Battery Pack Discharge Control via Ambient Temperature and Voltage Monitoring

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Solution Overview

Problem

Existing battery pack technologies do not effectively manage discharge processes in both high temperature and normal temperature environments, leading to potential battery degradation and swelling issues.

Innovation Solution

A method and system for controlling battery pack discharge by measuring ambient temperature and voltage, performing first and second discharge processes based on predetermined temperature and voltage thresholds, using a control section to manage discharge through a discharge line with a positive line, negative line, and resistor configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a bi-metal switch is used to discharge the battery in high temperature conditions, then the battery can be discharged in high temperature environment, but the size of the battery pack is increased

Engineering Contradiction:
Improvebattery discharge capability in high temperatureVSAvoidbattery pack size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent replaces the mechanical bi-metal switch with an electronic control system comprising a control circuit and switching device. The control circuit monitors temperature and voltage parameters electronically, and the switching device (such as a transistor or MOSFET) replaces the mechanical bi-metal switch to enable discharge. This substitution eliminates the need for thermal expansion-based mechanical switching, maintaining high temperature discharge capability while significantly reducing the battery pack size.

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

2Reliability

If discharge circuitry is added to enable discharge in high temperature environment, then the battery can be discharged in high temperature conditions, but the device complexity is increased

Engineering Contradiction:
Improvebattery discharge capability in high temperatureVSAvoiddischarge circuitry complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control circuit is designed to perform multiple functions: it monitors both temperature and voltage parameters, determines discharge conditions based on predetermined thresholds, controls the switching device to enable or disable discharge, and can operate in both high temperature and normal temperature environments. By integrating these multiple functions into a single control system, the patent avoids the need for separate dedicated circuits for each function, thereby reducing overall device complexity while maintaining reliable high temperature discharge capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of manufacture

If the battery is not discharged in normal temperature environment, then the battery can be used without additional discharge control, but the battery performance is lowered due to swelling or gas generation

Engineering Contradiction:
Improvesimplicity of battery usageVSAvoidbattery performance maintenance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The control circuit continuously monitors the battery's temperature and voltage parameters and compares them against predetermined thresholds. When the battery is in a normal temperature environment but exhibits high voltage indicating overcharge or excessive energy accumulation, the control circuit detects this condition and automatically activates the discharge function. This feedback mechanism ensures the battery is discharged as needed to prevent swelling and gas generation, maintaining battery performance while requiring no special user action or complex manual intervention.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2587582B1Method of controlling discharge, battery pack, electrical storage system, electronic apparatus, electric vehicle and power system
Publication Date: 2017.11.08 MURATA MFG CO LTD
  • EP2587582B1 patent drawingFigure 1
  • EP2587582B1 patent drawingFigure 2
  • EP2587582B1 patent drawingFigure 3

AI summary

A method of controlling discharge in a battery pack, including: measuring an ambient temperature of a battery cell and a voltage of the battery cell; a first discharge processing of discharging the battery cell until the voltage of the battery cell becomes a second voltage lower than a first voltage when the ambient temperature is higher than a first predetermined temperature and the voltage of the battery cell is higher than the first voltage; and a second discharge processing of discharging the battery cell until the voltage of the electrical battery cell becomes a fourth voltage lower than a third voltage when the ambient temperature is lower than the first predetermined temperature and the voltage of the battery cell is higher than the third voltage.