Battery pack, electrical device, and control method therefor

Patent metadata

Field	Value
Publication number	US-10218036-B2
Application number	US-201414775194-A
Country	US
Kind code	B2
Filing date	Feb 19, 2014
Priority date	Mar 13, 2013
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

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.

First claim

The invention claimed is:

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 .

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.

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

Assignees

• Nec Energy Devices Ltd

Inventors

• Yoshida Tadahiro

Classifications

• H02J7/82

  Control of state of charge [SOC] · CPC title

• H02J7/977

  of the battery · CPC title

• H02J7/855

  with circuits adapted for supplying loads from the battery · CPC title

• H02J7/825

  Detection of fully charged condition · CPC title

• H02J7/84

  Control of state of health [SOH] · CPC title