Thermistor Mounting for Battery Cell Temperature Sensing
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Solution Overview
Problem
High-power battery modules with co-packaged lithium-ion cells face challenges in accurately and reliably placing thermistors for temperature monitoring due to manufacturing difficulties with thermistor leads handling and routing, requiring an improved thermistor mounting arrangement for reliable thermal coupling.
Innovation Solution
A cell temperature sensing apparatus featuring a planar circuit board with openings for thermistors, a socket mechanically locked to the board, and an insert with a thermistor element and compressible member for resilient thermal contact, along with radial or surface-mount thermistors and flexible circuits for electrical coupling, simplifying installation and ensuring reliable thermal and electrical connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional thermistors with leads are used for temperature monitoring, then temperature sensing capability is achieved, but manufacturing difficulties arise due to lead handling and routing complexity
Solution Approach 1:
The thermistor assembly is segmented into modular components: a planar circuit board with integrated thermistor, a socket mounted on the battery cell, and a compressible connector. This segmentation allows each component to be manufactured and assembled separately, eliminating lead routing complexity while maintaining reliable thermal and electrical connections.
Solution Approach 2:
The traditional mechanical lead-based electrical connection is replaced with a planar circuit board that provides both thermal coupling and electrical connection through integrated traces. The compressible member provides mechanical pressure to ensure both thermal and electrical contact without requiring manual lead routing.
2Measurement precision
If thermistors are placed in contact with battery cell cases, then temperature measurement is enabled, but consistent thermal coupling is difficult to achieve in high-volume manufacturing
Solution Approach 1:
The thermistor is pre-mounted on the planar circuit board during board fabrication, and the socket is pre-installed on the battery cell. This preliminary preparation allows for consistent thermal coupling geometry to be established before final assembly, ensuring measurement precision while enabling rapid assembly in high-volume manufacturing.
Solution Approach 2:
The compressible member changes its physical state from uncompressed to compressed when installed, automatically adjusting the thermal contact pressure to optimize thermal coupling. This self-adjusting mechanism ensures consistent thermal contact without requiring precise manual positioning or adjustment during assembly.
3Ease of manufacture
If simple thermistor mounting is used, then manufacturing is easier, but reliable thermal coupling between thermistor and battery cell cannot be ensured
Solution Approach 1:
The compressible member provides a dynamic, resilient connection that automatically maintains optimal thermal and electrical contact pressure. This dynamic mechanism compensates for manufacturing tolerances and assembly variations, ensuring reliable thermal coupling while keeping the overall mounting process simple and suitable for automated assembly.
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
The solution ensures reliable thermal coupling, mechanical retention, and easy installation of thermistors, eliminating lead handling and routing issues, while providing accurate temperature sensing for battery cells.
Implementation Method 1
a compressible member compressed between said socket and the case of said battery cell to resiliently retain the thermistor in thermal proximity to said temperature sensing location
Implementation Method 2
an insert extending between a base of said socket and the temperature sensing location on the case of the battery cell. The insert includes a thermistor element in thermally proximity to said temperature sensing location
Data Source
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AI summary
A printed circuit board (14) supported over the top surface of a multi-cell battery module (10) for battery cell voltage and temperature monitoring has an array of openings (28) in alignment with selected battery cells (12) for receiving temperature-sensing units (16,18) that electrically couple with contacts (32) formed on the printed circuit board and resiliently engage the cases of the selected battery cells. Each such temperature-sensing unit (16,18) includes a printed circuit board mountable lamp socket (18a) and a lamp socket insert (18b) including a thermistor and a compressible element that maintains the thermistor in thermal proximity to the battery cell case when the temperature-sensing unit (16,18) is installed in a respective printed circuit board opening (28).