Residual capacity correction method for battery

• US 20020105303A1
• Filed: 02/06/2002
• Published: 08/08/2002
• Est. Priority Date: 02/07/2001
• Status: Active Grant

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Kawaguchi, Kenji, Kishi, Hideki, Amazutsumi, Tooru, Tsuda, Hidenori, Nagaya, Hideyuki
• Granted Patent: US 6,930,465 B2
• Time in Patent Office: Days
• US Class Current: 320/134
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]

Abstract

In a residual capacity correction method for a battery, a count of one cycle is made each time an accumulated quantity of a charge capacity of a battery reaches a learning capacity of the battery at that time, and the learning capacity is decreased by a specified cycle degradation capacity per charge of the one cycle, alternatively a decreasing rate of the learning capacity is specified as a keeping degradation capacity while a keeping temperature and a residual capacity of the battery are used as parameters, and as a keeping time passes, the learning capacity is decreased by the keeping degradation capacity specified from the keeping temperature and the residual capacity of the battery.

Claims

1. A residual capacity correction method for a battery, comprising the steps of:

making a count of one cycle each time an accumulated quantity of a charge capacity of a battery reaches a set capacity; and

decreasing a learning capacity by a specified cycle degradation capacity per charge of the one cycle.

2. A residual capacity correction method for a battery according to claim 1, wherein the set capacity at which the count of the one cycle is made and the learning capacity is decreased, is the learning capacity of the battery.

3. A residual capacity correction method for a battery according to claim 2, wherein the cycle degradation capacity is made 0.003 to 0.15% of the learning capacity of the battery.

4. A residual capacity correction method for a battery according to claim 1, wherein the battery is a lithium ion secondary battery.

5. A residual capacity correction method for a battery according to claim 1, further comprising the steps of:

specifying a decreasing rate of the learning capacity as a keeping degradation capacity while a keeping temperature and a residual capacity of the battery are used as parameters; and

decreasing, as a keeping time passes, the learning capacity by the keeping degradation capacity specified from the keeping temperature and the residual capacity of the battery.

6. A residual capacity correction method for a battery according to claim 5, wherein the keeping degradation capacity per unit time is stored as a table while the keeping temperature and the residual capacity of the battery are made the parameters, the keeping degradation capacity per unit time is judged from the table, and the learning capacity in a keeping state is corrected.

7. A residual capacity correction method for a battery, comprising the steps of:

specifying a decreasing rate of a learning capacity as a keeping degradation capacity while a keeping temperature and a residual capacity of the battery are used as parameters; and

decreasing, as a keeping time passes, the learning capacity by the keeping degradation capacity specified from the keeping temperature and the residual capacity of the battery.

8. A residual capacity correction method for a battery according to claim 7, wherein the keeping degradation capacity per unit time is stored as a table while the keeping temperature and the residual capacity of the battery are used as the parameters, the keeping degradation capacity per unit time is judged from the table, and the learning capacity in a keeping state is corrected.

9. A residual capacity correction method for a battery according to claim 7, wherein a count of one cycle is made each time an accumulated quantity of a charge capacity of the battery reaches a set capacity, and the learning capacity is decreased by a specified cycle degradation capacity per charge of the one cycle.

10. A residual capacity correction method for a battery according to claim 9, wherein the set capacity at which the count of the one cycle is made and the learning capacity is decreased, is the learning capacity of the battery.

11. A residual capacity correction method for a battery according to claim 10, wherein the cycle degradation capacity is made 0.003 to 0.15%.

12. A residual capacity correction method for a battery according to claim 7, wherein the battery is a lithium ion secondary battery.