Electrical device system and battery pack

• US 9,341,681 B2
• Filed: 03/28/2014
• Issued: 05/17/2016
• Est. Priority Date: 04/05/2013
• Status: Active Grant

• Current Assignee: Makita Corporation
• Original Assignee: Makita Corporation
• Inventors: Kobayakawa, Tadahiko, Suzuki, Hitoshi, Fukumoto, Masaaki
• Primary Examiner(s): Hollington, Jermele M
• Assistant Examiner(s): RAJAPUTRA, SURESH KS
• Application Number:
  US14/228,850
• Publication Number:
  US 20140300366A1
• Time in Patent Office: 781 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G01R 19/12 Measuring rate of change
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: H01M 10/4257 Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• CPC Class Codes: H01M 10/441 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 2010/4278 Systems for data transfer from batteries, e.g. transfer of battery parameters to a controller, data transferred between battery controller and main controller
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

An electrical device system having a battery pack, an electrical device, and a charging device, includes: a current detecting unit that detects a battery current flowing through the battery during a charge to or a discharge from the battery; a battery state detecting unit that detects at least one of a battery voltage and a temperature of a heat generating unit; and a determining unit that estimates an amount of change in at least one of the battery voltage and the temperature of the heat generating unit, based on the battery current, and calculates an amount of actual change in at least one of the battery voltage and the temperature of the heat generating unit, wherein the determining unit determines that the current detecting unit is abnormal, when the difference between the calculated amount of actual change and the estimated amount of change is a default value or more.

Claims

1. An electrical device system provided with a battery pack having a rechargeable battery, an electrical device of which a power source is the battery pack, and a charging device that charges the battery pack, the system comprising:

a current detecting unit that detects a battery current flowing through the battery during a charge to or a discharge from the battery;

a battery state detecting unit that detects at least one of a battery voltage and a temperature of a heat generating unit that generates heat when the battery current flows; and

a determining unit that estimates an amount of change in at least one of the battery voltage detected by the battery state detecting unit and the temperature of the heat generating unit based on the battery current detected by the current detecting unit during a charge to or a discharge from the battery, and calculates an actual amount of change in at least one of the battery voltage detected by the battery state detecting unit and the temperature of the heat generating unit, wherein the determining unit determines that the current detecting unit is abnormal when a difference between the calculated actual amount of change and the estimated amount of change is a default value or more, wherein the determining unit includes a counting unit that counts a number of times the difference between the actual amount of change and the estimated amount of change is determined to be the default value or more, and, when a count value by the counting unit reaches a predetermined value, determines that the current detecting unit is abnormal.

2. The electrical device system according to claim 1, wherein the determining unit, when determining that the current detecting unit is abnormal, stores the information in a storage unit.

3. The electrical device system according to claim 2, wherein the storage unit is a non-volatile memory.

4. The electrical device system according to claim wherein the determining unit, when a charge to the battery is completed, sets the count value of the counting unit to an initial value.

5. A battery pack having a rechargeable battery, the battery pack comprising:

a current detecting unit that detects a battery current flowing through the battery;

a battery state detecting unit that detects at least one of a battery voltage and a temperature of the battery; and

a determining unit that estimates an amount of change in at least one of the battery voltage and the temperature detected by the battery state detecting unit, based on the battery current detected by the current detecting unit, and calculates an actual amount of change in at least one of the battery voltage and the temperature detected by the battery state detecting unit, wherein the determining unit determines that the current detecting unit is abnormal when a difference between the calculated actual amount of change and the estimated amount of change is a default value or more, wherein the determining unit includes a counting unit that counts a number of times the difference between the actual amount of change and the estimated amount of change is determined to be the default value or more, and, when a count value by the counting unit reaches a predetermined value, determines that the current detecting unit is abnormal.