Single Wire Battery Pack Identification via Transient Response

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Solution Overview

Problem

Conventional battery charging methods require additional connection points or mechanical features, increasing cost, complexity, and size, and often rely on microprocessors or controllers to identify battery types, which are not cost-effective for all applications.

Innovation Solution

A method that determines the battery type by measuring the transient response to a signal applied across the battery terminals, using a lookup table to identify the battery type and adjust the charging current, eliminating the need for microprocessors and additional pins by utilizing a thermistor and capacitor in the charger to infer temperature and type from a single shared connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional battery identification techniques (SMBus, internal ID resistor, mechanical features) are used, then battery type identification accuracy is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvebattery type identification accuracyVSAvoidcharger circuit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the identification function from complex microprocessor-based systems and implements it through a simple RC time constant measurement circuit. By measuring the charging current transient response and extracting the time constant parameter, the system identifies battery type without requiring SMBus communication hardware, internal ID resistors, or mechanical identification features.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces expensive microprocessors and communication interfaces with inexpensive passive components (resistors and capacitors) for battery identification. The identification circuit uses only basic RC timing components that are significantly cheaper than microprocessor-based solutions, making the charger cost-effective for mass consumption applications.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Adaptability or versatility

If additional connection points or mechanical features are added for battery identification, then battery type identification capability is improved, but manufacturing cost and device size increase

Engineering Contradiction:
Improvebattery type identification capabilityVSAvoidmanufacturing cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent makes the existing charging connection points serve dual functions: both power transfer and battery identification. The same terminals used for charging also carry the identification signal, eliminating the need for separate identification contacts. This universal approach allows a single charger design to handle multiple battery types without additional mechanical features or connection points.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the power connection and identification function into a single integrated system. The charging current path itself is used to carry the identification information through transient response characteristics, combining what were previously separate functions into one unified process that reduces manufacturing complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If microprocessors are used for battery identification and charging control, then charging control precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvecharging control precisionVSAvoidcontroller complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the electronic/microprocessor-based control system with a passive RC timing circuit for battery identification. Instead of using microprocessors to measure and analyze transient responses, the system uses natural RC time constant characteristics of the battery-charger circuit to automatically identify battery type and trigger appropriate charging profiles.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent enables the charging circuit to automatically identify battery type and select appropriate charging parameters without microprocessor intervention. The RC time constant measurement and battery type determination happen automatically through the circuit's natural response characteristics, making the system self-identifying and self-configuring.

Inventive Principle:
Principle #25Self-service

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 approach allows for accurate identification of battery chemistry and temperature monitoring without extra pins or microprocessors, enabling universal charging of various battery types while maintaining accuracy in thermistor resistance measurement, thus reducing costs and complexity.

Implementation Method 1

The battery pack includes a thermistor having one end coupled to a first terminal and second end coupled to a second terminal

Methodology Applied
Scientific EffectThermistor: Thermistor

Implementation Method 2

A capacitor is coupled to the second terminal of the battery pack and the reference terminal in parallel with the thermistor

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP2659542B1Single wire battery pack temperature and identification method
Publication Date: 2020.07.22 DURACELL US OPERATIONS INC
  • EP2659542B1 patent drawingFigure 1
  • EP2659542B1 patent drawingFigure 2
  • EP2659542B1 patent drawingFigure 3

AI summary

Disclosed are techniques for identifying battery pack types and by inference battery chemistries by measuring a transient response of the battery pack to signal applied to the battery pack.