Battery Cell Temperature Sensor Self-Heating Contact Test
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Solution Overview
Problem
Existing methods for testing the thermal contact between temperature sensors and battery cells in battery modules are manual, expensive, and lack automation, which is inadequate for ensuring accurate temperature measurements required for functional safety in automotive applications.
Innovation Solution
A testing method and circuit that measures the temperature differences of a thermistor-based temperature sensor before, during, and after heating to determine the thermal contact with battery cells, allowing for automated and precise assessment of thermal coupling without additional sensors, using a driving circuit and a testing circuit with a NTC thermistor and a measuring head for mechanical contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If manual testing methods are used for thermal contact verification, then testing can be performed, but the process is expensive and lacks automation
Solution Approach 1:
The temperature sensor performs self-testing by utilizing its own heating capability to generate test heat and its own temperature measurement capability to detect thermal contact quality, eliminating the need for external test equipment and manual intervention
Solution Approach 2:
The temperature sensor is designed with multi-functionality, serving both as a temperature measurement device and as a self-test device, by integrating heating elements and temperature sensing capabilities within the same component
2Measurement precision
If additional sensors are added for testing thermal contact, then measurement accuracy improves, but device complexity increases
Solution Approach 1:
The temperature sensor uses its own temperature sensing capability to measure the thermal contact quality by detecting temperature changes in its own housing caused by heat transfer from the battery cell, eliminating the need for additional measurement sensors
Solution Approach 2:
The testing function is extracted from a separate testing system and integrated into the temperature sensor itself, allowing the sensor to perform self-diagnosis of its thermal contact condition without requiring external testing equipment
3Manufacturing precision
If existing manual testing methods are used, then thermal contact can be assessed, but the process is time-consuming and lacks precision
Solution Approach 1:
The testing circuit periodically activates the heating element to generate test heat and measures the resulting temperature changes at predetermined time intervals, enabling automated and precise thermal contact assessment without manual intervention
Solution Approach 2:
The testing circuit continuously monitors temperature changes in the sensor housing and uses this feedback information to automatically evaluate thermal contact quality, providing precise measurement results without requiring manual assessment
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 reliable and automated determination of thermal contact between temperature sensors and battery cells, ensuring accurate temperature measurements and improving safety by reducing manufacturing costs and complexity.
Implementation Method 1
A testing method and circuit that measures the temperature differences of a thermistor-based temperature sensor
Implementation Method 2
measures the temperature differences of a thermistor-based temperature sensor before, during, and after heating
Data Source
AI summary
A testing method for a thermal contact between a temperature sensor and a battery cell of a battery module, includes measuring a temperature T1 of the temperature sensor at a time point t1, heating the temperature sensor for a defined time (t2−t1) and/or (t3−t1), measuring a temperature T2 of the temperature sensor at a time point t2 and/or a temperature T3 of the temperature sensor at a time point t3, and determining the thermal contact between the temperature sensor and the battery cell based on at least one of the temperature differences ΔT2,1=(T2−T1), ΔT3,1=(T3−T1) and ΔT3,2=(T3−T2) and a heat transfer coefficient determined thereby. Also, a testing circuit for a temperature sensor of a battery module includes a thermistor with a first node connected to a first supply voltage and a second node connected to ground, a switch interconnected between the first node of the thermistor and a second supply voltage, and an analog-to-digital converter connected in parallel to the thermistor. Also, a cell supervision circuit for a battery module including a circuit carrier, a testing circuit, and a temperature sensor surface mounted to the circuit carrier and having a measuring head with a thermistor configured to be brought into thermal contact with a battery cell of the battery module.