Battery pack producing method and battery pack

• US 20080315835A1
• Filed: 06/12/2008
• Published: 12/25/2008
• Est. Priority Date: 06/20/2007
• Status: Active Grant

• Current Assignee: Panasonic EV Energy Company, Limited (Toyota Motor Corporation)
• Original Assignee: Panasonic EV Energy Company, Limited (Toyota Motor Corporation)
• Inventors: Okumura, Motoyoshi, Maegawa, Katsunori
• Granted Patent: US 8,742,723 B2
• Time in Patent Office: Days
• US Class Current: 320/116
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: H01M 10/4207 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02W 30/84 Recycling of batteries or fuel cells

Abstract

Provided is a battery pack producing method and a battery pack capable of suppressing defects such as overcharging or overdischarging in one or more of the used secondary batteries constituting a battery pack, and sufficiently exhibiting the performance of the used secondary batteries of the battery pack. This method includes an obtaining process for obtaining each full charge capacity of the used secondary batteries, a selecting process for selecting one or more used secondary batteries having similar full charge capacities from the used secondary batteries whose full charge capacities have been obtained, and an assembling process for assembling the selected secondary batteries.

Claims

1. A method of producing a battery pack composed by combining a plurality of secondary batteries, the method comprising:

an obtaining process for obtaining a full charge capacity of each of the secondary batteries that have already been used;

a selecting process for selecting more than one used secondary batteries having similar full charge capacities from the used secondary batteries whose full charge capacities have been obtained; and

an assembling process for assembling the selected used secondary batteries to constitute the battery pack.

2. The method of producing a battery pack according to claim 1, wherein the selecting process includes selecting the used second batteries so that a difference in full charge capacity between the used secondary battery of the largest full charge capacity and the used secondary battery of the smallest full charge capacity among the plurality of selected used secondary batteries constituting the battery pack is within 10% of the full charge capacity of the used secondary battery of the smallest full charge capacity.

3. The method of producing a battery pack according to claim 1, wherein the assembling process includes arranging the selected used secondary batteries so that the used secondary battery having a relatively large full charge capacity is placed in a position of the battery pack where battery temperature will become relatively higher than others during use and the used secondary battery having a relatively small full charge capacity is placed in another position of the battery pack where the battery temperature will become relatively lower during use.

4. The method of producing a battery pack according to claim 3, wherein the assembling process includes a process of arranging the selected used secondary batteries in a row to constitute the battery pack so that the used secondary battery having a smallest full charge capacity is placed at one end of the row and the used secondary battery having a second smallest full charge capacity is placed at the other end of the row.

5. A battery pack comprising:

a plurality of used secondary batteries combined for reuse,

wherein a difference in full charge capacity between the used secondary battery of the largest full charge capacity and the used secondary battery of the smallest full charge capacity among the plurality of used secondary batteries constituting the battery pack is within 10% of the full charge capacity of the used secondary battery of the smallest full charge capacity.

6. The battery pack according to claim 5, wherein

the used secondary batteries are arranged so that the used secondary battery having a relatively large full charge capacity is placed in a position of the battery pack where battery temperature will become relatively higher (than others) during use and the used secondary battery having a relatively small full charge capacity is placed in another position of the battery pack where the battery temperature will become relatively lower during use.

7. The battery pack according to claim 6, wherein

the used secondary batteries are arranged in a row so that the used secondary battery having a smallest full charge capacity is placed at one end of the row and the used secondary battery having a second smallest full charge capacity is placed at the other end of the row.