METHOD AND SYSTEM FOR BATTERY PROTECTION EMPLOYING SAMPLING OF MEASUREMENTS

• US 20070103116A1
• Filed: 12/28/2006
• Published: 05/10/2007
• 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: Johnson, Todd, Meyer, Gary, Rosenbecker, Jay, Zeiler, Jeffrey, Kubale, Mark, Scheucher, Karl, Glasgow, Kevin, Grzybowski, Dennis
• Granted Patent: US 7,342,381 B2
• Time in Patent Office: Days
• US Class Current: 320/114
• 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 power tool battery pack operable to supply power to a power tool includes a controller. The controller is operable to sample a battery pack condition in at least a first sampling mode and a second sampling mode to produce a plurality of measurements. The controller is further operable to average the plurality of measurements to produce an averaged measurement, and operable to modify operation of the battery pack when the averaged measurement is outside a specified range.

Claims

1. A power tool battery pack operable to supply power to a power tool, the battery pack comprising:

a battery cell operable to supply a discharge current to power the power tool; and

a controller operable to control an operation of the battery pack when a battery pack condition is within a specified range,

the controller being operable to sample the battery pack condition in at least a first sampling mode and a second sampling mode to produce a plurality of measurements, the first sampling mode having a first sampling rate and the second sampling mode having a second sampling rate, the first sampling rate being less than the second sampling rate, and

the controller being operable to average the plurality of measurements to produce an averaged measurement, the controller being operable to modify the operation of the battery pack when the averaged measurement is outside the specified range.

2. The power tool battery pack of claim 1, further comprising a switch coupled to the controller and operable to interrupt the supply of discharge current in response to the controller.

3. The power tool battery pack of claim 2, wherein the controller is operable to control the switch to interrupt the supply of discharge current when the averaged measurement is outside the specified range.

4. The power tool battery pack of claim 1, wherein the battery cell has a state of charge, and wherein the battery pack condition is a state of charge of the battery cell.

5. The power tool battery pack of claim 1, wherein the battery cell has a lithium-based chemistry.

6. The power tool battery pack of claim 5, wherein the chemistry is lithium manganese.

7. The power tool battery pack of claim 1, wherein the battery pack condition is a temperature of the battery pack.

8. The power tool battery pack of claim 1, wherein the battery pack condition is a state of charge of the battery pack.

9. The power tool battery pack of claim 1, wherein the controller is operable to average the plurality of measurements in a first averaging mode and a second averaging mode to produce an averaged measurement, the first averaging mode utilizing a first number of samples and the second averaging mode utilizing a second number of samples, the first number of samples being greater than the second number of samples.

10. A power tool battery pack operable to supply power to a power tool, the battery pack comprising:

a housing;

a plurality of battery cells positioned in the housing and operable to supply a discharge current to power the power tool, the battery cells having a lithium-based chemistry; and

a controller operable to control an operation of the battery pack,

the controller being operable to sample a battery pack condition in at least a first sampling mode and a second sampling mode to produce a plurality of measurements, the first sampling mode having a first sampling rate and the second sampling mode having a second sampling rate, the first sampling rate being less than the second sampling rate, and

the controller being operable to average the plurality of measurements to produce an averaged measurement, the controller being operable to modify the operation of the battery pack when the averaged measurement is outside a specified range.