controller is below the operating voltage threshold of the controller, wherein the enabling act includes the act of controlling the FET such that the transfer of power between the cell and the power tool is selectively interrupted while the power tool is being operated by a user.

20. The method as set forth in claim 19 wherein the circuit is operable to supply voltage to the controller, and wherein the enabling act includes the act of, with the circuit, supplying a voltage to the controller such that the voltage supplied to the controller is at least one of equal to and greater than an operating voltage threshold.

21. The method as set forth in claim 20 wherein the circuit includes a boost circuit operable to boost the voltage supplied by the cell, and wherein the supplying act includes boosting the voltage supplied to the controller by the cell to at least one of equal to and greater than an operating voltage threshold.

22. The method as set forth in claim 20 wherein the circuit includes a power source operable to supply voltage to the controller, the power source not being operable to supply power to the power tool, and wherein the supplying act includes the act of supplying voltage from the power source to the controller such that the voltage supplied to the controller is at least one of equal to and greater than an operating voltage threshold.

23. The method as set forth in claim 22 wherein the power source includes a power component operable to supply voltage to the controller, and wherein the supplying act includes the act of supplying voltage from the power component to the controller such that the voltage supplied to the controller is at least one of equal to and greater than an operating voltage threshold.

24. The method as set forth in claim 23 wherein the power component includes a capacitor operable to supply voltage to the controller, and wherein the supplying act includes the act of supplying voltage from the capacitor to the controller such that the voltage supplied to the controller is at least one of equal to and greater than an operating voltage threshold.

25. The method as set forth in claim 23 wherein the power component includes a battery cell operable to supply voltage to the controller, and wherein the supplying act includes the act of supplying voltage from the battery cell to the controller such that the voltage supplied to the controller is at least one of equal to and greater than an operating voltage threshold.

26. The method as set forth in claim 19 wherein the enabling act further includes the act of controlling the FET such that the voltage supplied by the cell to the controller is at least one of equal to and greater than an operating voltage threshold.

27. The method as set forth in claim 19 and further comprising the act of supplying power from the cell to the power tool to operate the power tool.

28. The method as set forth in claim 19 and further comprising the act of, with the controller, interrupting the transfer of power between the cell and the power tool.

29. The method as set forth in claim 28 wherein the cell is operable to supply power to the power tool to operate the power tool, and wherein the interrupting act includes the act of interrupting the supply of power from the cell to the power tool.