Battery Cell Controller Analog Timer for Reliable Balancing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing battery cell balancing systems using digital timers may fail to stop charge level adjustment operations optimally, especially in cases of stuck failures where continuous output occurs regardless of input/output signals, leading to potential over-discharge issues.

Innovation Solution

The implementation of an analog timer with a capacitor and discharge resistor circuit that sustains a voltage threshold for a predetermined time, allowing the cell controller to switch to low power consumption mode and stop balancing operations even if the analog timer fails, ensuring reliable termination of charge level adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a digital timer is used to control charge level adjustment operation, then the operation can be executed continuously with automatic timing, but the system cannot stop the operation with optimal timing when a stuck failure occurs

Engineering Contradiction:
Improveautomatic timing controlVSAvoidfailure to stop operation
Core Design Contradiction:
Extent of automationVSReliability

Solution Approach 1:

The patent introduces an intermediary mechanism (external timer control signal and monitoring circuit) that mediates between the digital timer and the charge level adjustment operation. When the digital timer fails, the external timer signal can override and stop the operation, preventing the reliability issue while maintaining automatic timing control through the primary digital timer.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If charge level adjustment operation continues without proper stopping mechanism, then automatic balancing can be maintained, but over-discharge may occur reducing battery safety

Engineering Contradiction:
Improvecontinuous balancing operationVSAvoidover-discharge risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent implements a feedback mechanism where the system continuously monitors the charge level adjustment operation and automatically stops it when termination conditions are met. The monitoring circuit provides feedback signals that trigger the stop command, ensuring the operation maintains productivity while preventing over-discharge through real-time condition assessment.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system takes preliminary anti-action by preparing the stopping mechanism in advance. The monitoring circuit is continuously ready to detect termination conditions and issue stop commands before over-discharge can occur. This preventive approach ensures that even if the digital timer fails, the operation will be stopped at the appropriate time, eliminating over-discharge risk while maintaining continuous balancing capability.

Inventive Principle:
Principle #9Preliminary anti-action

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 solution enables reliable stopping of charge level adjustments in battery cell balancing systems, even in the event of timer failures, preventing over-discharge and ensuring efficient battery management.

Implementation Method 1

an analog timer which includes a capacitor capable of accumulating and discharging electric energy

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

an analog timer which includes a capacitor capable of accumulating and discharging electric energy

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP2950420B1Cell controller and cell monitoring device
Publication Date: 2019.07.24 HITACHI AUTOMOTIVE SYST LTD
  • EP2950420B1 patent drawingFigure 1
  • EP2950420B1 patent drawingFigure 2
  • EP2950420B1 patent drawingFigure 3

AI summary

A cell controller in a battery-monitoring device that monitors an assembled battery having a single cell group or a plurality of cell groups, each made up with a plurality of battery cells connected in series, includes: a startup terminal to which a first discharge resistor is connected and a startup voltage is applied; and a cell-balancing unit that executes cell balancing operation in order to adjust charge levels of the plurality of battery cells during a time period through which the startup voltage remains equal to or greater than a predetermined voltage, wherein: the startup voltage is applied for a predetermined length of time by a first timer unit that includes a passive element capable of accumulating electric energy and capable of discharging electric energy to the startup terminal.