Starter Supercapacitor Backup for Battery-Failure Engine Restart

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Solution Overview

Problem

Vehicles powered by internal combustion engines face frequent battery failures, leading to immobilization and inconvenience, as the battery lifespan is shorter than the vehicle's and cannot supply enough energy to start the engine, necessitating regular replacements or towing.

Innovation Solution

Implementing a supercapacitor as an electrical energy storage system connected to the starter, which is charged by the starter in generator mode during engine operation, allowing the supercapacitor to power the starter when the battery fails, while the alternator recharges the battery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a battery is used to power the starter, then the engine can be started, but the battery fails after a limited lifespan leading to vehicle immobilization

Engineering Contradiction:
Improvevehicle starting reliabilityVSAvoidbattery lifespan
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The electrical energy storage function is segmented into two distinct systems: a battery for sustained energy storage and a supercapacitor for high-power impulse delivery. This segmentation allows each component to operate within its optimal performance range, with the supercapacitor handling the high-current starter demands without degradation, while the battery provides long-term energy supply.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The supercapacitor acts as an intermediary between the battery and the starter motor. It buffers the high-current demands of the starter, preventing direct stress on the battery. The control unit mediates the energy flow, directing the starter to draw power from the supercapacitor during cranking operations, thereby protecting the battery from deep discharge cycles that reduce lifespan.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If the battery is used to power the starter during engine starting, then the starter can operate, but the battery discharges and requires recharging or replacement

Engineering Contradiction:
Improvestarter powerVSAvoidbattery energy consumption
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The supercapacitor is pre-charged during engine operation when the alternator generates electrical energy. This preliminary energy storage ensures that when the starter requires high power, the supercapacitor is already charged and ready to deliver the necessary current impulse without depleting the battery.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses its own operational components to recharge the energy storage system. The alternator, which generates electricity during engine operation, automatically recharges the supercapacitor after the engine has been started by it, creating a self-sustaining cycle that requires no external intervention.

Inventive Principle:
Principle #25Self-service

3Reliability

If a battery/capacitor setup is implemented, then the vehicle can start after battery failure, but the system complexity increases

Engineering Contradiction:
Improveengine starting reliabilityVSAvoidelectrical system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The supercapacitor module serves multiple functions: it provides high-power impulse to the starter during engine cranking, acts as a buffer to protect the battery from high-current stress, and can be recharged from either the alternator or external sources. This multi-functionality justifies the added component by delivering several benefits simultaneously.

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

Solution Approach 2:

The control unit continuously monitors the state of charge of both the battery and supercapacitor, as well as the starter current demand. Based on this feedback, it dynamically manages power distribution, directing the starter to draw from the supercapacitor when available and coordinating recharging operations to maintain optimal system state.

Inventive Principle:
Principle #23Feedback

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

Ensures reliable engine starting after battery failure without needing a replacement, extending vehicle operation and reducing immobilization risks, with the supercapacitor providing quick power and a longer lifespan than batteries, and simplifying manufacturing by using existing components.

Implementation Method 1

an electrical energy storage system, connected to the starter and to the charger, and distinct from the battery

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

an alternator, connected to the internal combustion engine and to the battery and configured to charge the battery

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

a starter, connected to the internal combustion engine and to the battery and configured to start the internal combustion engine

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP4424984B1Method for operating a vehicle and vehicle operated by such a method
Publication Date: 2025.11.19 VOLVO TRUCK CORP
  • EP4424984B1 patent drawingFigure 1
  • EP4424984B1 patent drawingFigure 2
  • EP4424984B1 patent drawingFigure 3

AI summary

A vehicle comprises an internal combustion engine, a battery, an alternator, a starter, configured to start the internal combustion engine, a charger, distinct from the battery, and an electrical energy storage system, connected to the starter and to the charger, and distinct from the battery. To allow the engine to be started in case of a battery failure, a method (100) for operating the vehicle comprises: - starting (110) the internal combustion engine, - measuring (120) a state of charge of the battery, - comparing (130) the measured state of charge with a predetermined threshold value, - if the measured state of charge is lower than the predetermined threshold value: o charging (140) the electrical energy storage system with the charger, then o starting (160) the internal combustion engine with the starter, by powering the starter with the electrical energy storage system, when restarting the internal combustion engine is required.