Method for counting cycle count of a smart battery and method and device for correcting full charge capacity of a smart battery using the same

• US 20050046389A1
• Filed: 11/06/2003
• Published: 03/03/2005
• Est. Priority Date: 11/08/2002
• Status: Abandoned Application

• Current Assignee: MteQ Systems, Inc.
• Original Assignee: MteQ Systems, Inc.
• Inventors: Kim, Dong Hoon
• Application Number:
  US10/702,891
• Publication Number:
  US 20050046389A1
• Time in Patent Office: Days
• US Class Current: 320/132
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm

Abstract

A method for counting cycle count of a smart battery, a method and device for correcting full charge capacity of a smart battery, which is used as reference capacity for indicating correct remaining capacity of the battery, are disclosed. The present invention increase cycle count that is a standard for updating FCC in gradual floating variables in consideration of SOC to obtain continuous cycle count. FCC information is updated when the battery has been fully charged or the integer of the cycle count increases 1 using a predetermined FCC correction table in which FCC correction values varying with the cycle count are linearized by sections. This improves reliability in actually corrected FCC information and increases accuracy in the remaining capacity indicated on the basis of the FCC information.

Claims

1. A method for counting cycle count of a smart battery, comprising:

a first step of calculating accumulated battery charge capacity using a predetermined state of charge (SOC) capacity table in which battery capacities are stored corresponding to states of charge (SOC) of the battery, divided into a plurality of sections, and cycle counts of the battery;

a second step of obtaining a difference between the accumulated battery charge capacity when battery charging is finished and remaining capacity of the battery when battery charging starts and calculating a ratio of the difference to current full charge capacity; and

a third step of increasing the cycle count in floating variables, corresponding to the radio of the difference.

2. The method for counting cycle count of a smart battery, as claimed in claim 1, wherein the first step comprises the steps of:

calculating the remaining capacity of the battery when battery charging starts at a percentage of the full charge capacity, to decide the SOC of the battery;

linearizing a predetermined SOC capacity that is battery capacity corresponding to the SOC and cycle count from the SOC capacity table; and

summing up the SOC capacity and capacity charged from the point of time when battery charging starts, to calculate the battery charge capacity.

3. A method for counting cycle count of a smart battery, comprising:

a first step of calculating accumulated battery charge capacity using a predetermined state of charge (SOC) capacity table in which battery capacities are stored corresponding to states of charge (SOC) of the battery, divided into a plurality of sections, and cycle counts of the battery;

a second step of obtaining a difference between the accumulated battery charge capacity and remaining capacity of the battery when battery charging starts at a predetermined period and calculating a ratio of the difference to current full charge capacity; and

a third step of increasing the cycle count in floating variables, corresponding to the radio of the difference, until battery charging is finished.

4. A method for correcting full charge capacity of a smart battery, comprising:

a first step of calculating accumulated first battery charge capacity using a predetermined state of charge (SOC) capacity table in which battery capacities are stored corresponding to states of charge (SOC) of the battery, divided into a plurality of sections, and cycle counts of the battery;

a second step of obtaining a difference between the first battery charge capacity when battery charging is finished and remaining capacity of the battery when battery charging starts and calculating a ratio of the difference to current full charge capacity;

a third step of increasing the cycle count in floating variables, corresponding to the radio of the difference;

a fourth step of calculating a first FCC correction value using a predetermined FCC correction table in which FCC correction values are recorded by sections according to the cycle count of the battery when the integer of the cycle count increases 1;

a fifth step of applying a predetermined correction constant to the first FCC correction value and a second battery charge capacity RM that has been accumulated until the integer of the cycle count increases 1, excepting discharged capacity, to calculate a second FCC correction value; and

a sixth step of updating full charge capacity information with the second FCC correction value.

5. The method for correcting full charge capacity a smart battery, as claimed in claim 4, wherein the steps following the fourth step are carried out when the smart battery has been fully charged.

6. The method for correcting full charge capacity a smart battery, as claimed in claim 4, wherein the second FCC correction value is calculated according to the equation, FCC₂=W×

RM+(1−

W)×

FCC₁ (0<

W<

1), when the first and second FCC correction values are FCC₁ and FCC₂, respectively, the correction constant multiplied by the second battery charge capacity RM is W, and the correction constant multiplied by the first FCC correction value is 1−

W in the fifth step.

7. The method for correcting FCC of a smart battery, as claimed in claim 4, further comprising an error processing step between the fourth and fifth steps, the error processing step obtaining a difference between the second battery charge capacity RM and current FCC, maintaining the current FCC as the FCC information when the difference exceeds a predetermined error reference value, and executing the steps following the fifth step when the difference is lower than the error reference value.

8. The method for correcting FCC of a smart battery, as claimed in claim 4, further comprising an error processing step between the fourth and fifth steps, the error processing step obtaining a difference between the second battery charge capacity RM and the first FCC correction value, maintaining the current FCC as the FCC information when the difference exceeds a predetermined error reference value, and executing the steps after the fifth step when the difference is lower than the error reference value.

9. A device for correcting remaining capacity of a smart battery, comprising:

a battery cell for charging charges supplied from an external power supply;

a sensor for sensing voltage, current and temperature of the battery cell;

a table information storage unit including a predetermined SOC capacity table in which battery charge capacity varying with state of charge (SOC) of the battery and cycle count of the battery is recorded and a predetermined FCC correction table in which FCC correction values varying with the cycle count are linearized by sections;

a data storage unit for storing parameter information used for calculating remaining capacity of the battery, such as FCC information corrected on the basis of the FCC correction table and cycle count information counted on the basis of the SOC capacity table;

a program storage unit for storing a predetermined operation program that counts the cycle count, corrects FCC information, calculates the remaining capacity of the battery and detects the operation state of the battery; and

a controller for counting the cycle count in floating variables using the SOC correction table, updating the FCC information using the FCC correction table in real time when the cycle count increases 1 or the battery has been fully charged, and calculating the remaining capacity of the battery using data detected by the sensor and the FCC information.