Battery Pack Temperature Comparison for Abnormality Source Detection

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Solution Overview

Problem

Existing battery systems struggle to accurately distinguish between temperature increases caused by external environmental changes and malfunctions within the battery pack, leading to uncertainties in determining the root cause of abnormal temperature rises.

Innovation Solution

A battery system equipped with multiple temperature sensors (thermistors) that detect both the housing and individual battery cell temperatures, comparing the rates of temperature increase to differentiate between external environmental changes and internal malfunctions, with additional sensors positioned to minimize gas interference and facilitate easy assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single temperature sensor is used to detect battery cell temperature, then the device complexity is reduced, but the measurement precision and ability to distinguish between external and internal temperature increases deteriorates

Engineering Contradiction:

Improveaccuracy of determining temperature increase causeVSAvoidnumber of temperature sensors

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The temperature monitoring function is segmented into multiple independent sensors positioned at different locations: one sensor detects the temperature of the housing (external environment), while another sensor detects the temperature inside the housing near the battery cell. This segmentation allows the system to compare temperature increases at different locations to determine whether the cause is external or internal, thereby resolving the contradiction between measurement precision and device complexity.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If the first detection device is positioned close to the battery cell to detect internal temperature, then the measurement precision of internal temperature increases, but the detection becomes affected by gas discharge from the battery cell

Engineering Contradiction:

Improveaccuracy of internal temperature detectionVSAvoidgas discharge interference with temperature detection

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an insulating plate as an intermediary component between the battery cell and the first detection device. This insulating plate serves as a mediator that thermally couples the detection device to the battery cell environment while physically separating them, allowing the detection device to monitor internal temperature increases without being directly exposed to harmful gas discharge from the battery cell.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Measurement precision

If multiple temperature sensors and insulating plates are added to improve detection accuracy, then the measurement precision improves, but the ease of manufacture and assembly deteriorates

Engineering Contradiction:

Improveaccuracy of temperature increase cause determinationVSAvoidassembly complexity of battery system

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The insulating plate is designed to combine multiple functions into a single component: it provides thermal insulation, serves as a mounting structure for the first detection device, and facilitates heat transfer from the battery cell to the detection device. By merging these functions into one integrated component, the patent improves measurement precision while minimizing the increase in assembly complexity.

Inventive Principle:

Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables precise determination of the cause of temperature increases, distinguishing between external and internal factors with high accuracy, thereby improving safety and reliability of battery systems.

Implementation Method 1

a first detection device that detects a first temperature indicating a temperature of the housing

Methodology Applied

Scientific EffectTemperature detection: Thermistor

Implementation Method 2

a second detection device that detects a second temperature indicating a temperature in the housing

Methodology Applied

Scientific EffectTemperature detection: Thermistor

Implementation Method 3

a first control device that compares a result of detection by the first detection device with a result of detection by the second detection device to determine whether a temperature increase in the battery cell is due to a change in an external environment of the housing or due to a malfunction in the battery cell

Methodology Applied

Scientific EffectTemperature comparison:

Data Source

PatentEP4703179A1Abnormality determination system, vehicle, abnormality determination method, and server

Publication Date: 2026.03.04 TOYOTA JIDOSHA KK

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AI summary

An abnormality determination system includes: a battery pack (100); a first acquisition device (351) that acquires a first temperature indicating a temperature of a first region (361) of the battery pack; a second acquisition device (354) that acquires a second temperature indicating a temperature of a second region (364) different from the first region (361); and a control device (402) that determines whether an abnormality has occurred inside or outside the battery pack (100) using information about a history of the first temperature and a history of the second temperature.