EV Range Extender Battery Integration for Fast Parallel Charging

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Electric vehicles face range anxiety due to limited battery capacity, especially in high-demand situations, and existing charging infrastructure is inadequate in some regions, leading to concerns about frequent charging breaks.

Innovation Solution

Integration of a secondary battery system, or range extender, with power conversion systems and control strategies to manage multiple battery packs, including SOE balancing and OCV matching, to optimize energy distribution and facilitate high-speed charging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If the battery pack capacity is increased to extend vehicle range, then the driving range is improved, but the vehicle weight and cost increase

Engineering Contradiction:
Improvedriving rangeVSAvoidvehicle weight
Core Design Contradiction:
Duration of action of moving objectVSWeight of moving object

Solution Approach 1:

The patent divides the energy storage system into two separate battery packs: a main battery pack for primary energy storage and an auxiliary battery pack for supplemental range extension. This segmentation allows the vehicle to achieve extended range without requiring a single oversized battery pack, thereby reducing overall weight and cost while maintaining the ability to extend driving range when needed

Inventive Principle:
Principle #1Segmentation

2Duration of action of moving object

If a range extender is integrated into the EV powertrain, then the driving range is extended, but the device complexity increases

Engineering Contradiction:
Improvedriving rangeVSAvoidpowertrain complexity
Core Design Contradiction:
Duration of action of moving objectVSDevice complexity

Solution Approach 1:

The auxiliary battery pack is designed with multi-functionality to reduce overall system complexity. It can operate in multiple modes: providing supplemental power during driving, serving as a mobile charging source when connected to external power, and being independently charged from the main battery pack. This universal design consolidates functions that would otherwise require separate systems

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

Solution Approach 2:

The system implements self-service capabilities where the auxiliary battery pack can be charged from the main battery pack without external intervention, and can also serve as a charging source for the main battery pack when connected to external power. This bidirectional charging capability eliminates the need for complex external charging infrastructure and reduces system complexity

Inventive Principle:
Principle #25Self-service

3Ease of operation

If the auxiliary battery pack is always connected to the main battery pack, then energy management is simplified, but charging time increases during high-speed charging

Engineering Contradiction:
Improveenergy managementVSAvoidcharging time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The connection between the auxiliary and main battery packs is made dynamic rather than static. The system can automatically disconnect the auxiliary battery pack from the main battery pack during high-speed charging operations, allowing the main battery pack to be charged at maximum rate without being limited by the auxiliary pack's charging capabilities. This dynamic reconfiguration optimizes charging time while maintaining simplified energy management during normal operation

Inventive Principle:
Principle #15Dynamics

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

Enhances driving range, reduces charging time, and addresses range anxiety by providing flexible energy management, especially during towing and high-demand scenarios, while improving compatibility with various charging stations.

Implementation Method 1

The battery pack is the energy storage system of an EV, providing the necessary electrical energy to the motor. Modern EV battery packs are predominantly composed of lithium-ion cells

Methodology Applied
Scientific EffectBattery (electricity): Battery (electricity)

Implementation Method 2

An inverter converts the DC power from the battery pack to AC power to drive the electric motor

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 3

a converter, specifically a DC/DC converter, steps down the high-voltage DC from the battery to a lower voltage to power the vehicle's auxiliary systems

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Data Source

PatentEP4707032A1Electric vehicle range extender integration
Publication Date: 2026.03.11 TESLA INC
  • EP4707032A1 patent drawingFigure 1
  • EP4707032A1 patent drawingFigure 2
  • EP4707032A1 patent drawingFigure 2

AI summary

Example methods to manage a plurality of battery packs of an electric vehicle include initiating a charging process for a primary battery pack and an auxiliary battery pack, determining that an Open Circuit Voltage (OCV) of the primary battery pack matches an OCV of the auxiliary battery pack, and based on determining that the OCV of the primary battery pack matches the OCV of the auxiliary battery, connecting the primary and auxiliary battery packs in parallel and initiating parallel charging of the primary battery pack and the auxiliary battery pack.