Battery Management Pressure Sensing for Thermal Runaway Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing battery management systems struggle to reliably detect thermal runaway in high-voltage battery cells of electric vehicles due to the risk of measurement line damage from high temperatures, leading to delayed detection and potential fire hazards.

Innovation Solution

Incorporating a pressure sensor into the battery management system's electronic circuit, which captures pressure signals within the battery housing and sends them to a processor for analysis, allowing for rapid detection of thermal events without relying on potentially damaged measurement lines.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If temperature sensors and voltage sensors are used to monitor battery cells, then thermal runaway detection capability is improved, but the measurement lines are damaged by high temperatures leading to detection failure

Engineering Contradiction:
Improvethermal runaway detection reliabilityVSAvoidhigh temperature damage to measurement lines
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the electrical measurement system (temperature sensors and voltage sensors connected via measurement lines) with a mechanical pressure sensing system. The pressure sensor detects pressure changes in the battery housing caused by thermal runaway, eliminating the need for measurement lines that are vulnerable to high temperature damage.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If sensors are positioned close to battery cells for accurate monitoring, then detection precision is improved, but the components are exposed to high temperatures causing damage

Engineering Contradiction:
Improvethermal event detection precisionVSAvoidtemperature exposure of sensors and measurement lines
Core Design Contradiction:
Measurement precisionVSTemperature

Solution Approach 1:

The patent segments the sensing function from the battery cell proximity zone. Instead of placing sensors directly near the battery cells where temperatures exceed 1200°C, the pressure sensor is positioned in the battery housing at a safer location, while still detecting the pressure changes propagated from the thermal event.

Inventive Principle:
Principle #1Segmentation

3Reliability

If complex fire protection measures are implemented to protect measurement lines, then component reliability is improved, but device complexity and cost increase

Engineering Contradiction:
Improvemeasurement line protection reliabilityVSAvoidfire protection measures complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the vulnerable measurement lines and sensors from the high-temperature environment near battery cells. By using a pressure sensor that detects thermal runaway through pressure changes in the housing, the system eliminates the need for complex fire protection measures on measurement lines.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If traditional sensor systems are used, then temperature and voltage monitoring is achieved, but detection time is delayed due to signal processing inertia

Engineering Contradiction:
Improvethermal runaway detection capabilityVSAvoiddetection time delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent changes the detection parameter from temperature and voltage (which require complex signal processing and have inertia) to pressure changes. Pressure sensors can detect rapid pressure changes caused by thermal runaway almost instantaneously, significantly reducing detection time delay.

Inventive Principle:
Principle #35Parameter changes

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 solution enables quick and reliable detection of thermal runaway, reducing the risk of battery fires and allowing for timely warnings to vehicle occupants, while also eliminating the need for complex and costly fire protection measures for measurement lines.

Implementation Method 1

the electronic circuit additionally has at least one pressure sensor (14) designed to capture pressure signals in the battery housing (5)

Methodology Applied
Scientific EffectPressure detection:

Data Source

PatentUS12288852B2Battery management system for a high-voltage battery of a motor vehicle, high-voltage battery, and motor vehicle
Publication Date: 2025.04.29 BAYERISCHE MOTOREN WERKE AG
  • US12288852B2 patent drawing

AI summary

A battery management system for a high-voltage battery of a motor vehicle monitors battery cells of the high-voltage battery. The battery management system can be arranged in a battery housing of the high-voltage battery and has an electronic circuit which is arranged on a circuit carrier and has a processor and a communication interface for communication with at least one vehicle-side unit external to the high-voltage battery. The electronic circuit has at least one pressure sensor, which is designed to detect pressure signals in the battery housing and transmit same to the processor. The processor is designed to detect, on the basis of the transmitted pressure signals, a thermal runaway of at least one battery cell of the high-voltage battery, to generate a signal in the event that a thermal runaway is detected, and to provide the signal of the communication interface for transmission to the unit.