Battery Charging Current Control Using Impedance Spectrum Feedback

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Solution Overview

Problem

Fast charging technologies increase battery temperature, leading to accelerated aging and safety risks due to unmonitored changes in battery internal state and chemical reactions, particularly in batteries connected in series or parallel.

Innovation Solution

A charging control method that monitors battery impedance parameters, using an electrochemical impedance spectrum data model to adjust charging current based on comparisons with preset values, ensuring safe and efficient charging by reducing or increasing current as needed to match the battery's internal state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If fast charge technology is used to increase charging power, then charging speed is improved, but battery temperature rises causing accelerated aging and safety risks

Engineering Contradiction:
Improvecharging speedVSAvoidbattery safety and life
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements a feedback mechanism by continuously monitoring battery impedance parameters during charging and comparing them with preset values from the electrochemical impedance spectrum data model. Based on the comparison results, the charging current is dynamically adjusted to prevent overheating and ensure battery safety while maintaining fast charging capability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent transforms the static charging current into a dynamic parameter that changes in real-time based on battery state. By continuously adjusting the charging current according to impedance monitoring results, the system adapts to the battery's changing internal state during charging, preventing temperature-related safety issues while maintaining high charging speed.

Inventive Principle:
Principle #15Dynamics

2Loss of time

If charging current is increased to reduce charging time, then productivity is improved, but temperature rise causes harmful effects on battery

Engineering Contradiction:
Improvecharging timeVSAvoidtemperature rise and heat loss
Core Design Contradiction:
Loss of timeVSObject-affected harmful factors

Solution Approach 1:

The system uses feedback control by monitoring impedance parameters and adjusting charging current accordingly. When impedance changes indicate rising temperature or adverse conditions, the charging current is reduced to minimize heat generation, thereby reducing harmful thermal effects while still achieving efficient charging.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the charging current parameter dynamically based on real-time impedance monitoring. By adjusting this key parameter according to battery state, the system optimizes the balance between charging speed and temperature control, minimizing harmful thermal effects during fast charging.

Inventive Principle:
Principle #35Parameter changes

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 effectively reduces safety risks and minimizes charging time by dynamically adjusting charging current based on battery impedance changes, ensuring battery safety and longevity.

Implementation Method 1

obtaining a present impedance value of an impedance parameter set of a battery, wherein the impedance parameter set includes at least one impedance parameter; determining, based on charging state information of the battery, a present index in an electrochemical impedance spectrum data model

Methodology Applied
Scientific EffectElectrochemical impedance spectrum:

Implementation Method 2

During fast charge, the current entering the battery will increase, causing an increased temperature of the battery due to heat loss

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP4645638A1Charging control method, terminal, computer readable medium
Publication Date: 2025.11.05 ZTE CORP
  • EP4645638A1 patent drawingFigure 1~2
  • EP4645638A1 patent drawingFigure 3~4
  • EP4645638A1 patent drawingFigure 5~7

AI summary

A charging control method comprises the steps: S1, obtaining current impedance values of a set of impedance parameters of a battery, wherein the set of impedance parameters comprises at least one impedance parameter; S2, determining a current index in an electrochemical impedance spectrum data model according to charging state information of the battery; S3, comparing the current impedance values with a preset impedance parameter value corresponding to the current index, wherein the electrochemical impedance spectrum data model comprises preset impedance parameter values of the set of impedance parameters corresponding to different indexes; and S4, determining a charging current according to a comparison result. According to the method, rapid charging can be implemented while the service life and safety of the battery are ensured. A terminal and a computer-readable medium are further included.