Battery Fast-Charging Current Ramping for Overheat Control

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Solution Overview

Problem

High-current high-power fast charging can cause rapid battery temperature rises, leading to potential device overheating and user experience issues due to excessive fluctuations in charging current adjustments.

Innovation Solution

A charging control method that monitors real-time battery temperature and reduces the charging current level-by-level at increasing rates when the temperature exceeds a threshold, switching back to maximum current when safe, to prevent overheating and stabilize charging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high-current high-power fast charging is applied, then charging speed and power are improved, but battery temperature rises rapidly causing overheating risks

Engineering Contradiction:
Improvecharging speedVSAvoidbattery temperature
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The charging current is made dynamic rather than fixed, adjusting in real-time based on battery temperature conditions. The system switches between first charging current (higher) and second charging current (lower) depending on whether temperature exceeds the threshold, optimizing both charging speed and thermal management

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The charging current parameter is changed based on temperature conditions. When battery temperature exceeds the threshold, the system changes from high current to low current charging, and vice versa, thereby controlling temperature while maintaining efficient charging

Inventive Principle:
Principle #35Parameter changes

2Temperature

If charging current is reduced to control temperature, then temperature rise is alleviated, but charging rate decreases

Engineering Contradiction:
Improvebattery temperature controlVSAvoidcharging rate
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The charging current is applied periodically in alternating phases of high current and low current. The system switches between first charging current and second charging current based on temperature threshold conditions, creating a periodic charging pattern that maintains both thermal safety and charging efficiency

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The charging process continues without interruption, switching between different current levels rather than stopping. This ensures continuous energy transfer to the battery while managing temperature, maintaining productive action throughout the charging cycle

Inventive Principle:
Principle #20Continuity of useful action

3Measurement precision

If charging current is adjusted frequently to respond to temperature changes, then temperature control precision is improved, but charging current fluctuations increase causing instability

Engineering Contradiction:
Improvetemperature control precisionVSAvoidcharging current stability
Core Design Contradiction:
Measurement precisionVSStability of the object's composition

Solution Approach 1:

The charging current is segmented into distinct levels (first charging current and second charging current) rather than continuous adjustment. This segmentation provides stable, discrete current states that reduce fluctuation while maintaining precise temperature control through threshold-based switching

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3813223B1Charging control method, device and storage medium
Publication Date: 2024.08.28 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP3813223B1 patent drawingFigure 1
  • EP3813223B1 patent drawingFigure 2
  • EP3813223B1 patent drawingFigure 3

AI summary

A charging control method includes: monitoring a real-time temperature of the battery during charging a battery with a first real-time charging current (S11); reducing the first real-time charging current to a second real-time charging current at a specified current reduction rate, when the real-time temperature of the battery is greater than a first temperature threshold (S12); and charging the battery according to the second real-time charging current (S13). As such, the temperature rise problem during high-current high-power fast charging can be alleviated, and excessive fluctuations due to instantaneous current adjustment can be prevented from affecting the charging rate thereby improving user experience.