Method for determining remaining lifetime

Patent metadata

Field	Value
Publication number	US-9523740-B2
Application number	US-201214008849-A
Country	US
Kind code	B2
Filing date	Mar 30, 2012
Priority date	Apr 1, 2011
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

A method includes discharging an assembled battery ( 10 ) formed of a plurality of batteries until a state of charge (SOC) of the assembled battery becomes smaller or equal to a lower limit of a predetermined normal use range used in charge and discharge control of the assembled battery, measuring the discharge capacity of each of a plurality of battery blocks in the discharge of the assembled battery, the plurality of batteries being divided into the plurality of battery blocks, calculating the capacity difference in the discharge capacity among the plurality of battery blocks, and determining the remaining life of the battery block or the assembled battery based on the calculated capacity difference.

First claim

The invention claimed is:

1. A remaining lifetime determination method comprising:
discharging an assembled battery formed of a plurality of batteries until a state of charge (SOC) of the assembled battery becomes smaller or equal to a lower limit of a predetermined normal use range used in charge and discharge control of the assembled battery;
measuring a discharge capacity of each of a plurality of battery blocks in the discharge of the assembled battery, the plurality of batteries being divided into the plurality of battery blocks;
calculating a capacity difference in the discharge capacity among the plurality of battery blocks; and
determining a remaining lifetime of the battery block or the assembled battery based on the calculated capacity difference.

2. The remaining lifetime determination method according to claim 1 , wherein, when a capacity difference between a maximum value and a minimum value of the discharge capacities of the plurality of battery blocks is equal to or larger than a predetermined value, it is determined that the remaining lifetime of the assembled battery or the remaining lifetime of any battery block having a smaller discharge capacity is equal to or shorter than a predetermined period.

3. The remaining lifetime determination method according to claim 1 , wherein the lower limit is the state of charge (SOC) of 40%.

4. The remaining lifetime determination method according to claim 1 , wherein the lower limit is the state of charge (SOC) of 0%.

5. The remaining lifetime determination method according to claim 1 , wherein the assembled battery is discharged until the state of charge (SOC) of the assembled battery becomes smaller or equal to the lower limit from a reference value serving as a target in the charge and discharge control.

6. The remaining lifetime determination method according to claim 5 , wherein the lower limit is the state of charge (SOC) of 40% or 0%.

7. The remaining lifetime determination method according to claim 1 , wherein the assembled battery not subjected to charge or discharge processing after removal from a vehicle is used to perform the discharge until the state of charge (SOC) becomes smaller or equal to the lower limit.

8. The remaining lifetime determination method according to claim 7 , wherein the lower limit is the state of charge (SOC) of 40% or 0%.

Assignees

• Okumura Motoyoshi
• Ichikawa Koichi
• Matsukawa Yasushi
• Maegawa Katsunori
• Yamada Toshihiro
• Toyota Motor Co Ltd
• Primearth Ev Energy Co Ltd

Inventors

• Okumura Motoyoshi
• Ichikawa Koichi
• Matsukawa Yasushi
• Maegawa Katsunori
• Yamada Toshihiro

Classifications

• G01R31/3679

  Physics · mapped topic

• G01R31/3658

  Physics · mapped topic

• G01R31/3606 Primary

  Physics · mapped topic

• G01R31/392 Primary

  Determining battery ageing or deterioration, e.g. state of health · CPC title

• G01R31/396

  Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery · CPC title