EP-4741850-A1 - APPARATUS AND METHOD FOR ESTIMATING CAPACITY OF BATTERY

EP4741850A1EP 4741850 A1EP4741850 A1EP 4741850A1EP-4741850-A1

Abstract

A battery capacity estimating apparatus according to an embodiment of the present disclosure includes: a measurement unit that measures the pack capacity of a battery pack and the voltage of each of a plurality of batteries included in the battery pack during a charging-discharging process; and a control unit. The control unit is configured to calculate the relative capacity ratio among the plurality of batteries based on the voltage range of each of the plurality of batteries, and estimate the capacity of each of the plurality of batteries based on the pack capacity and the relative capacity ratio.

Inventors

KIM, JI-YEON
KIM, YOUNG-DEOK
PARK, JUN-CHEOL
CHOI, SOON-JU
KIM, DAE-SOO

Assignees

LG Energy Solution, Ltd.

Dates

Publication Date: 20260513
Application Date: 20250219

Claims (13)

A battery capacity estimating apparatus comprising: a measurement unit configured to measure a pack capacity of a battery pack and a voltage of each of a plurality of batteries included in the battery pack during a charging-discharging process; and a control unit configured to calculate a relative capacity ratio among the plurality of batteries based on a voltage range of each of the plurality of batteries, and estimate a capacity of each of the plurality of batteries based on the pack capacity and the relative capacity ratio.
The battery capacity estimating apparatus according to claim 1, wherein the control unit is configured to: determine the voltage range of each of the plurality of batteries; adjust the determined plurality of voltage ranges to correspond to each other to calculate a change ratio of each of the plurality of batteries; and calculate the relative capacity ratio of each of the plurality of batteries based on the calculated plurality of change ratios.
The battery capacity estimating apparatus according to claim 2, wherein the control unit is configured to set one of the plurality of voltage ranges as a reference voltage range, and adjust the plurality of voltage ranges to correspond to the reference voltage range to calculate the plurality of change ratios.
The battery capacity estimating apparatus according to claim 3, wherein the control unit is configured to calculate a range value representing a size of each of the plurality of voltage ranges, and calculate a ratio of a range value of the reference voltage range to the range value of each of the plurality of voltage ranges to calculate the plurality of change ratios.
The battery capacity estimating apparatus according to claim 2, wherein the control unit is configured to set one of the plurality of change ratios as a reference change ratio, and calculate the relative capacity ratio of each of the plurality of batteries based on the plurality of change ratios and the reference change ratio.
The battery capacity estimating apparatus according to claim 5, wherein the control unit is configured to calculate a ratio of the reference change ratio to each of the plurality of change ratios to calculate the relative capacity ratio of each of the plurality of batteries.
The battery capacity estimating apparatus according to claim 5, wherein the control unit is configured to set a largest value among the plurality of change ratios as the reference change ratio.
The battery capacity estimating apparatus according to claim 1, wherein the control unit is configured to estimate the capacity of each of the plurality of batteries by multiplying the pack capacity by the relative capacity ratio.
The battery capacity estimating apparatus according to claim 1, wherein the plurality of batteries are configured to be connected in series with each other.
A battery pack comprising the battery capacity estimating apparatus according to any one of claims 1 to 9.
A vehicle comprising the battery capacity estimating apparatus according to any one of claims 1 to 9.
A battery capacity estimating method comprising: a measurement step of measuring a pack capacity of a battery pack and a voltage of each of a plurality of batteries included in the battery pack during a charging-discharging process; a relative capacity ratio calculation step of calculating the relative capacity ratio among the plurality of batteries based on a voltage range of each of the plurality of batteries; and a capacity estimation step of estimating a capacity of each of the plurality of batteries based on the pack capacity and the relative capacity ratio.
A non-transitory computer-readable storage medium having stored therein a program for executing a battery capacity estimating method comprising: a measurement step of measuring a pack capacity of a battery pack and a voltage of each of a plurality of batteries included in the battery pack during a charging-discharging process; a relative capacity ratio calculation step of calculating the relative capacity ratio among the plurality of batteries based on a voltage range of each of the plurality of batteries; and a capacity estimation step of estimating a capacity of each of the plurality of batteries based on the pack capacity and the relative capacity ratio.

Description

TECHNICAL FIELD This application is based on and claims priority from Korean Patent Application No. 10-2024-0025269, filed on February 21, 2024, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. The present disclosure relates to a battery capacity estimating apparatus and method, and more specifically, to an apparatus and method for estimating the capacity of a battery. BACKGROUND Recently, as the demand for portable electronic products such as notebook computers, video cameras, and portable phones has rapidly increased, and as the development of electric vehicles, energy storage batteries, robots, and satellites has begun in earnest, researches on the high-performance batteries allowing repeated charging and discharging are being actively conducted. Currently, commercialized batteries include, for example, nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and lithium batteries. Among these, lithium batteries have received considerable attention due to their advantages including a substantially low memory effect to allow a high degree of freedom in charging and discharging, a very low self-discharging rate, and high energy density, as compared to the nickel-based batteries. Since a battery has a characteristic of degrading over time with use, it is necessary to accurately grasp the current state of the battery in order to diagnose (or predictively diagnose) the state (or lifespan) of the battery. However, after the battery is manufactured, it becomes challenging to disassemble and analyze the battery, making it difficult to accurately measure and diagnose the current state of the battery. Accordingly, there is a demand for a technology capable of more accurately estimating the current state of a battery using a non-destructive method. DISCLOSURE Technical Problem The present disclosure provides a battery capacity estimating apparatus and method for estimating the capacity of a battery using a non-destructive method. Various aspects of the present disclosure may be understood through the following description and will become more apparent from the embodiments of the present disclosure. In addition, it will be readily understood that various aspects of the present disclosure may be implemented by the means and combinations thereof as described in the claims. Technical Solution A battery capacity estimating apparatus according to an aspect of the present disclosure may include: a measurement unit configured to measure the pack capacity of a battery pack and the voltage of each of a plurality of batteries included in the battery pack during a charging-discharging process; and a control unit. The control unit is configured to: calculate the relative capacity ratio among the plurality of batteries based on the voltage range of each of the plurality of batteries; and estimate the capacity of each of the plurality of batteries based on the pack capacity and the relative capacity ratio. The control unit may be configured to: determine the voltage range of each of the plurality of batteries; adjust the determined plurality of voltage ranges to correspond to each other to calculate the change ratio of each of the plurality of batteries; and calculate the relative capacity ratio of each of the plurality of batteries based on the calculated plurality of change ratios. The control unit may be configured to: set one of the plurality of voltage ranges as a reference voltage range; and adjust the plurality of voltage ranges to correspond to the reference voltage range to calculate the plurality of change ratios. The control unit may be configured to: calculate a range value representing the size of each of the plurality of voltage ranges; and calculate the ratio of the range value of the reference voltage range to the range value of each of the plurality of voltage ranges to calculate the plurality of change ratios. The control unit may be configured to: set one of the plurality of change ratios as a reference change ratio; and calculate the relative capacity ratio of each of the plurality of batteries based on the plurality of change ratios and the reference change ratio. The control unit may be configured to calculate the ratio of the reference change ratio to each of the plurality of change ratios to calculate the relative capacity ratio of each of the plurality of batteries. The control unit may be configured to set the largest value among the plurality of change ratios as the reference change ratio. The control unit may be configured to estimate the capacity of each of the plurality of batteries by multiplying the pack capacity by the relative capacity ratio. The plurality of batteries may be configured to be connected in series with each other. A battery pack according to another aspect of the present disclosure may include the battery capacity estimating apparatus according to an aspect of the present disclosure. A vehi