Method of replacing secondary battery

• US 20010035737A1
• Filed: 04/20/2001
• Published: 11/01/2001
• Est. Priority Date: 04/28/2000
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Ogino, Youzoh, Kimura, Tadao, Mizuno, Sadao, Nakanishi, Toshiaki, Kuno, Hiromichi, Tojima, Kazuo, Nakayama, Yoshiyuki, Sekimori, Toshiyuki, Iwase, Masayoshi, Otsubo, Kouji
• Granted Patent: US 6,573,685 B2
• Time in Patent Office: Days
• US Class Current: 320/122
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H01M 10/345 Gastight metal hydride accumulators
• CPC Class Codes: H01M 10/4207 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

The present invention provides a method of replacing secondary batteries. In the method, batteries can be replaced at a low cost and performance of an overall battery assembly can be maximized after the battery replacement. The battery assembly is composed by electrically connecting a plurality of secondary batteries in series or in parallel. When a portion of the secondary batteries is judged as defective, the defective batteries are replaced by replacement batteries. In an aspect of the method, voltage is detected for every predetermined voltage detection block unit concerning secondary batteries composing the battery assembly in order to judge defects of the secondary batteries in the voltage detection block unit. Batteries in a voltage detection block unit will be replaced with replacement batteries if they are judged as defective.

Claims

1. A method of replacing a portion of a plurality of secondary batteries in which a defect is detected, with one or more replacement battery with respect to a battery assembly composed of the plurality of secondary batteries electrically connected either in series or in parallel, the method comprising

detecting each voltage of a predetermined voltage detection block for the secondary batteries composing the battery assembly in order to judge a defect of the secondary batteries in the voltage detection block unit;

and

replacing a battery judged as defective with the replacement battery in the voltage detection block unit.

2. The method according to

claim 1

, wherein the replacement battery is a secondary battery of a maximum capacity ranking among a battery group composing the battery assembly.

3. The method according to

claim 1

, wherein the secondary batteries composing the battery assembly are nickel-metal hydride batteries.

4. The method according to

claim 1

, wherein secondary batteries to be replaced by replacement batteries include both a battery detected as defective and batteries positioned in the vicinity of the defective battery and composing the battery assembly.

5. The method according to

claim 4

, wherein an ambient temperature of the battery to be replaced is detected to judge whether secondary batteries positioned in the vicinity of the defective battery to be replaced are also subjected to replacement.

6. The method according to

claim 1

, wherein an activated secondary battery is used for the replacement battery.

7. The method according to

claim 6

, wherein cyclic charge-discharge is carried out to activate the replacement secondary battery.

8. The method according to

claim 7

, wherein the total charge-discharge amount in a charge-discharge cycle conducted to activate the replacement secondary battery is at least 450% of the battery capacity.

9. The method according to

claim 6

, wherein the replacement secondary battery is activated by being left for at least five days at a battery temperature of at least 50°

C.

10. The method according to

claim 1

, wherein the replacement battery is stored at low temperature before use.

11. The method according to

claim 1

, wherein after a portion of the secondary batteries are replaced, the battery assembly is charged to have at least 100% of the battery capacity for a subsequent use.

12. The method according to

claim 1

, wherein the secondary batteries are judged as defective based on a charge amount variation of the battery to be replaced and also based on a self-discharge amount variation after leaving the battery for a predetermined period.