Battery Capacity Estimation Using Hysteresis Temperature Modeling

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Solution Overview

Problem

The estimation accuracy of the available total discharge capacity of batteries is low due to temperature sensor sampling points failing to cover opposite edges, leading to hysteresis in temperature collection and inaccurate capacity estimation.

Innovation Solution

A battery capacity estimation method that calculates a hysteresis coefficient and first temperature rise variation coefficient, updates a first estimated temperature using these coefficients and sensing temperature, and determines an estimated capacity based on preset reference parameters, using a hysteresis temperature to improve accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If temperature sensor sampling points are arranged throughout the battery pack, then temperature coverage is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improvetemperature measurement accuracyVSAvoidsensor arrangement complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a heat transfer model as an intermediary to bridge the gap between limited sensor measurements and actual battery temperature. The model uses thermal conductivity parameters and heat transfer equations to calculate true battery temperature from sensor readings, eliminating the need for dense sensor coverage while maintaining measurement accuracy.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical approach of increasing sensor quantity and distribution with a computational thermal model. Instead of physically placing more sensors throughout the battery pack, the system uses mathematical calculations based on heat transfer principles to infer temperatures at locations without direct sensors.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If temperature sensor sampling points are limited, then device complexity is reduced, but temperature measurement accuracy deteriorates due to hysteresis

Engineering Contradiction:

Improvesensor arrangement simplicityVSAvoidtemperature measurement accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary calculation of thermal conductivity parameters and pre-establishes heat transfer models before actual temperature measurement. By pre-characterizing the thermal properties of the battery pack structure and pre-calculating heat transfer coefficients, the system compensates for sensor placement limitations in advance, enabling accurate temperature estimation despite limited sensor coverage.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where sensor temperature readings are continuously fed into the thermal model, which then adjusts and refines the estimated battery temperature calculations. The model uses the sensor data as input, processes it through heat transfer equations, and outputs corrected temperature values that account for thermal hysteresis and spatial temperature gradients.

Inventive Principle:

Principle #23Feedback

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 method enhances the estimation accuracy of the available total discharge capacity by using hysteresis temperature, providing a more precise calculation compared to direct sensor temperature estimation.

Implementation Method 1

calculating a hysteresis coefficient corresponding to a current estimation period and calculating a first temperature rise variation coefficient corresponding to the current estimation period according to the hysteresis coefficient

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

the temperature of local points rises rapidly, while the temperature rise at the opposite edges of the battery is slower than that at the local points

Methodology Applied

Scientific EffectHeat transfer: Convection

Data Source

PatentUS20250370049A1Battery capacity estimation method, electronic device and storage medium

Publication Date: 2025.12.04 SUNWODA MOBILITY ENERGY TECHNOLOGY CO LTD

AI summary

A battery capacity estimation method, an electronic device and a storage medium are disclosed, which belong to the technical field of batteries. The method includes: calculating a hysteresis coefficient corresponding to a current estimation period and calculating a first temperature rise variation coefficient corresponding to the current estimation period according to the hysteresis coefficient, where the hysteresis coefficient represents a hysteresis relationship between an actual battery thermal power and an average battery thermal power per unit time; acquiring a first estimated temperature; updating the first estimated temperature according to the first temperature rise variation coefficient, the first estimated temperature and a sensing temperature; obtaining an estimated frozen capacity corresponding to the current estimation period according to the updated first estimated temperature and preset reference parameters; and determining an estimated capacity of a battery according to the estimated frozen capacity.