Battery Cell Temperature Estimation Using Gas Gauge Heat Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional systems for estimating battery cell temperature are either expensive due to the use of temperature sensors or inaccurate and error-prone when inferring temperature based on other characteristics.
Innovation Solution
A battery management system that uses processing circuitry to determine an estimated battery cell temperature through models incorporating battery voltage, open-circuit voltage, current measurements, and gas gauge temperature, reducing the need for explicit temperature sensors and improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a battery cell temperature sensor is used to detect the battery cell temperature, then the temperature measurement accuracy is improved, but the cost increases and the battery volume increases
Solution Approach 1:
The patent introduces a gas gauge temperature sensor as an intermediary component that indirectly measures battery cell temperature through heat transfer modeling. Instead of placing a temperature sensor directly on the battery cell, the system uses a temperature sensor in the gas gauge and mathematical models (heat generation models and heat transfer models) to estimate the battery cell temperature. This intermediary approach avoids the need for expensive and space-consuming direct temperature sensors while maintaining measurement accuracy.
Solution Approach 2:
The patent replaces the direct mechanical/physical temperature sensing system with a computational modeling system. Instead of using a temperature sensor in direct thermal contact with the battery cell (mechanical thermal coupling), the system uses electrical measurements (voltage, current) combined with thermal modeling algorithms to calculate temperature. This substitution of physical measurement with computational estimation reduces hardware complexity, cost, and volume.
2Temperature
If traditional temperature sensing methods are used, then temperature measurement is achieved, but the energy density of the battery decreases due to increased volume
Solution Approach 1:
The patent extracts the temperature sensing function from the battery cell structure itself and relocates it to the gas gauge system. By removing the need for a dedicated temperature sensor on or near the battery cell, the battery's active material volume can be maximized without compromise for temperature monitoring, thereby preserving energy density.
3Reliability
If battery cell temperature is inferred based on various characteristics in traditional systems, then the cost is reduced, but the accuracy and reliability of temperature estimation deteriorates
Solution Approach 1:
The patent implements a feedback-based temperature estimation system where the gas gauge temperature sensor continuously monitors temperature, and this measurement feeds into heat transfer models that are continuously updated based on battery operating conditions (voltage, current, state of charge). The system uses feedback from multiple sources (electrical measurements and thermal measurements) to continuously refine the temperature estimation, improving accuracy over simple one-time inference methods.
Solution Approach 2:
The patent creates a composite estimation approach by combining multiple types of data (electrical measurements of voltage and current, gas gauge temperature sensor readings) with multiple mathematical models (heat generation models, heat transfer models) to produce a unified temperature estimation. This composite method leverages the strengths of different measurement and modeling approaches to achieve higher accuracy than any single method alone.
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 approach reduces costs, minimizes battery volume, and enhances energy density while providing a more accurate estimation of battery cell temperature.
Implementation Method 1
During discharge and/or recharging, the battery cell may produce heat that can affect characteristics (e.g., performance, lifespan, or structure) of the battery and/or the electric device
Implementation Method 2
a battery and gas gauge heat transfer model that receives a fourth input indicative of a gas gauge temperature measurement
Data Source
AI summary
A battery includes a battery cell and processing circuitry. The processing circuitry is configured to determine an estimated temperature of the battery cell as a function of various models. The models include a battery cell heat generation model that receives a first input indicative of a battery voltage measurement, a second input indicative of a voltage corresponding to a battery open-circuit voltage (OCV) model, and a third input indicative of a battery current measurement. The models also include a gas gauge and system heat generation model that receives the third input. The models also include a battery and gas gauge heat transfer model that receives a fourth input indicative of a gas gauge temperature measurement.