Battery pack, electrical device, and control method therefor

• US 10,218,036 B2
• Filed: 02/19/2014
• Issued: 02/26/2019
• Est. Priority Date: 03/13/2013
• Status: Active Grant

• Current Assignee: Envision AESC Energy Devices Ltd.
• Original Assignee: NEC Energy Devices, Ltd. (Envision Group /TX/)
• Inventors: Yoshida, Tadahiro
• Primary Examiner(s): Chmielecki, Scott J.
• Application Number:
  US14/775,194
• Publication Number:
  US 20160036096A1
• Time in Patent Office: 1,833 Days
• Field of Search: None
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• 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 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H01M 10/63 Control systems charging or discharging in response to temperature H01M10/44 , H01M10/443; measurement of temperature H01M10/48 , H01M10/486
• CPC Class Codes: H01M 10/633 characterised by algorithms, flow charts, software details or the like
• 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 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/0049 Detection of fully charged condition
• CPC Class Codes: H02J 7/005 Detection of state of health [SOH]
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Provided is a battery pack capable of more reliably preventing adverse effects from being externally exerted. MCU (26) measures, as index values pertaining to the deterioration state of battery unit (1), at least two or more from among: a capacity reduction rate that is the reduction rate of the full-charge capacity of battery unit (1) from an initial value; a cycle count representing the number of times that a cycle, in which battery unit (1) is charged until the cumulative value of charge quantities charged to battery unit (1) reaches a prescribed charge quantity, has been performed; the number of times that battery unit (1) has been charged; time elapsed from the manufacturing of battery unit (1); cell voltages that are the voltages of secondary battery cells 11; and determines whether battery unit (1) has reached its end of life by using the measured index values. Monitoring IC 25 suspends the use of battery unit (1) when battery unit (1) has reached its end of life.

Claims

1. A battery pack comprising:

a battery unit that includes secondary battery cells;

a determination unit programed to measure, as index values pertaining to a deterioration state of the battery unit, time elapsed from when the battery unit was manufactured, and said determination unit programed to determine whether the battery unit has reached its end of life by using the measured index values;

a suspension unit programed to suspend use of the battery unit when the battery unit has been determined to have reached its end of life; and

a temperature detection unit programed to detect a temperature of the battery unit,

wherein the determination unit is programed to correct the measured elapsed time based on the temperature and is programed to determine whether the battery unit has reached its end life by using corrected that is the corrected elapsed time.

2. The battery pack according to claim 1, wherein the determination unit is programmed to measure, as a number of charging times, the number of times that charging of the battery unit has been started and continued for a prescribed period of time or longer.

3. The battery pack according to claim 1, wherein the determination unit is programmed to measure, as a number of charging times, the number of times that the battery unit has been charged to a full-charge state.

4. The battery pack according to claim 1, wherein the determination unit is programmed to determine, for the measured index values, whether the index value satisfies a battery cycle life condition corresponding to the index value, and to determine whether the battery unit has reached its end of life based on a result of the determination.

5. The battery pack according to claim 4, wherein:

the determination unit is programmed to determine that the battery unit has reached its end of life when the number of index values satisfying the life conditions is equal to or greater than a prescribed number; and

the prescribed number is 1.

6. The battery pack according to claim 4, wherein:

the battery cycle life condition corresponding to a reduced capacity value, that is a value reduced from an initial value of a full-charge capacity of the battery unit, is a condition in which the reduced capacity value is smaller than a preset threshold value; and

the threshold value is within a range of 40% to 60%.

7. An electrical device comprising the battery pack according to claim 1.

9. The battery pack according to claim 1, wherein the determination unit comprises a micro controller.

8. A method for controlling a battery pack including a battery unit that includes secondary battery cells,

the method comprising the steps of:

measuring, as index values pertaining to a deterioration state of the battery unit, time elapsed from when the battery unit was manufactured;

detecting a tem erasure of the battery unit;

correcting the measured elapsed time based on the temperature;

determining whether the battery unit has reached its end of life by using corrected time that is corrected elapsed time; and

suspending use of the battery unit when the battery unit has been determined to have reached its end of life.