Battery Pack Thermistor Mounting for Accurate Cell Temperature Sensing
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Solution Overview
Problem
Existing battery packs with thermistors face challenges in accurately sensing the temperature of bare cells due to interference from the battery case, which can lead to reduced performance and reliability in high-output and high-voltage applications.
Innovation Solution
A battery pack design where a thermistor is firmly attached to the protection circuit module, positioned parallel to the bare cells, and electrically connected to transfer temperature measurements as a variable resistance signal, with an insulating film and adhesive members ensuring precise temperature sensing without case interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the thermistor is mounted on the protection circuit module to sense battery temperature, then temperature monitoring function is achieved, but the battery case interferes with the thermistor's sensing accuracy
Solution Approach 1:
The patent introduces an adhesive member as an intermediary between the thermistor and the protection circuit module. This adhesive member serves as a thermal conduit that transfers heat from the battery cells to the thermistor while electrically isolating the thermistor from the circuit module, thereby eliminating case interference and improving temperature sensing accuracy
Solution Approach 2:
The patent replaces the conventional direct electrical mounting method with a thermal coupling method using adhesive material. Instead of relying on electrical contact for heat transfer, the system uses the adhesive's thermal properties to conduct heat while providing electrical insulation, thus resolving the interference issue
2Measurement precision
If the thermistor is positioned close to the bare cells for accurate sensing, then temperature measurement precision improves, but the thermistor becomes vulnerable to mechanical damage and electrical interference
Solution Approach 1:
The protection circuit module serves as an intermediary structure that positions the thermistor in close proximity to the battery cells for accurate sensing while simultaneously providing mechanical protection and electrical isolation. The adhesive member further mediates the thermal coupling without creating direct electrical contact
Solution Approach 2:
The adhesive member acts as a flexible thin film that thermally couples the thermistor to the battery cells while allowing for mechanical flexibility and stress absorption, protecting the thermistor from mechanical damage during assembly and operation
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 design enhances the accuracy of temperature sensing for bare cells, improving the safety and performance of battery packs by preventing case-induced interference and ensuring reliable temperature monitoring.
Implementation Method 1
a thermistor provided to be parallel in the length direction of the protection circuit module between the bare cells and the protection circuit module so as to sense a temperature of the bare cells by measuring a variable resistance
Implementation Method 2
an insulating film that covers the temperature sensing element and the support portion
Data Source
AI summary
A battery pack includes a plurality of bare cells electrically connected in series or parallel to one another, and a protection circuit module provided with a thermistor. In the battery pack, the protection circuit module is electrically connected to the bare cells, and the thermistor is provided to be parallel in the length direction of the protection circuit module between the bare cells and the protection circuit module so as to measure a variable resistance by sensing a temperature of the bare cells and to transfer the measured resistance as an electrical signal to the protection circuit module.