Battery pack

• US 8,471,532 B2
• Filed: 05/17/2011
• Issued: 06/25/2013
• 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: Johnson, Todd W., Grzybowski, Dennis J., Kubale, Mark A., Rosenbecker, Jay J., Scheucher, Karl F., Meyer, Gary D., Zeiler, Jeffrey M., Glasgow, Kevin L.
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): BOATENG, ALEXIS ASIEDUA
• Application Number:
  US13/109,150
• Publication Number:
  US 20110215767A1
• Time in Patent Office: 770 Days
• Field of Search: 320/120, 320/132, 320/134, 320/150, 320/112, 320/113, 320/114, 320/115, 320/116, 320/119, 320/118, 320/135, 320/136
• US Class Current: 320/150
• CPC Class Codes: B25F 5/00 Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
• 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 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• 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 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 50/20 Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders structural combination of accumulators with charging apparatus H01M10/46
• 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: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from 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 7/0045 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 7/007184 in response to battery voltage gradient

Abstract

A system and method for battery protection. In some aspects, a battery pack includes a housing, a cell supported by the housing, a circuit supported by a flexible circuit board. The circuit is operable to control a function of the battery pack.

Claims

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

a battery pack housing;

a plurality of terminals configured to be interfaced with corresponding terminals of the handheld power tool; and

a plurality of rechargeable lithium-ion battery cells arranged within and supported by the housing, each of the plurality of battery cells having a respective state of charge, the battery pack having a battery pack state of charge, power being transferable from the plurality of battery cells to the handheld power tool;

wherein the transfer of power from the battery pack is controlled by a control component and a semiconducting switch based on a state of charge of the battery pack, the semiconducting switch electrically connected to at least one of the plurality of terminals, and

wherein a discharge current from the battery pack is regulated based on the semiconducting switch being controlled into one of a first state and a second state by the control component to selectively enable the transfer of power from the plurality of battery cells to the handheld power tool.

2. The battery pack of claim 1, wherein the battery pack housing includes at least one rail and at least one groove for interfacing the battery pack with the handheld power tool.

3. The battery pack of claim 2, wherein the at least one rail and the at least one groove extend along a first axis.

4. The battery pack of claim 3, wherein the first axis is parallel to the plurality of terminals configured to be interfaced with corresponding terminals of the handheld power tool.

5. The battery pack of claim 1, further comprising a heat sink in heat transfer relationship with the control component.

6. The battery pack of claim 1, wherein the switch is in a heat transfer relationship with a heat sink.

7. The battery pack of claim 6, wherein the switch is a field-effect transistor (“

FET”

).

8. The battery pack of claim 1, wherein the first state of the semiconducting switch interrupts the discharge current from the plurality of battery cells to the handheld power tool.

9. The battery pack of claim 1, wherein the handheld power tool is one of a circular saw and a driver drill.

10. The battery pack of claim 1, wherein the plurality of battery cells have a lithium manganese chemistry.

11. The battery pack of claim 1, further comprising a locking assembly operable to lock the battery pack to the handheld power tool, the locking assembly including an actuator.

12. The battery pack of claim 1, wherein the plurality of battery cells are electrically connected in a partial parallel and partial series arrangement.

13. The battery pack of claim 1, wherein the control component is operable to prevent the battery pack from entering an over-discharged state based on predetermined battery voltage threshold.

14. The battery pack of claim 13, wherein the control component is a microprocessor.

15. The battery pack of claim 1, further comprising a fuel gauge including a plurality of light-emitting diodes.