Final Report Summary - EASYBAT (Models and generic interfaces for easy and safe Battery insertion and removal in electric vehicles)
Executive Summary:
The overall goal of the EASYBAT project was to develop integration models, mechanisms and generic interfaces for smooth battery pack integration in electric vehicles. These integration models, enabling quick switching of the batteries, were structured around parameters such as safety, weight, battery geometry and location in the vehicle. Cost and environmental aspects were also taken into consideration. The proposed EASYBAT battery integration solution addresses the above limitations and challenges thanks to innovations that outperformed state-of the art EV Battery Switch Stations (BSS), as well as state-of-the-art interoperability between the battery system modules and the vehicle on board-systems.
EASYBAT did not develop new battery interface technologies. However, the integration of the different components, models, and the definition of generic interfaces enabled an innovative approach, resulting in an efficient method to make best use of the switchable batteries in EVs.
The objectives of the first year of the EASYBAT project were to define the system requirements and use-cases, to analyze the implications of the EASYBAT concept including the environmental impact, initiate the system design and architecture of the EASYBAT solution, to develop battery safety guidelines and to set up design rules for an improved battery cycle management.
The concrete achievements of the EASYBAT project for the first year of its activities were:
System requirements and use-cases - Analyzing the existing solutions, defining the requirements from the side of the battery, the car and the battery switch station, defining the requirements with regards to the data sets and definition of the Usage scenarios and car class description
Analysis of the implications of the EASYBAT concept - The EASYBAT team has identified two existing concepts that can be used as basis for a third, new concept, taking the "best practice" of each existing concept, performed system risk analysis – both from the vehicle and the BSS points of view, defined general solution architecture. Gap analysis was initiated between areas that are already standardized, listing the standards to be met, and the areas not yet standardized, where proposals for standards can be given. Listing of legal requirements was initiated and directives and regulations that need to be met for Europe
Battery safety guidelines development - Catalogue of principle battery interface solution and resulting with the EASYBAT safety Tool (Deliverable 5.1) including standards relating to safety of vehicle, battery and BSS
Set up design rules for an improved battery operation cycle management (BOCM) - The initial structure of the BOCM has been set up, identifying the basic functions of BSS and BOCM and their correlation; in this structure, the communication paths between BSS, vehicle and BOCM have been defined.
Environmental impact report – presenting the differences between the electric vechicle (EV) and the internal combustion engine (ICE) vehicle in terms of air emissions and analyzing and quantifying the differences between switchable battery EVs with fix battery EVs. The quantification of the environmental benefit was calculated according to the ExternE Methodology. The Environmental impact was assessed for 3 countries: Denmark, France and Israel – selected for their different scenarios of energy mix and different ratio of EV to ICE vehicles
The EASYBAT consortium achieved the following objectives and results during the second period of the project:
In WP2, the simulation environment has been fully developed and is operational, including sub-models for range coverage and electrical drive energy. Also, the power plant and transmission simulation tool and electric vehicle load generation and grid connectivity tool are programmed and operational.
In WP3, the final system architecture and detailed design have been developed. The mechanical interface high level drawing and electrical and cooling interface concept have been finalized.
In WP4, the generic mechanical interface design was agreed upon and developed. Modifications to the existing electrical interface design were defined and a new concept for a liquid cooling interface was developed.
In WP5 essential design rules have been defined and established a model for weight analysis and simulations for different battery packaging scenarios.
In WP6, the communication architecture, communication flow in different stages or state of operation, timing and content of data transmitted was developed. The structure of the BOCM has been set up and demonstrated, and the battery aging tests were finalized.
In WP8 – Dissemination, Standardization and Exploitation of Results – the EASYBAT consortium has made continuous presentations at conferences and fairs, as well as several scientific publications.
Finally, a Standardization Workshop Agreement was developed at the end of the project under the auspices of CEN/CENELEC The Workshop’s goal was to suggest new battery pack generic interfaces and to reach consensus on such standards in an open format that will be published as one or more CENELEC Workshop Agreements.
Project Context and Objectives:
Scientific/Technological Objectives
The overall goal of the EASYBAT project was to develop integration models, mechanisms and generic interfaces for smooth battery pack integration in electric vehicles. This integration models enabling quick switch of the batteries, are structured around parameters such as safety, weight, battery geometry and location in the vehicle. It also takes into consideration cost and environmental aspects. The proposed EASYBAT battery pack integration solution addresses the above limitations and challenges thanks to innovations that outperformed state-of the art EVBs, as well as state-of-the-art interoperability between the battery system modules and the vehicle on board-systems.
EASYBAT did not develop new battery technologies. However, the integration of the different components, models, and the definition of generic interfaces enables an innovative approach, resulting in an efficient method to make best use of the latest battery innovations. Finally, to evaluate the effectiveness and added value of its approach, the EASYBAT project thoroughly and continuously compared its performance to the current generation systems and technologies such as the ones used in plug-in hybrids vehicles.
The ecosystem includes the vehicle on-board systems, the battery pack (including the battery management mechanisms), the interfaces and communication bus between the battery pack and the vehicle, and a remote control center. Although EASYBAT's scope does not include the integration with a battery exchange station, the model and interfaces it proposes takes into consideration this aspect. Based on EASYBAT's outcomes, further research was focused on the interface between the battery and the infrastructure. This ensured proper battery exchange process as well as battery charging (the Smart Charging Management in the battery exchange station would ensure the charging of multiple and potentially different batteries given different optimization parameters).
Research objectives
The envisaged research performed in EASYBAT consisted of 3 main parts:
1. Building models and mechanisms for an easy and safe integration of battery packs in electric vehicles – This objective defined a generic model for battery pack insertion, release, and load within the EV expandable battery bay.
2. Developing generic interfaces to enable interoperability and interchangeability between the battery and the vehicle on board-systems – This objective aimed at providing fixed and next generation switchable batteries with generic interfaces to the host vehicle.
3. Assessment of EASYBAT's solution in terms of cost, logistics, and environmental impact - Evaluation of EASYBAT's switching next generation concept efficiency compared to plug-in hybrid vehicles batteries systems – In this objective, the analyzed impacts was benchmarked with concepts alternative to pure electric vehicles as plug-in hybrid vehicles.
Objective 1: Building models and mechanisms for an easy and safe integration of battery packs in electric vehicles
Batteries are complex, heavy, large and expensive components with limited lifespan. Today EV vendors are using many types of batteries which differ from each other in terms of size and geometry, chemistry, internal module structure (cells), capacity, location in the vehicle etc. This objective addressed these issues especially in existing solutions in order to define a generic model for battery pack integration which enabled the battery pack to be easily integrated into the chassis of EVs (in the battery bay). In parallel, technological solutions to perform a generic release and load mechanism was explored. EASYBAT battery pack model was also developed in consideration of cost efficiency and its impact on the environment.
The following areas were included in the research to achieve this first objective:
• Improving battery pack geometry and type providing maximal capacity at minimal volume
• Identification of the optimal location of battery in the vehicle – rear, front. Safety requirements will be defined as the location of the battery affects the vehicle stability, drive behaviour and crash behaviour
• Comprehensive risk assessment for electric safety at the level of the developed components in case of misuse or fire for the multi storage and charging facility
• Assessment of risk in storing multiple Li-ion batteries. Definition of safety regulations and certification process for storage facilities (Health and environmental risks will be taken into account)
• Research on release mechanism such as the internal vehicle release mechanism.
• Definition of the safety precautions that needs to be implemented as mandatory steps in the release process in addition to the general safety requirements of the battery.
• Environmental parameters: Battery exchange has to function in very different environments and adverse conditions, such as extremely hot or cold climate, snow or sand drift, wet climate with strong rain. Battery exchange has to be accommodated that there is no spillage of fluids or residues (such as when disconnecting coolant lines). Use of materials that are harmful to the environment has to be minimized or avoided.
Objective 2: Developing generic interfaces to enable interoperability, interchangeability and communication between the battery system modules and the vehicle on board-systems
This objective aimed at defining and developing generic interfaces for fixed and switchable batteries with the vehicle hosting them. This objective addressed and defined the mandatory interfaces that are involved during battery operation and that need to be standardized in order to support efficient EV operation across Europe. The main interfaces between the battery pack and the vehicle are the (1) cooling, (2) data exchange (3) electrical and (4) mechanical (to release and secure the battery). When inserted in the vehicle, the switchable battery pack had to communicate via the CAN bus to the vehicle components through the interfaces including connectors. A wireless communication interface in the car transmitted battery pack related data to a remote control center. The control center supervised the battery life cycle management, collected statistical usage data, and initiated and control safety and operation related parameters.
The generic interfaces was researched in view to contribute to current and future standard initiatives and to promote the creation of new standards in the area of Switchable Battery EV’s interconnection.
The research areas for this objective included:
• Automotive grade battery electricity interface (High power electrical interface permits flow of energy from battery to electric motor, and from in-vehicle electric charger to battery)
• Automotive grade battery data interface (Low power electrical interface permits exchange of data between battery and vehicle)
• Automotive grade battery cooling interface (Battery needs controlled cooling that can be air or liquid. Cooling generator is in vehicle. Coolant (air or liquid) needs to be circulated in the battery)
• Automotive grade safe mechanical interface that permits insertion and release of a battery pack in the vehicle by a battery exchange station. Mechanical release mechanism including ways to trigger a battery release mechanism
• Requirements for a Connect / Disconnect battery to vehicle, for a Connect / Disconnect battery to vehicle cooling system and , for a Connect / Disconnect battery to vehicle data connector.
Objective 3: Assessment of EASYBAT's solution in terms of cost, logistics, and environmental impact - Evaluation of EASYBAT's switching concept efficiency in comparison with alternative vehicles batteries systems
This objective researched the implications of deploying the EASYBAT switching solution at different scales. The implications were determined by evaluating the EASYBAT impact at different levels: environmental, cost, logistics and battery life cycle. The cost and logistics impact will be measured for the different major actors: OEM’s, Battery manufacturers, charging stations and car buyers. The analyzed impact will be then benchmarked with concepts alternative to pure electric vehicles as plug-in hybrid vehicles.
The research areas for this objective will include:
• Environmental impacts of different range extension solutions (such as hybrid, on board range extension engine, battery swap).
• Impacts of battery swap stations on the amount of renewable energy used throughout the day
• Financial quantification (euro/annum) of the environmental benefit (air externalities)
• A comparison between the EASYBAT battery swap solution and conventional EVs at fast charge stations
• Evaluate and measures the implications of a deployment of switchable batteries at a large scale and provides a model for a cost efficiency deployment
• Logistics and battery life cycle: evaluate the logistics implication for the switching stations, for the cars owners.
• Benchmark of the system performance with alternative concepts (such as hybrid, on board range extension engine) continuously during the project
Project Results:
Interfaces requirements
“The Battery is the Car”. New traction battery packs make the fully electric vehicles more and more capable. Their share of the price of the car is set to become even more dominant. Factors driving this include the strident demand for better car range. Battery packs increasingly incorporate electronics for safety and power conversion. The integration of these new complex battery packs presents major challenges especially considering the current lack of standards.
EASYBAT’s main mission was to address these integration challenges by defining new concepts for the smart insertion of batteries and by developing in particular generic interfaces for electric vehicles. This research aims at enabling smooth batteries integration and swap.
The EASYBAT integration system was developed for fully electric vehicles.
The EASYBAT consortium includes a major electric vehicle services provider, one of the top global OEMs, a leading automotive supplier, research institutes covering fields of expertise such as safety & security, interfaces and communication protocols, EVs electrical architecture, and standardization within the IEC/ISO.
Together, the EASYBAT partners offered solutions enabling cost effective, environmental friendly switchable battery packs and will contribute unleashing the EVs potential for a wider use.
The 3 main objectives were achieved: identify existing exchangeable battery interfaces solutions (1st generation) available on the market, analyze the overall improvements and modifications required to be done on the existing interfaces solutions, for both the vehicle and the battery necessary to develop a generic interfaces solution and define use-cases for the next generation interfaces solution and field test.
The analysis of existing solutions and the constraints we identified regarding size, weight, height, tolerance and alignment lead us to conclude that the next generation battery type must be a "flat"/"pancake" battery located in the under floor of the vehicle, between the wheel axels.
System Integration
The architecture identifies the external and internal interactions points of a switchable battery, and fulfills the functional and the non-functional requirements defined in WP1 to provide a safe, reliable, extensible, cost effective and open platform for handling all interactions between the EV battery pack and the vehicle.
The analysis of the final architecture and the requirements defined in deliverable D1.2 specifically of the mechanical mechanism, reveal the requirements for tolerance and alignment are very difficult to implement (from technological, time and cost points of view), making a mass market implementation of the current solution very expensive.
Therefore, one of the leading motivations for coming up with a new architecture concept, was to simplify and improve the alignment process by replacing the mechanical mechanism.
The location, dimension and actuation of the mechanical mechanism served as reference to the position of all other connectors (electrical, data and thermal).
The extended requirement to define a generic solution suitable for all vehicles, from the small 2-seat A class through to the D class and the need to take into consideration the constraints on the switching station results in a generic architecture concept whose implementation is divided into 2 solutions. One solution met the requirements for the small A class vehicles, the second solution met the requirements for the larger B, C and D classes.
Each of the interface connectors were designed individually according to its own requirements, without considering its location.
This gave each OEM the freedom to define his own battery with regards to battery dimension, design and connector location as long as the connector itself meets the standard.
The BSS was able to switch such a battery with only the information of the location and orientation of the mechanism, and charge it with the information of the location and orientation of all interfaces.
Battery Interface
Key recommendations were set out from various options and technologies analyzed as part of the EASYBAT project with regards to achieving generic interfaces for mechanical, cooling, and data & electrical systems between the Electric Vehicle (EV), Battery and Battery Switch Station (BSS).
Evaluation as to whether these interface recommendations can be applied in a generic way to other EV's and Hybrid EV's (HEV's) will be explored, and for each interface type, we will attempt to specify if it can be used 'as is' or whether some modifications are required.
A summary of each interface system developed in WP4 of the EASYBAT project is provided below:
Mechanical Interface:
The generic mechanical battery interface covers:
- Functional needs
- Battery unlocking / locking process during switch operation
- A detailed description of the mechanism (including: dimensions and weight)
- Prototype development and manufacturing
The functions have been determined to fulfill the needs of
- General architecture defined in WP3.
- BSS process simplification in respect to the functional and external requirements defined in WP1.
The resulting recommendation is a mechanism which has been prototyped; is to be tested and integrated in the vehicle prototype, in the framework of WP7.
Data and Electrical Interface:
The analysis conducted revealed that the data interface from the Renault Fluence should be adopted. This could evolve according to future generic needs which may be identified at a later date.
It was determined that the electrical interface should also be based on the Renault Fluence and ZOE models, and achieves all functions and technical requirements defined in WP1. It must also be compatible with:
- The general system requirement defined in WP1, for example: vertical battery switching.
- All battery lay out scenarios as defined in WP3.
The interoperability requirements lead us to propose that this interface be standardized for all battery types, vehicles and BSS chargers. Improvements have been proposed where necessary.
Cooling Interface:
The cooling interface differs from the other interfaces previously mentioned in that a final solution has not yet been identified, and as such the work revolves around analyzing the feasibility of different solutions and refinement of the preferred technology.
The objectives for this WP are to:
- Analyze different cooling interface solutions available (e.g. air and liquid) building upon experience gained from the current Renault ZOE model (air cooling).
- Perform tests to identify the most suitable liquid cooling interface solution, and to validate it from the perspective of cost and technical feasibility.
The liquid cooling interface provides benefits for example in reducing the battery packaging height, necessary for designing a low height EV sedan.
Testing requirements for a Liquid Battery cooling interface system took into account:
- The risk associated with leakage
- The influence of misalignment on the functionality of the interface mechanism on the x, y and angular axes.
The following test conditions were performed:
- Simulating mass flow and pressure similar to those that will exist in reality during coupling and decoupling.
- Simulating misalignment during coupling and decoupling on X, Y and angular axes.
- Simulating a life-cycle of battery switching, based on a 3000 cycle test of coupling and decoupling.
The recommendation based on the technical results is that a liquid cooling system is the preferred option. RN disagreement: it is too early to conclude. EASYBAT should propose both solutions
Optimization tool for vehicle integration of battery
A decision support tool for optimizing the position of battery assemblies in a passenger car was developed. In an analysis of the decision process it was shown that the battery positions are very crucial in the very early design phase of an e-car. Of course switchable batteries have an additional design and configuration-space when it comes to the decision where they should be placed. In general the configuration and decision space encompasses many parameters from passenger comfort and safety to dynamic behaviour of the car. A total optimization in the configuration space is therefore almost impossible, it can be expected that different parameters are in conflict when trying to search for a global optimum.
In the current state, the decision support tool is focused on the evaluation of dynamic effects for e-cars caused by the mass of the batteries. Following the finding, that the mass of the batteries is around one third of the entire car and the possibilities to distribute the weight to a large portion is very limited, the work started with an analysis of the drive effects of the battery position in a simulation system. It could be shown that even the relocation of the static centre of gravity by the position of the heavy batteries can cause severe stability problems for the car dynamics. Associated with this is a safety problem for the car which could turn out to be not manageable by the electronic stability control.
To avoid expensive and dangerous design failures in e-car development, the designer should have an instrument to quickly evaluate the battery positions alternatively at least under the aspect of the dynamic effects. Since this tool becomes effective from the very first design sketches to final integration of the entire car the developed system is the basis for flexible extension following the life cycle of an e-car. Therefore it starts with minimized data requirements on the car. Only the few parameters available in the first design phase are needed for a first evaluation of battery positions giving an immediate numerical estimation of the quality of the chosen battery position and expected problems related to the decision. Basis of this decision support system is the calculation of the relocation of the centre of gravity by the position and mass of batteries. The distance from an optimum gives an indication for the quality of the position decision.
This optimization tool was implemented and tested with basic data of an existing car in a driving simulation which gives the dynamic forces on the car in typical driving situations. It was shown that the method chosen for the architecture of the optimization tool is adequate and the system usable in e-car design. Furthermore the simulation system and the tests with real car data enabled to set global decision borders as parameters for the optimization tool. With these parameters, the car designer will be provided with an immediate GOOD/BAD evaluation of the chosen battery positions.
Battery Operation Cycle Management system
The EASYBAT project investigates the concept of easy and safe battery switching for electric vehicles with switchable batteries. The switching of the EV battery offers opportunities for an optimal treatment of the battery outside of the vehicle. For this optimal treatment, a system has been developed in the EASYBAT project to keep track of all switchable batteries within the fleet of an electro-mobility service provider. This system is called the Battery Operation Cycle Management system (BOCM) and is described in this Deliverable, D6.4. The BOCM receives relevant data of all switchable batteries and processes this and stores it in the BOCM database. This database contains the historic information of all batteries including the vehicles they have been used in. From this information, the age of each battery is tracked and calculated. The performance indicator used for the battery age is the state of health (SOH). The SOH is calculated by the BOCM using the battery degradation model developed in the EASYBAT project.
The main function of the BOCM is to assign a certain battery to an electric vehicle waiting at the battery switch station (BSS), with the aim to optimise the overall age of all batteries in the fleet. This BOCM algorithm uses the SOH information of all batteries inside the BSS and information about the vehicle to make this selection. This algorithm is explained in this document.
This document also describes the implementation of the BOCM system: the data exchange needed, the communication protocol using the web service concept, the BOCM database structure to store and handle the battery data. Because the BOCM is developed as a web service in the internet cloud, no specific hardware is needed.
To demonstrate the functionality of the BOCM, a test setup has been used for testing. In this test, one PC is used as the BOCM server and one PC as the client accessing the server. The test, described in this document, proves that the BOCM web service is successfully implemented and functioning correctly.
System Validation
EASYBAT system interfaces concept is validated with the following reserves:
- Material of some mechanism parts to clarify or to adapt to anticorrosion constraints
- Mechanisms reliability and durability since the component tests could not be achieved by Better Place
- Mechanism weight to be improved (material and geometry)
- Mechanism bell crank to be designed with a hexagonal hole
- Mechanism lay out in the vehicle : battery switching with the proposed antagonist lay out as a solution remains to be validated
- Additional XY reference on the mechanism housing in order to improve battery positioning on the vehicle before locking
- Resistance to the external environment (water, mud, dust, grave, frost)
Given the multiple benefits it brings (switching time performance, BSS cost reduction, process tool standardization), the EASYBAT team considers this solution viable and able to be the future standard, not only European but also worldwide, and could be a reference for its future switchable battery projects.
Standardization
The CEN-Cenelec workshop agreement (CWA) report has been drafted as a collaboration of contributing partners under the EASYBAT consortium and additional stakeholders. This CWA mainly describes the battery swap process, the EASYBAT system architecture and interfaces (mechanical, electrical, cooling and data interfaces), excluding all safety items as requested by some countries during the international consultation. This CWA is essential to prepare standardization which is inescapable for EV, battery and BSS interoperability. It may lead in the future, to a standard to be developed when the need will be confirmed by the development of new systems by car manufacturers and battery swap service providers.
Potential Impact:
Strategic impact
The strategic objective "GC.SST.2010.7-4: Smart storage integration" lists the impact of the battery smart storage integration at four different levels: environmental, cost, logistic and life cycle. As described in the different following sections (technological, socio-economic and environmental), the EASYBAT project addressed each of these levels of impact.
Technological Impact
''Advanced battery technology is one of the most important technical issues being addressed by Alliance members today''. — Robert Strassburger, Vice President of Safety and Harmonization of the Alliance of Automobile Manufacturers.
The EASYBAT project established models and generic interfaces for the safe, fast and automated exchange of battery systems. For all interface types concerned, cooling medium, electrical high voltage and mechanical fixation, we derived the existing technologies towards automotive qualified solutions that outperformed existing technologies and standards.
EASYBAT's technological impact is significant in a number of fields:
Communication interface between an electric vehicle and its battery:
Today, batteries are connected and disconnected manually, which greatly impedes their wider diffusion as it implies a delicate and long process. EASYBAT developed generic plug-and-socket connectors with safety locking mechanism that can be connected and disconnected in an automated way without any manual interaction
Connectors
In today's EVs and HEVs the batteries are fixed by screws once in a lifetime, which prevents them from withstanding a high number of connect / disconnect cycles in an engine compartment environment. EASYBAT developed an automated, automotive proof hose connect / disconnect mechanism that can operate several thousands of cycles without manual interaction. EASYBAT provided a standard mechanism applicable to the mass market.
Cooling
The cooling of EV batteries is usually done by liquid cooling media. EASYBAT developed the usage of a common gaseous cooling media for vehicle and batter.
These elements, as well as the safety guidelines for battery, battery packaging, swapping mechanism and the design rules for battery, and EVs' interfaces, developed in EASYBAT form the technological base for the European wide implementation of EVs as general purpose cars. The highest technological impact is on European car manufacturers and swapping mechanism providers. The main benefits are as follow: The technological benefits EASYBAT can bring to OEMs are the product safety, a standardization that will leave a maximum flexibility in vehicle design, and the possibility to increase the drive dynamic performance. The benefit EASYBAT brings to swapping mechanism providers are the product safety, a base for the design of swapping kinematic, and a standard for electrical and mechanical interface on swapping kinematic side.
Socio-economic and environmental benefits of the project
"The battery is the cleverest and most expensive part of electric vehicles ." It is also the technical element that will constrain the range an electric vehicle can cover. Yet, price and range are precisely the two foremost issues hindering the wider adoption of electric vehicles by automakers and end-users.
Economic benefits
In terms of EVs cost
EASYBAT offered models and generic interfaces for a battery integration system that drive the path to standardization, making the battery swap cost effective. EASYBAT's definition of standardized interfaces between the vehicle and the battery allows to mass producing electric vehicles batteries, reducing the global cost of EVs, and turning them into a realistic and affordable solution. Moreover, the battery integration system standardization gives to Europe a comparative advantage over Japan and the U.S where standards are still to be defined.
Moreover, thanks to generic interfaces and to the battery management system (BMS), batteries are used in an optimized way, which enables battery economies, which in turn trigger a lower consumption of batteries, and some energy savings.
In terms of EVs range extension
Another major advantage EASYBAT provides is a solution to the "range anxiety", which currently hinders the EVs market growth. "Range anxiety" refers to the fear of being stranded by an electric car because of insufficient battery performance or charge; it is related to the limited range EVs can offer.
EASYBAT's goal was to create interfaces for batteries which can be completely re-charged via three processes: a standard charge (which takes between four and eight hours), a battery swap (which takes less than five minutes), or a quick charge (which recharges the battery to 80% state of charge in 20 minutes). Contributing to defining interfaces for an easy battery integration and removal, EASYBAT helps avoiding the "range anxiety" among car users, and unleash the EVs market development
Social and environmental benefits
EASYBAT offers a maximal environment protection: zero emission
The necessity to explore electric cars other than the conventional combustion engine is driven by the cost these vehicles entail in terms of petrol consumption – this is true especially during peaks such as the one that happened during the summer 2008, when the price of oil spiked to more than 150 US$ per barrel. However, while the oil prices can fall, as they have done since 2008, climate change concerns compel manufacturers to continue searching for technologies that would not trigger any damage the environment. This was made clear by governments during the United Nations Climate Change conference that recently took place in Copenhagen.
Today, plug-in hybrid vehicles provide a solution to reduce CO emissions. Preliminary studies recently performed showed that replacing ICE vehicles by plug-in hybrids would trigger a CO2 reduction included in a range of 28 to 67 million Euro per year in the various scenarios and at a CO2 price of 14.8 Euro per ton, or 42 to 139 million Euro per year in the various scenarios at a CO2 price of 50 Euro per ton.
Taking those results a step further, replacing ICE’s with vehicles with a swappable battery (EASYBAT's preferred application) together with switching stations that use renewable energy can secure an environmental benefit of 113 million Euros per year at a CO2 price of 14.8 Euro per ton or 270 Euro per year at a CO2 price of 50 Euro per ton.
EASYBAT's vision on the long term entails the use of renewable energy to exchange a battery at a switching station. This enables EVs to accelerate the transformation of charging stations into sustainable power generation slots. A study of the renewable energy power demand necessary to charge EVs was performed by the Institute for Energy Economy and Application Technology (IfE), at the Technical University of Munich. This study concluded that the charging of batteries at battery swap stations enables to leverage more renewable energy in the provided charging power mix than in any other way of charging EVs. Therefore, EASYBAT's vision on the long term is highly beneficial to the environment: not only it reduces CO2 emissions by offering a zero emissions alternative to ICEs, but it also triggers the leverage and storage of renewable energy in charging stations.
Added Value at the European level
To remain a leader in the field of green cars, Europe has to offer innovative batteries systems to suit electric cars from technological and commercial perspectives. The EASYBAT project is led by partners representing different European countries, and covering the full range of activities necessary to achieve the integration of a new battery system in electric vehicles. The EASYBAT's project therefore lies on European OEMs and end-users' needs, and is validated in its European environment. The EASYBAT solution's adoption by European OEMs and end-users is also faster since it is offered across Europe, increasing the market acceptance at the European level.
This European feature has many positive outcomes. Firstly, EASYBAT proposes a generic battery integration model which could set a base for a European standardized battery, increasing the batteries' interchangeability and improving their batteries interoperability among European OEMs. Secondly, as EASYBAT offers a generic battery interface which allows the production of generic battery on large scale at an affordable price..
Furthermore, EASYBAT proposes a pan-European solution. The batteries interfaces developed by EASYBAT take account models in which the battery can be completely re-charged via a standard charge or changed in less time than it takes to top off an ICE (internal combustion engine) car with petrol. The range extension potentially provided by such a solution is unlimited. Therefore, it allows European drivers to drive through Europe without any technical restrictions.
EASYBAT has the capacity to contribute to the preparation of standards, homogenized across Europe, while developing synergies between various actors and contributing to new business models that can take advantage of interchangeability and full interoperability. Therefore, EASYBAT helps strengthening Europe's position as a leader in the competitive green cars industry.
Contribution to standards
The CEN-Cenelec workshop agreement (CWA) report has been drafted as a collaboration of contributing partners under the EASYBAT consortium and additional stakeholders. This CWA mainly describes the battery swap process, the EASYBAT system architecture and interfaces (mechanical, electrical, cooling and data interfaces), excluding all safety items as requested by some countries during the international consultation. This CWA is essential to prepare standardization which is inescapable for EV, battery and BSS interoperability. It may lead in the future, to a standard to be developed when the need will be confirmed by the development of new systems by car manufacturers and battery swap service providers.
List of Websites:
http://www.easybat.eu/
The overall goal of the EASYBAT project was to develop integration models, mechanisms and generic interfaces for smooth battery pack integration in electric vehicles. These integration models, enabling quick switching of the batteries, were structured around parameters such as safety, weight, battery geometry and location in the vehicle. Cost and environmental aspects were also taken into consideration. The proposed EASYBAT battery integration solution addresses the above limitations and challenges thanks to innovations that outperformed state-of the art EV Battery Switch Stations (BSS), as well as state-of-the-art interoperability between the battery system modules and the vehicle on board-systems.
EASYBAT did not develop new battery interface technologies. However, the integration of the different components, models, and the definition of generic interfaces enabled an innovative approach, resulting in an efficient method to make best use of the switchable batteries in EVs.
The objectives of the first year of the EASYBAT project were to define the system requirements and use-cases, to analyze the implications of the EASYBAT concept including the environmental impact, initiate the system design and architecture of the EASYBAT solution, to develop battery safety guidelines and to set up design rules for an improved battery cycle management.
The concrete achievements of the EASYBAT project for the first year of its activities were:
System requirements and use-cases - Analyzing the existing solutions, defining the requirements from the side of the battery, the car and the battery switch station, defining the requirements with regards to the data sets and definition of the Usage scenarios and car class description
Analysis of the implications of the EASYBAT concept - The EASYBAT team has identified two existing concepts that can be used as basis for a third, new concept, taking the "best practice" of each existing concept, performed system risk analysis – both from the vehicle and the BSS points of view, defined general solution architecture. Gap analysis was initiated between areas that are already standardized, listing the standards to be met, and the areas not yet standardized, where proposals for standards can be given. Listing of legal requirements was initiated and directives and regulations that need to be met for Europe
Battery safety guidelines development - Catalogue of principle battery interface solution and resulting with the EASYBAT safety Tool (Deliverable 5.1) including standards relating to safety of vehicle, battery and BSS
Set up design rules for an improved battery operation cycle management (BOCM) - The initial structure of the BOCM has been set up, identifying the basic functions of BSS and BOCM and their correlation; in this structure, the communication paths between BSS, vehicle and BOCM have been defined.
Environmental impact report – presenting the differences between the electric vechicle (EV) and the internal combustion engine (ICE) vehicle in terms of air emissions and analyzing and quantifying the differences between switchable battery EVs with fix battery EVs. The quantification of the environmental benefit was calculated according to the ExternE Methodology. The Environmental impact was assessed for 3 countries: Denmark, France and Israel – selected for their different scenarios of energy mix and different ratio of EV to ICE vehicles
The EASYBAT consortium achieved the following objectives and results during the second period of the project:
In WP2, the simulation environment has been fully developed and is operational, including sub-models for range coverage and electrical drive energy. Also, the power plant and transmission simulation tool and electric vehicle load generation and grid connectivity tool are programmed and operational.
In WP3, the final system architecture and detailed design have been developed. The mechanical interface high level drawing and electrical and cooling interface concept have been finalized.
In WP4, the generic mechanical interface design was agreed upon and developed. Modifications to the existing electrical interface design were defined and a new concept for a liquid cooling interface was developed.
In WP5 essential design rules have been defined and established a model for weight analysis and simulations for different battery packaging scenarios.
In WP6, the communication architecture, communication flow in different stages or state of operation, timing and content of data transmitted was developed. The structure of the BOCM has been set up and demonstrated, and the battery aging tests were finalized.
In WP8 – Dissemination, Standardization and Exploitation of Results – the EASYBAT consortium has made continuous presentations at conferences and fairs, as well as several scientific publications.
Finally, a Standardization Workshop Agreement was developed at the end of the project under the auspices of CEN/CENELEC The Workshop’s goal was to suggest new battery pack generic interfaces and to reach consensus on such standards in an open format that will be published as one or more CENELEC Workshop Agreements.
Project Context and Objectives:
Scientific/Technological Objectives
The overall goal of the EASYBAT project was to develop integration models, mechanisms and generic interfaces for smooth battery pack integration in electric vehicles. This integration models enabling quick switch of the batteries, are structured around parameters such as safety, weight, battery geometry and location in the vehicle. It also takes into consideration cost and environmental aspects. The proposed EASYBAT battery pack integration solution addresses the above limitations and challenges thanks to innovations that outperformed state-of the art EVBs, as well as state-of-the-art interoperability between the battery system modules and the vehicle on board-systems.
EASYBAT did not develop new battery technologies. However, the integration of the different components, models, and the definition of generic interfaces enables an innovative approach, resulting in an efficient method to make best use of the latest battery innovations. Finally, to evaluate the effectiveness and added value of its approach, the EASYBAT project thoroughly and continuously compared its performance to the current generation systems and technologies such as the ones used in plug-in hybrids vehicles.
The ecosystem includes the vehicle on-board systems, the battery pack (including the battery management mechanisms), the interfaces and communication bus between the battery pack and the vehicle, and a remote control center. Although EASYBAT's scope does not include the integration with a battery exchange station, the model and interfaces it proposes takes into consideration this aspect. Based on EASYBAT's outcomes, further research was focused on the interface between the battery and the infrastructure. This ensured proper battery exchange process as well as battery charging (the Smart Charging Management in the battery exchange station would ensure the charging of multiple and potentially different batteries given different optimization parameters).
Research objectives
The envisaged research performed in EASYBAT consisted of 3 main parts:
1. Building models and mechanisms for an easy and safe integration of battery packs in electric vehicles – This objective defined a generic model for battery pack insertion, release, and load within the EV expandable battery bay.
2. Developing generic interfaces to enable interoperability and interchangeability between the battery and the vehicle on board-systems – This objective aimed at providing fixed and next generation switchable batteries with generic interfaces to the host vehicle.
3. Assessment of EASYBAT's solution in terms of cost, logistics, and environmental impact - Evaluation of EASYBAT's switching next generation concept efficiency compared to plug-in hybrid vehicles batteries systems – In this objective, the analyzed impacts was benchmarked with concepts alternative to pure electric vehicles as plug-in hybrid vehicles.
Objective 1: Building models and mechanisms for an easy and safe integration of battery packs in electric vehicles
Batteries are complex, heavy, large and expensive components with limited lifespan. Today EV vendors are using many types of batteries which differ from each other in terms of size and geometry, chemistry, internal module structure (cells), capacity, location in the vehicle etc. This objective addressed these issues especially in existing solutions in order to define a generic model for battery pack integration which enabled the battery pack to be easily integrated into the chassis of EVs (in the battery bay). In parallel, technological solutions to perform a generic release and load mechanism was explored. EASYBAT battery pack model was also developed in consideration of cost efficiency and its impact on the environment.
The following areas were included in the research to achieve this first objective:
• Improving battery pack geometry and type providing maximal capacity at minimal volume
• Identification of the optimal location of battery in the vehicle – rear, front. Safety requirements will be defined as the location of the battery affects the vehicle stability, drive behaviour and crash behaviour
• Comprehensive risk assessment for electric safety at the level of the developed components in case of misuse or fire for the multi storage and charging facility
• Assessment of risk in storing multiple Li-ion batteries. Definition of safety regulations and certification process for storage facilities (Health and environmental risks will be taken into account)
• Research on release mechanism such as the internal vehicle release mechanism.
• Definition of the safety precautions that needs to be implemented as mandatory steps in the release process in addition to the general safety requirements of the battery.
• Environmental parameters: Battery exchange has to function in very different environments and adverse conditions, such as extremely hot or cold climate, snow or sand drift, wet climate with strong rain. Battery exchange has to be accommodated that there is no spillage of fluids or residues (such as when disconnecting coolant lines). Use of materials that are harmful to the environment has to be minimized or avoided.
Objective 2: Developing generic interfaces to enable interoperability, interchangeability and communication between the battery system modules and the vehicle on board-systems
This objective aimed at defining and developing generic interfaces for fixed and switchable batteries with the vehicle hosting them. This objective addressed and defined the mandatory interfaces that are involved during battery operation and that need to be standardized in order to support efficient EV operation across Europe. The main interfaces between the battery pack and the vehicle are the (1) cooling, (2) data exchange (3) electrical and (4) mechanical (to release and secure the battery). When inserted in the vehicle, the switchable battery pack had to communicate via the CAN bus to the vehicle components through the interfaces including connectors. A wireless communication interface in the car transmitted battery pack related data to a remote control center. The control center supervised the battery life cycle management, collected statistical usage data, and initiated and control safety and operation related parameters.
The generic interfaces was researched in view to contribute to current and future standard initiatives and to promote the creation of new standards in the area of Switchable Battery EV’s interconnection.
The research areas for this objective included:
• Automotive grade battery electricity interface (High power electrical interface permits flow of energy from battery to electric motor, and from in-vehicle electric charger to battery)
• Automotive grade battery data interface (Low power electrical interface permits exchange of data between battery and vehicle)
• Automotive grade battery cooling interface (Battery needs controlled cooling that can be air or liquid. Cooling generator is in vehicle. Coolant (air or liquid) needs to be circulated in the battery)
• Automotive grade safe mechanical interface that permits insertion and release of a battery pack in the vehicle by a battery exchange station. Mechanical release mechanism including ways to trigger a battery release mechanism
• Requirements for a Connect / Disconnect battery to vehicle, for a Connect / Disconnect battery to vehicle cooling system and , for a Connect / Disconnect battery to vehicle data connector.
Objective 3: Assessment of EASYBAT's solution in terms of cost, logistics, and environmental impact - Evaluation of EASYBAT's switching concept efficiency in comparison with alternative vehicles batteries systems
This objective researched the implications of deploying the EASYBAT switching solution at different scales. The implications were determined by evaluating the EASYBAT impact at different levels: environmental, cost, logistics and battery life cycle. The cost and logistics impact will be measured for the different major actors: OEM’s, Battery manufacturers, charging stations and car buyers. The analyzed impact will be then benchmarked with concepts alternative to pure electric vehicles as plug-in hybrid vehicles.
The research areas for this objective will include:
• Environmental impacts of different range extension solutions (such as hybrid, on board range extension engine, battery swap).
• Impacts of battery swap stations on the amount of renewable energy used throughout the day
• Financial quantification (euro/annum) of the environmental benefit (air externalities)
• A comparison between the EASYBAT battery swap solution and conventional EVs at fast charge stations
• Evaluate and measures the implications of a deployment of switchable batteries at a large scale and provides a model for a cost efficiency deployment
• Logistics and battery life cycle: evaluate the logistics implication for the switching stations, for the cars owners.
• Benchmark of the system performance with alternative concepts (such as hybrid, on board range extension engine) continuously during the project
Project Results:
Interfaces requirements
“The Battery is the Car”. New traction battery packs make the fully electric vehicles more and more capable. Their share of the price of the car is set to become even more dominant. Factors driving this include the strident demand for better car range. Battery packs increasingly incorporate electronics for safety and power conversion. The integration of these new complex battery packs presents major challenges especially considering the current lack of standards.
EASYBAT’s main mission was to address these integration challenges by defining new concepts for the smart insertion of batteries and by developing in particular generic interfaces for electric vehicles. This research aims at enabling smooth batteries integration and swap.
The EASYBAT integration system was developed for fully electric vehicles.
The EASYBAT consortium includes a major electric vehicle services provider, one of the top global OEMs, a leading automotive supplier, research institutes covering fields of expertise such as safety & security, interfaces and communication protocols, EVs electrical architecture, and standardization within the IEC/ISO.
Together, the EASYBAT partners offered solutions enabling cost effective, environmental friendly switchable battery packs and will contribute unleashing the EVs potential for a wider use.
The 3 main objectives were achieved: identify existing exchangeable battery interfaces solutions (1st generation) available on the market, analyze the overall improvements and modifications required to be done on the existing interfaces solutions, for both the vehicle and the battery necessary to develop a generic interfaces solution and define use-cases for the next generation interfaces solution and field test.
The analysis of existing solutions and the constraints we identified regarding size, weight, height, tolerance and alignment lead us to conclude that the next generation battery type must be a "flat"/"pancake" battery located in the under floor of the vehicle, between the wheel axels.
System Integration
The architecture identifies the external and internal interactions points of a switchable battery, and fulfills the functional and the non-functional requirements defined in WP1 to provide a safe, reliable, extensible, cost effective and open platform for handling all interactions between the EV battery pack and the vehicle.
The analysis of the final architecture and the requirements defined in deliverable D1.2 specifically of the mechanical mechanism, reveal the requirements for tolerance and alignment are very difficult to implement (from technological, time and cost points of view), making a mass market implementation of the current solution very expensive.
Therefore, one of the leading motivations for coming up with a new architecture concept, was to simplify and improve the alignment process by replacing the mechanical mechanism.
The location, dimension and actuation of the mechanical mechanism served as reference to the position of all other connectors (electrical, data and thermal).
The extended requirement to define a generic solution suitable for all vehicles, from the small 2-seat A class through to the D class and the need to take into consideration the constraints on the switching station results in a generic architecture concept whose implementation is divided into 2 solutions. One solution met the requirements for the small A class vehicles, the second solution met the requirements for the larger B, C and D classes.
Each of the interface connectors were designed individually according to its own requirements, without considering its location.
This gave each OEM the freedom to define his own battery with regards to battery dimension, design and connector location as long as the connector itself meets the standard.
The BSS was able to switch such a battery with only the information of the location and orientation of the mechanism, and charge it with the information of the location and orientation of all interfaces.
Battery Interface
Key recommendations were set out from various options and technologies analyzed as part of the EASYBAT project with regards to achieving generic interfaces for mechanical, cooling, and data & electrical systems between the Electric Vehicle (EV), Battery and Battery Switch Station (BSS).
Evaluation as to whether these interface recommendations can be applied in a generic way to other EV's and Hybrid EV's (HEV's) will be explored, and for each interface type, we will attempt to specify if it can be used 'as is' or whether some modifications are required.
A summary of each interface system developed in WP4 of the EASYBAT project is provided below:
Mechanical Interface:
The generic mechanical battery interface covers:
- Functional needs
- Battery unlocking / locking process during switch operation
- A detailed description of the mechanism (including: dimensions and weight)
- Prototype development and manufacturing
The functions have been determined to fulfill the needs of
- General architecture defined in WP3.
- BSS process simplification in respect to the functional and external requirements defined in WP1.
The resulting recommendation is a mechanism which has been prototyped; is to be tested and integrated in the vehicle prototype, in the framework of WP7.
Data and Electrical Interface:
The analysis conducted revealed that the data interface from the Renault Fluence should be adopted. This could evolve according to future generic needs which may be identified at a later date.
It was determined that the electrical interface should also be based on the Renault Fluence and ZOE models, and achieves all functions and technical requirements defined in WP1. It must also be compatible with:
- The general system requirement defined in WP1, for example: vertical battery switching.
- All battery lay out scenarios as defined in WP3.
The interoperability requirements lead us to propose that this interface be standardized for all battery types, vehicles and BSS chargers. Improvements have been proposed where necessary.
Cooling Interface:
The cooling interface differs from the other interfaces previously mentioned in that a final solution has not yet been identified, and as such the work revolves around analyzing the feasibility of different solutions and refinement of the preferred technology.
The objectives for this WP are to:
- Analyze different cooling interface solutions available (e.g. air and liquid) building upon experience gained from the current Renault ZOE model (air cooling).
- Perform tests to identify the most suitable liquid cooling interface solution, and to validate it from the perspective of cost and technical feasibility.
The liquid cooling interface provides benefits for example in reducing the battery packaging height, necessary for designing a low height EV sedan.
Testing requirements for a Liquid Battery cooling interface system took into account:
- The risk associated with leakage
- The influence of misalignment on the functionality of the interface mechanism on the x, y and angular axes.
The following test conditions were performed:
- Simulating mass flow and pressure similar to those that will exist in reality during coupling and decoupling.
- Simulating misalignment during coupling and decoupling on X, Y and angular axes.
- Simulating a life-cycle of battery switching, based on a 3000 cycle test of coupling and decoupling.
The recommendation based on the technical results is that a liquid cooling system is the preferred option. RN disagreement: it is too early to conclude. EASYBAT should propose both solutions
Optimization tool for vehicle integration of battery
A decision support tool for optimizing the position of battery assemblies in a passenger car was developed. In an analysis of the decision process it was shown that the battery positions are very crucial in the very early design phase of an e-car. Of course switchable batteries have an additional design and configuration-space when it comes to the decision where they should be placed. In general the configuration and decision space encompasses many parameters from passenger comfort and safety to dynamic behaviour of the car. A total optimization in the configuration space is therefore almost impossible, it can be expected that different parameters are in conflict when trying to search for a global optimum.
In the current state, the decision support tool is focused on the evaluation of dynamic effects for e-cars caused by the mass of the batteries. Following the finding, that the mass of the batteries is around one third of the entire car and the possibilities to distribute the weight to a large portion is very limited, the work started with an analysis of the drive effects of the battery position in a simulation system. It could be shown that even the relocation of the static centre of gravity by the position of the heavy batteries can cause severe stability problems for the car dynamics. Associated with this is a safety problem for the car which could turn out to be not manageable by the electronic stability control.
To avoid expensive and dangerous design failures in e-car development, the designer should have an instrument to quickly evaluate the battery positions alternatively at least under the aspect of the dynamic effects. Since this tool becomes effective from the very first design sketches to final integration of the entire car the developed system is the basis for flexible extension following the life cycle of an e-car. Therefore it starts with minimized data requirements on the car. Only the few parameters available in the first design phase are needed for a first evaluation of battery positions giving an immediate numerical estimation of the quality of the chosen battery position and expected problems related to the decision. Basis of this decision support system is the calculation of the relocation of the centre of gravity by the position and mass of batteries. The distance from an optimum gives an indication for the quality of the position decision.
This optimization tool was implemented and tested with basic data of an existing car in a driving simulation which gives the dynamic forces on the car in typical driving situations. It was shown that the method chosen for the architecture of the optimization tool is adequate and the system usable in e-car design. Furthermore the simulation system and the tests with real car data enabled to set global decision borders as parameters for the optimization tool. With these parameters, the car designer will be provided with an immediate GOOD/BAD evaluation of the chosen battery positions.
Battery Operation Cycle Management system
The EASYBAT project investigates the concept of easy and safe battery switching for electric vehicles with switchable batteries. The switching of the EV battery offers opportunities for an optimal treatment of the battery outside of the vehicle. For this optimal treatment, a system has been developed in the EASYBAT project to keep track of all switchable batteries within the fleet of an electro-mobility service provider. This system is called the Battery Operation Cycle Management system (BOCM) and is described in this Deliverable, D6.4. The BOCM receives relevant data of all switchable batteries and processes this and stores it in the BOCM database. This database contains the historic information of all batteries including the vehicles they have been used in. From this information, the age of each battery is tracked and calculated. The performance indicator used for the battery age is the state of health (SOH). The SOH is calculated by the BOCM using the battery degradation model developed in the EASYBAT project.
The main function of the BOCM is to assign a certain battery to an electric vehicle waiting at the battery switch station (BSS), with the aim to optimise the overall age of all batteries in the fleet. This BOCM algorithm uses the SOH information of all batteries inside the BSS and information about the vehicle to make this selection. This algorithm is explained in this document.
This document also describes the implementation of the BOCM system: the data exchange needed, the communication protocol using the web service concept, the BOCM database structure to store and handle the battery data. Because the BOCM is developed as a web service in the internet cloud, no specific hardware is needed.
To demonstrate the functionality of the BOCM, a test setup has been used for testing. In this test, one PC is used as the BOCM server and one PC as the client accessing the server. The test, described in this document, proves that the BOCM web service is successfully implemented and functioning correctly.
System Validation
EASYBAT system interfaces concept is validated with the following reserves:
- Material of some mechanism parts to clarify or to adapt to anticorrosion constraints
- Mechanisms reliability and durability since the component tests could not be achieved by Better Place
- Mechanism weight to be improved (material and geometry)
- Mechanism bell crank to be designed with a hexagonal hole
- Mechanism lay out in the vehicle : battery switching with the proposed antagonist lay out as a solution remains to be validated
- Additional XY reference on the mechanism housing in order to improve battery positioning on the vehicle before locking
- Resistance to the external environment (water, mud, dust, grave, frost)
Given the multiple benefits it brings (switching time performance, BSS cost reduction, process tool standardization), the EASYBAT team considers this solution viable and able to be the future standard, not only European but also worldwide, and could be a reference for its future switchable battery projects.
Standardization
The CEN-Cenelec workshop agreement (CWA) report has been drafted as a collaboration of contributing partners under the EASYBAT consortium and additional stakeholders. This CWA mainly describes the battery swap process, the EASYBAT system architecture and interfaces (mechanical, electrical, cooling and data interfaces), excluding all safety items as requested by some countries during the international consultation. This CWA is essential to prepare standardization which is inescapable for EV, battery and BSS interoperability. It may lead in the future, to a standard to be developed when the need will be confirmed by the development of new systems by car manufacturers and battery swap service providers.
Potential Impact:
Strategic impact
The strategic objective "GC.SST.2010.7-4: Smart storage integration" lists the impact of the battery smart storage integration at four different levels: environmental, cost, logistic and life cycle. As described in the different following sections (technological, socio-economic and environmental), the EASYBAT project addressed each of these levels of impact.
Technological Impact
''Advanced battery technology is one of the most important technical issues being addressed by Alliance members today''. — Robert Strassburger, Vice President of Safety and Harmonization of the Alliance of Automobile Manufacturers.
The EASYBAT project established models and generic interfaces for the safe, fast and automated exchange of battery systems. For all interface types concerned, cooling medium, electrical high voltage and mechanical fixation, we derived the existing technologies towards automotive qualified solutions that outperformed existing technologies and standards.
EASYBAT's technological impact is significant in a number of fields:
Communication interface between an electric vehicle and its battery:
Today, batteries are connected and disconnected manually, which greatly impedes their wider diffusion as it implies a delicate and long process. EASYBAT developed generic plug-and-socket connectors with safety locking mechanism that can be connected and disconnected in an automated way without any manual interaction
Connectors
In today's EVs and HEVs the batteries are fixed by screws once in a lifetime, which prevents them from withstanding a high number of connect / disconnect cycles in an engine compartment environment. EASYBAT developed an automated, automotive proof hose connect / disconnect mechanism that can operate several thousands of cycles without manual interaction. EASYBAT provided a standard mechanism applicable to the mass market.
Cooling
The cooling of EV batteries is usually done by liquid cooling media. EASYBAT developed the usage of a common gaseous cooling media for vehicle and batter.
These elements, as well as the safety guidelines for battery, battery packaging, swapping mechanism and the design rules for battery, and EVs' interfaces, developed in EASYBAT form the technological base for the European wide implementation of EVs as general purpose cars. The highest technological impact is on European car manufacturers and swapping mechanism providers. The main benefits are as follow: The technological benefits EASYBAT can bring to OEMs are the product safety, a standardization that will leave a maximum flexibility in vehicle design, and the possibility to increase the drive dynamic performance. The benefit EASYBAT brings to swapping mechanism providers are the product safety, a base for the design of swapping kinematic, and a standard for electrical and mechanical interface on swapping kinematic side.
Socio-economic and environmental benefits of the project
"The battery is the cleverest and most expensive part of electric vehicles ." It is also the technical element that will constrain the range an electric vehicle can cover. Yet, price and range are precisely the two foremost issues hindering the wider adoption of electric vehicles by automakers and end-users.
Economic benefits
In terms of EVs cost
EASYBAT offered models and generic interfaces for a battery integration system that drive the path to standardization, making the battery swap cost effective. EASYBAT's definition of standardized interfaces between the vehicle and the battery allows to mass producing electric vehicles batteries, reducing the global cost of EVs, and turning them into a realistic and affordable solution. Moreover, the battery integration system standardization gives to Europe a comparative advantage over Japan and the U.S where standards are still to be defined.
Moreover, thanks to generic interfaces and to the battery management system (BMS), batteries are used in an optimized way, which enables battery economies, which in turn trigger a lower consumption of batteries, and some energy savings.
In terms of EVs range extension
Another major advantage EASYBAT provides is a solution to the "range anxiety", which currently hinders the EVs market growth. "Range anxiety" refers to the fear of being stranded by an electric car because of insufficient battery performance or charge; it is related to the limited range EVs can offer.
EASYBAT's goal was to create interfaces for batteries which can be completely re-charged via three processes: a standard charge (which takes between four and eight hours), a battery swap (which takes less than five minutes), or a quick charge (which recharges the battery to 80% state of charge in 20 minutes). Contributing to defining interfaces for an easy battery integration and removal, EASYBAT helps avoiding the "range anxiety" among car users, and unleash the EVs market development
Social and environmental benefits
EASYBAT offers a maximal environment protection: zero emission
The necessity to explore electric cars other than the conventional combustion engine is driven by the cost these vehicles entail in terms of petrol consumption – this is true especially during peaks such as the one that happened during the summer 2008, when the price of oil spiked to more than 150 US$ per barrel. However, while the oil prices can fall, as they have done since 2008, climate change concerns compel manufacturers to continue searching for technologies that would not trigger any damage the environment. This was made clear by governments during the United Nations Climate Change conference that recently took place in Copenhagen.
Today, plug-in hybrid vehicles provide a solution to reduce CO emissions. Preliminary studies recently performed showed that replacing ICE vehicles by plug-in hybrids would trigger a CO2 reduction included in a range of 28 to 67 million Euro per year in the various scenarios and at a CO2 price of 14.8 Euro per ton, or 42 to 139 million Euro per year in the various scenarios at a CO2 price of 50 Euro per ton.
Taking those results a step further, replacing ICE’s with vehicles with a swappable battery (EASYBAT's preferred application) together with switching stations that use renewable energy can secure an environmental benefit of 113 million Euros per year at a CO2 price of 14.8 Euro per ton or 270 Euro per year at a CO2 price of 50 Euro per ton.
EASYBAT's vision on the long term entails the use of renewable energy to exchange a battery at a switching station. This enables EVs to accelerate the transformation of charging stations into sustainable power generation slots. A study of the renewable energy power demand necessary to charge EVs was performed by the Institute for Energy Economy and Application Technology (IfE), at the Technical University of Munich. This study concluded that the charging of batteries at battery swap stations enables to leverage more renewable energy in the provided charging power mix than in any other way of charging EVs. Therefore, EASYBAT's vision on the long term is highly beneficial to the environment: not only it reduces CO2 emissions by offering a zero emissions alternative to ICEs, but it also triggers the leverage and storage of renewable energy in charging stations.
Added Value at the European level
To remain a leader in the field of green cars, Europe has to offer innovative batteries systems to suit electric cars from technological and commercial perspectives. The EASYBAT project is led by partners representing different European countries, and covering the full range of activities necessary to achieve the integration of a new battery system in electric vehicles. The EASYBAT's project therefore lies on European OEMs and end-users' needs, and is validated in its European environment. The EASYBAT solution's adoption by European OEMs and end-users is also faster since it is offered across Europe, increasing the market acceptance at the European level.
This European feature has many positive outcomes. Firstly, EASYBAT proposes a generic battery integration model which could set a base for a European standardized battery, increasing the batteries' interchangeability and improving their batteries interoperability among European OEMs. Secondly, as EASYBAT offers a generic battery interface which allows the production of generic battery on large scale at an affordable price..
Furthermore, EASYBAT proposes a pan-European solution. The batteries interfaces developed by EASYBAT take account models in which the battery can be completely re-charged via a standard charge or changed in less time than it takes to top off an ICE (internal combustion engine) car with petrol. The range extension potentially provided by such a solution is unlimited. Therefore, it allows European drivers to drive through Europe without any technical restrictions.
EASYBAT has the capacity to contribute to the preparation of standards, homogenized across Europe, while developing synergies between various actors and contributing to new business models that can take advantage of interchangeability and full interoperability. Therefore, EASYBAT helps strengthening Europe's position as a leader in the competitive green cars industry.
Contribution to standards
The CEN-Cenelec workshop agreement (CWA) report has been drafted as a collaboration of contributing partners under the EASYBAT consortium and additional stakeholders. This CWA mainly describes the battery swap process, the EASYBAT system architecture and interfaces (mechanical, electrical, cooling and data interfaces), excluding all safety items as requested by some countries during the international consultation. This CWA is essential to prepare standardization which is inescapable for EV, battery and BSS interoperability. It may lead in the future, to a standard to be developed when the need will be confirmed by the development of new systems by car manufacturers and battery swap service providers.
List of Websites:
http://www.easybat.eu/