Battery pack having a film thermistor and a dip thermistor

Patent metadata

Field	Value
Publication number	US-12237481-B2
Application number	US-201917297279-A
Country	US
Kind code	B2
Filing date	Nov 7, 2019
Priority date	Nov 30, 2018
Publication date	Feb 25, 2025
Grant date	Feb 25, 2025

Abstract

A battery pack contains a plurality of battery cells that includes a first battery cell and a second battery cell; a first thermistor disposed closest to the first battery cell among the battery cells; a second thermistor disposed closest to the second battery cell among the battery cells. A case of the battery pack holds the battery cells, the first thermistor, and the second thermistor. The first battery cell is disposed such that at least one of the other battery cells is interposed between the first battery cell and a wall surface of the case in a direction orthogonal to a longitudinal direction of the first battery cell. The second battery cell is disposed such that none of the other battery cells is interposed between the second battery cell and the wall surface of the case in a direction orthogonal to a longitudinal direction of the second battery cell.

First claim

The invention claimed is:

1. A battery pack comprising:
a plurality of battery cells that includes a first battery cell and a second battery cell;
a circuit board;
a first thermistor comprising a film thermistor connected to the circuit board and disposed closest to the first battery cell among the plurality of battery cells;
a second thermistor comprising a dip thermistor connected to the circuit board and disposed closest to the second battery cell among the plurality of battery cells; and
a case accommodating the plurality of battery cells, the circuit board, the first thermistor, and the second thermistor,
wherein:
the first battery cell is disposed at a position where at least one of the battery cells is interposed between the first battery cell and a wall surface of the case in a direction orthogonal to a longitudinal direction of the first battery cell,
the second battery cell is disposed at a position where no other battery cell is interposed between the second battery cell and the wall surface of the case in a direction orthogonal to a longitudinal direction of the second battery cell,
the film thermistor extends from the circuit board toward the first battery cell, and passes through spaces between two adjacent battery cells of the plurality of battery cells, the two adjacent battery cells being different from the first battery cell and the second battery cell, and
the dip thermistor extends from the circuit board toward the second battery cell, and passes through spaces between the plurality of battery cells and a wall surface of the case.

2. The battery pack according to claim 1 , wherein the case has an air supply hole through which cooler air is introduced and an air discharge hole through which warmer air is discharged.

3. The battery pack according to claim 2 , wherein:
the second thermistor is spaced apart from the air supply hole by a first distance,
the second thermistor is spaced apart from the air discharge hole by a second distance, and
the first distance is shorter than the second distance.

4. The battery pack according to claim 2 , wherein:
the first thermistor is spaced apart from the air discharge hole by a third distance,
the first thermistor is spaced apart from the air supply hole by a fourth distance, and
the third distance is shorter than the fourth distance.

5. The battery pack according to claim 2 , wherein the circuit board is disposed between the air discharge hole and the plurality of battery cells.

6. A battery pack, comprising:
a plurality of battery cells that includes a first battery cell and a second battery cell;
a circuit board;
a first thermistor comprising a film thermistor connected to the circuit board and disposed closest to the first battery cell among the plurality of battery cells;
a second thermistor comprising a dip thermistor connected to the circuit board and disposed closest to the second battery cell among the plurality of battery cells; and
a case accommodating the plurality of battery cells, the first thermistor and the second thermistor,
wherein
the plurality of battery cells includes:
an upper battery cell group disposed at a position facing an upper surface of the case;
a lower battery cell group disposed at a position facing a lower surface of the case; and
a middle battery cell group disposed between the upper battery cell group and the lower battery cell group,

the first battery cell is included in the middle battery cell group,
the second battery cell is included in either the upper battery cell group or the lower battery cell group,
the film thermistor extends from the circuit board toward the first battery cell, and passes through spaces between two adjacent battery cells of the plurality of battery cells, the two adjacent battery cells being different from the first battery cell and the second battery cell, and
the dip thermistor extends from the circuit board toward the second battery cell, and passes through spaces between the plurality of battery cells and a wall surface of the case.

7. The battery pack according to claim 5 , wherein:
the second thermistor is spaced apart from the air supply hole by a first distance,
the second thermistor is spaced apart from the air discharge hole by a second distance,
the first thermistor is spaced apart from the air discharge hole by a third distance,
the first thermistor is spaced apart from the air supply hole by a fourth distance,
the first distance is shorter than the second distance, and
the third distance is shorter than the fourth distance.

8. The battery pack according to claim 7 , wherein:
the plurality of battery cells includes:
an upper battery cell group disposed in an upper row;
a lower battery cell group disposed in a lower row; and
a middle battery cell group disposed between the upper battery cell group and the lower battery cell group,

the middle battery cell group includes the first battery cell, and
either the upper battery cell group or the lower battery cell group includes the second battery cell.

9. The battery pack according to claim 8 , wherein:
the upper battery cell group is disposed closest to an upper surface of the case, and
the lower battery cell group is disposed closest to a lower surface of the case.

10. A battery pack comprising:
a plurality of battery cells that includes a first battery cell and a second battery cell;
a circuit board;
a first thermistor connected to the circuit board and disposed closest to the first battery cell among the plurality of battery cells;
a second thermistor connected to the circuit board and disposed closest to the second battery cell among the plurality of battery cells; and
a case accommodating the plurality of battery cells, the circuit board, the first thermistor, and the second thermistor,
wherein:
the first battery cell is disposed at a position where at least one of the battery cells is interposed between the first battery cell and a wall surface of the case in a direction orthogonal to a longitudinal direction of the first battery cell,
the second battery cell is disposed at a position where no other battery cell is interposed between the second battery cell and the wall surface of the case in a direction orthogonal to a longitudinal direction of the second battery cell,
the first thermistor extends from the circuit board toward the first battery cell, and passes through spaces between two adjacent battery cells of the plurality of battery cells, the two adjacent battery cells being different from the first battery cell and the second battery cell, and
the second thermistor extends from the circuit board toward the second battery cell, and passes through spaces between the plurality of battery cells and the wall surface of the case.

11. The battery pack according to claim 10 , wherein the case has an air supply hole through which cooler air is introduced and an air discharge hole through which warmer air is discharged.

12. The battery pack according to claim 11 , wherein:
the second thermistor is spaced apart from the air supply hole by a first distance,
the second thermistor is spaced apart from the air discharge hole by a second distance, and
the first distance is shorter than the second distance.

13. The battery pack according to claim 11 , wherein:
the first thermistor is spaced apart from the air discharge hole by a third distance,
the first thermistor is spaced apart from the air supply hole by a fourth distance, and
the third distance is shorter than the fourth distance.

14. The battery pack according to claim 11 , wherein the circuit board is disposed b

Assignees

• Makita Corp

Inventors

• Nakatani Kohei
• Tanaka Kazuya
• Uesugi Hiroki

Classifications

• H01M50/262

  with fastening means, e.g. locks · CPC title

• H01M50/227

  Organic material · CPC title

• H01M10/48

  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 title

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title

• H01M10/482

  for several batteries or cells simultaneously or sequentially · CPC title