Secondary Battery Deterioration Assessment by Voltage-Section Feasibility

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Solution Overview

Problem

Existing methods for determining the deterioration degree of secondary batteries in a battery pack lack accuracy, especially when the variation in deterioration degree among batteries is small, and often require complex configurations.

Innovation Solution

A deterioration degree determination device that assesses battery characteristics based on voltage transitions in a predetermined voltage section, with a feasibility check to ensure accurate determination, using a simple configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple types of measurement values (voltage, current, temperature, etc.) are acquired and combined for comprehensive deterioration assessment, then the accuracy of deterioration degree determination is improved, but the device complexity and data processing burden increase

Engineering Contradiction:
Improvedeterioration degree determination accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the deterioration assessment into multiple independent measurement dimensions (voltage, current, temperature, impedance) that can be measured separately by dedicated sensors, then combines them through a processing unit. This segmentation allows each measurement system to remain simple while achieving comprehensive assessment accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates a universal deterioration determination system that can handle multiple types of measurement values through a single processing framework. The deterioration determination unit is designed to accept various measurement types and apply unified deterioration degree calculation methods, reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If frequent measurements are performed to capture real-time battery state changes, then the responsiveness and accuracy of deterioration monitoring is improved, but the energy consumption and measurement time increase

Engineering Contradiction:
Improvereal-time monitoring accuracyVSAvoidenergy consumption for measurement
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic measurement cycles where voltage, current, temperature, and impedance are measured at scheduled intervals rather than continuously. This periodic action captures real-time battery state changes while allowing the system to enter low-power states between measurements, reducing overall energy consumption.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent maintains continuous monitoring capability through periodic measurements that collectively provide real-time deterioration tracking. By using multiple measurement types at periodic intervals, the system achieves continuous useful information gathering without requiring all sensors to operate continuously, optimizing energy usage.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP4175005B1Deterioration degree determination device for secondary battery
Publication Date: 2026.04.15 DENSO CORP
  • EP4175005B1 patent drawingFigure 1
  • EP4175005B1 patent drawingFigure 2(a)~2(b)
  • EP4175005B1 patent drawingFigure 3~4

AI summary

A deterioration degree determination device (1) has a battery information acquisition unit (61), a feasibility determination unit (62), a battery characteristic acquisition unit (63), and a deterioration degree determination unit (65). The battery information acquisition unit (61) acquires battery information related to the secondary battery (21 to 26). The feasibility determination unit (62) determines feasibility of determination of the deterioration degree of each secondary battery (21 to 26) based on the battery information acquired by the battery information acquisition unit (61) and a feasibility determination reference prepared in advance. The battery characteristic acquisition unit (63) acquires a battery characteristic related to transition of a battery state in a predetermined voltage section for the secondary battery (21 to 26) for which determination of the deterioration degree is determined to be feasible by the feasibility determination unit (62). The deterioration degree determination unit (65) determines the deterioration degree of the secondary battery (21 to 26) for which the determination of the deterioration degree is determined to be feasible, based on the battery characteristic acquired by the battery characteristic acquisition unit (63) or a battery characteristic relationship value calculated based on the battery characteristic.