Protection methods, protection circuits and protection devices for secondary batteries, a power tool, charger and battery pack adapted to provide protection against fault conditions in the battery pack

• US 20080180059A1
• Filed: 03/26/2008
• Published: 07/31/2008
• Est. Priority Date: 10/14/2003
• Status: Active Grant

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Inventors: Seman, Andrew E. Jr, Francis, Jeffrey J., Trinh, Danh Thanh, Brotto, Daniele C., Yahnker, Christopher R., Phillips, Steve, Bailey, R. Roby, Carrier, Dave
• Granted Patent: US 7,602,146 B2
• Time in Patent Office: Days
• US Class Current: 320/112
• 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: B60L 53/18 Cables specially adapted for charging electric vehicles
• CPC Class Codes: H01M 10/42 Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells H01M10/60 takes precedence
• 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 10/443 in response to temperature
• 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 2200/00 Safety devices for primary or secondary batteries
• CPC Class Codes: H01M 2200/106 PTC
• 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 50/574 Devices or arrangements for the interruption of current
• CPC Class Codes: H01M 50/581 in response to temperature
• CPC Class Codes: H01M 50/583 in response to current, e.g. fuses
• CPC Class Codes: H01M 6/42 Grouping of primary cells into batteries H01M6/40 takes precedence
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/00308 : Overvoltage protection
• 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: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles

Abstract

In a cordless power tool system, protection methods, circuits and devices are provided to protect against fault conditions within a battery pack that is operatively attached to a power tool or charger, so as to prevent internal or external damage to the battery pack or attached tool or charger. The exemplary methods, circuits and devices address fault conditions such as over-charge, over-discharge, over-current, over-temperature, etc.

Claims

1-40. -40. (canceled)

41. A battery pack having over-charge protection, comprising:

a housing,

a plurality of serially-connected cells therein, and

a current interrupt mechanism to interrupt current in the cells that is triggered upon swelling of at least one cell during an over-charge event.

42. The battery pack of claim 41, wherein

the cells are serially connected between power terminals of the pack and interconnected to each other via tab connectors, the tab connectors of adjacent cells connected to each other.

43. The battery pack of claim 42, wherein the current interrupt mechanism is embodied as at least one tab connector of a swelling cell being pull apart from at least one tab connector of an adjacent cell to interrupt current.

44. The battery pack of claim 41, wherein the current interrupt mechanism comprises:

a plunger, and

a spring, the plunger restrained between the serially-connected cells and a sidewall of the battery housing under a counterforce provided by the spring, the plunger including a portion that extends partially into a recess between formed an intermediate wall and an outer sidewall of the battery pack housing, the recess including a lead wire from the pack electrically connecting the cells of the pack to a charger,

wherein swelling of the at least one cell assists the plunger to overcome spring pressure to sever the lead wire in the recess to interrupt current.

45. The battery pack of claim 44, wherein the cells are serially connected between power terminals of the pack and interconnected to each other via tab connectors, the tab connectors of adjacent cells connected to each other, and the current interrupt mechanism further includes at least one tab connector of the at least one swelling cell pulling apart from at least one tab connector of an adjacent cell to interrupt current.

46. The battery pack of claim 41, wherein the current interrupt mechanism comprises:

a plunger, and

a spring, the plunger restrained between the serially-connected cells and a sidewall of the battery housing under a counterforce provided by the spring, the plunger including a portion that extends partially into a recess, the recess extending through a sidewall of the battery pack housing and a sidewall of a charger housing,

wherein a charger lead wire electrically connecting the charger to a corresponding lead wire of the battery pack extends longitudinally along a face of the charger housing sidewall and over the recess, and

wherein swelling of the at least one cell assists the plunger to overcome spring pressure to sever the charger lead wire extending over the recess to interrupt current.

47. The battery pack of claim 46, wherein the cells are serially connected between power terminals of the pack and interconnected to each other via tab connectors, the tab connectors of adjacent cells connected to each other, and the current interrupt mechanism further includes at least one tab connector of the at least one swelling cell pulling apart from at least one tab connector of an adjacent cell to interrupt current.

48. The battery pack of claim 41, wherein the current interrupt mechanism comprises:

a plunger, and

a spring, the plunger restrained between the serially-connected cells and a sidewall of the battery housing under a counterforce provided by the spring, the plunger including a portion that extends partially into a recess between formed a sidewall of the battery pack housing and a housing of the charger,

wherein a lead wire from the cells is electrically connected to a corresponding lead wire of the charger at a contact interface, and

wherein swelling of the at least one cell assists the plunger to overcome spring pressure to eject the pack housing from the charger housing, causing a break in the contact interface to interrupt current.

49. The battery pack of claim 48, wherein the cells are serially connected between power terminals of the pack and interconnected to each other via tab connectors, the tab connectors of adjacent cells connected to each other, and the current interrupt mechanism further includes at least one tab connector of the at least one swelling cell pulling apart from at least one tab connector of an adjacent cell to interrupt current.