Battery Exhaust Valve Opening Detection from Temperature Rise Rate

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Solution Overview

Problem

Existing power supply devices struggle to accurately and quickly detect the opening of an exhaust valve due to fluctuations in battery temperature caused by ambient conditions and noise interference, making it difficult to reliably prevent battery rupture.

Innovation Solution

The device employs multiple temperature sensors to detect the rate of temperature rise (ΔT/Δt) and high temperature time (t1) to determine the opening of the exhaust valve, using set values to differentiate between noise-induced fluctuations and actual valve openings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If temperature detection is used to determine exhaust valve opening, then the valve opening can be detected, but the detection accuracy is reduced due to temperature fluctuations from ambient conditions and noise interference

Engineering Contradiction:
Improvevalve opening detection reliabilityVSAvoidtemperature measurement precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent changes the detection parameter from absolute temperature to temperature change rate (ΔT/Δt). By monitoring how quickly the temperature rises rather than the temperature itself, the system can distinguish between normal temperature fluctuations and the rapid temperature increase caused by exhaust valve opening, thereby improving detection reliability while maintaining measurement precision

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces dynamic thresholds for temperature change rate that adapt to different operating conditions. Instead of using a fixed temperature threshold, the system uses a dynamic threshold for dT/dt that can accommodate ambient temperature variations and noise, allowing reliable detection across different conditions without sacrificing measurement precision

Inventive Principle:
Principle #15Dynamics

2Reliability

If temperature detection is used to determine exhaust valve opening, then the valve opening can be detected, but the detection speed is reduced due to noise interference requiring additional filtering

Engineering Contradiction:
Improvevalve opening detection reliabilityVSAvoiddetection speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

By detecting temperature change rate (ΔT/Δt) instead of absolute temperature, the system can identify valve opening events more quickly. The rapid temperature spike causes a distinctive change rate pattern that stands out from noise, enabling faster detection without requiring extensive noise filtering that would slow down the response

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent allows the detection system to skip through noise interference by using a high-pass filtering approach on the temperature signal. By focusing on the rate of change rather than the absolute value, the system rushes through the noisy baseline and quickly identifies the characteristic rapid temperature increase of valve opening, improving detection speed while maintaining reliability

Inventive Principle:
Principle #21Skipping (Rushing through)

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

This method allows for precise and rapid detection of the exhaust valve opening, ignoring noise interference and ensuring accurate detection even with temperature fluctuations, thereby preventing battery damage.

Implementation Method 1

a temperature sensor configured to detect a temperature in the case

Methodology Applied
Scientific EffectTemperature detection: Thermal Radiation

Data Source

PatentEP3787096B1Power supply device, and method for detecting opening of exhaust valve of power supply device
Publication Date: 2026.03.11 PANASONIC ENERGY CO LTD
  • EP3787096B1 patent drawingFigure 1
  • EP3787096B1 patent drawingFigure 2
  • EP3787096B1 patent drawingFigure 3~4

AI summary

Disclosed is a power supply device including a battery having an exhaust valve that opens when an internal pressure becomes higher than a set pressure, the battery being housed in a case, a temperature sensor that detects a temperature in the case, and a detection circuit that detects opening of the exhaust valve at a detected temperature detected by the temperature sensor. In this power supply device, the detection circuit detects that a high temperature time (t1) from a timing at which a rate of rise (ΔT/Δt) of the temperature detected by the temperature sensor is higher than a rise rate set value and exceeds the rise rate set value to a timing at which the detected temperature falls to less than or equal to a reference temperature is longer than a high temperature time set value, and detects the opening of the exhaust valve.