Battery Charging Circuit Wake-Up Control to Prevent Overcharge

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Solution Overview

Problem

Battery overcharge can lead to serious safety accidents, particularly in vehicles using lead-acid and lithium batteries, where closing the lithium battery charging circuit during vehicle startup can cause thermal runaway and safety hazards.

Innovation Solution

A circuit control method that includes acquiring an apparatus wake-up signal and determining power source terminal voltage and change rate conditions to safely control the charging circuit, ensuring it is only turned on when specific thresholds and conditions are met to prevent overcharge and thermal runaway.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the charging circuit is turned on during vehicle startup, then the battery can be charged, but the battery may experience overcharge and thermal runaway

Engineering Contradiction:
Improvecharging efficiencyVSAvoidbattery safety
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies preliminary action by checking the wake-up signal status before enabling the charging circuit. The controller determines whether the vehicle has completed startup before activating charging, preventing overcharge conditions. This advance verification ensures the battery is only charged when the vehicle is fully operational, resolving the contradiction between charging efficiency and battery safety.

Inventive Principle:
Principle #10Preliminary action

2Use of energy by moving object

If the charging circuit is turned on early to enable battery charging, then energy utilization is improved, but the switch may stick due to large current discharge

Engineering Contradiction:
Improvecharging availabilityVSAvoidswitch reliability
Core Design Contradiction:
Use of energy by moving objectVSEase of operation

Solution Approach 1:

The patent implements preliminary action by verifying the wake-up signal condition before closing the charging circuit switch. This ensures the vehicle startup is complete and the system is ready to handle charging current, preventing switch sticking caused by premature high current discharge. The switch is only activated when conditions are confirmed safe, maintaining both charging availability and switch reliability.

Inventive Principle:
Principle #10Preliminary action

3Speed

If the charging circuit is activated without wake-up signal verification, then charging speed is improved, but overcharge and thermal runaway risks increase

Engineering Contradiction:
Improvecharging speedVSAvoidthermal runaway risk
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent applies feedback by continuously monitoring the wake-up signal status and using this information to control the charging circuit. The controller receives feedback about the vehicle startup state and adjusts charging activation accordingly. This feedback mechanism ensures charging only begins when the vehicle is fully started, preventing overcharge and thermal runaway while allowing rapid charging once conditions are met.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4270591B1Circuit control method, battery and controller and management system thereof, and electric apparatus
Publication Date: 2025.11.19 CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED
  • EP4270591B1 patent drawingFigure 1
  • EP4270591B1 patent drawingFigure 2~3
  • EP4270591B1 patent drawingFigure 4

AI summary

Embodiments of the present application relate to the technical field of batteries, and provide a circuit control method, a battery controller, a battery management system, a battery, an electric apparatus, and a vehicle. The circuit control method comprises: obtaining an apparatus wake-up signal; determining whether the power supply terminal voltage of the charging circuit of a battery on an apparatus is greater than a first threshold, and whether a rate of change within a first duration is less than a second threshold, wherein the charging circuit is a circuit connecting the battery on the apparatus to a power generator, and the power supply terminal voltage is the output voltage of the power generator; and in the case that the power supply terminal voltage of the charging circuit of the battery on the apparatus is greater than the first threshold, and the rate of change within the first duration is less than the second threshold, issuing a first instruction, so that the charging circuit is turned on. According to the described mode, the present application can avoid that the charging circuit of the battery is turned on when the apparatus is not started, and when the apparatus is subsequently started, a lithium battery is over-charged to cause the thermal runaway of the battery, thereby improving the safety of the battery.