BATTERY LIFE PROJECT
Maritime Battery Life is about enhancing the operational life of batteries in electric ferries. This is achieved by advanced cycling and aging tests on battery packs coming from the prototype E-ferry Ellen.
The EU funded Ellen has battery cells originating back from 2018. Ellen has held the world record for travelling distance of pure electric ferries for many years. Her batteries have seen heavy duty cycling from morning to evening. Degradation is not distributed evenly between battery modules. Thus, lifetime extension strategies are urgently needed, closing in on the first decade of operation.
The Battery Life project first phase was finding ways to upcycle some of best cells as spares for the reuse in Ellen and other ferries using Leclanché system and to repair battery modules for these vessels. For this, new hardware and software tools was developed in the first phase of the project. The focus was on tootls that can be used when ferry is still in operation and involvement of ferry's maintenance crew in the process to bring down cost and optimize performance. This way Battery Life project in its first phase has already identified and proved strategies for repair and lifetime extension of single battery modules in an electric ferry.
In next phase of the project, called Battery Life BESS Pilot or just second phase results and methods must be scaled to cope with the large volume of batteries taken out of the Ellen ferry during its battery system exchange in spring 2026 and in general the increasing volume of aging batteries from other battery ferries. Thus, used battery modules from another local ferry and the battery supplier Corvus have also arrived in project lab to compare needed processes and work to ensure a generic approach to the challenge.
Project first phase also identified medium degraded cells from battery modules which were deemed to be at a too low State of Health (SoH) to stay in the vessel. In second phase of the project, these medium degraded cells are upcycled and preparred locally for second-life applications and reuse in onshore containers, e.g. balancing the grid at ferry operators' charging stations.
The upcycling is performed locally with a philosophy of devolping safe but simple procedures and mobile equipment for testing and cycling. The local approach increases sustainability and lowers costs, removing the need for long distance transport of battery materials which are normally classified as dangerous goods with risk of environmental hazards.
Research partnership however, is based on both a local, regional and international approach. Project partners are collaborating with battery suppliers from Switzerland, Sweden and Norway, with technology experts from research and educational institutions including the Danish Technological Institute (DTI), University of Southern Denmark (SDU) and its Center for Industrial Electronics (CIE), the Aarhus School of Marine and Technical Engineering (AAMS), and last, but not least, the local ferry operators, suppliers and center of battery-electric ship operation at Marstal Navigationsskole (MARNAV).
Phase One (feasibility study battery management)
Step 1
Battery cycling tests of used cells under laboratory conditions will provide feasibility study for improved Joint State estimations. Better State of Health understanding will improve safety margins. The research forms the basis for development of new hardware and software tools and procredures for battery life extension.
Phase One (feasibility study battery refurbishment)
Step 2
Feasibility study to develop local facilities and competences for battery cell analysis, module refurbishment and second-life approval procedures. Philosophy for and demonstration of safe and simple mobile test and cycling procedures. Workshop facilities are developed and tested on single modules from battery ferry.
Phase Two (Upscaling and development of facilities)
Step 3
The upscaling of battery module refurbishment requires proof of concept and some development of integration systems for the battery modules to be reused in land based Battery Energy Storage Systems (BESS) at ferry charging station. In this step development of the Energy Management System and planning of the BESS including site preparation and approvals is carried out. Certification procedures for land based use of the maritime classed system and test of grid compliance collaborating with Partners and Authorities will be vital to achieve this goal.
Phase Two (Demonstration and dissemination)
Step 4
Refurbished and upcycled battery modules is preparred and installed in prototype Battery Energy Storage System at site connected to the ferry charging station. Scaling of testing and cycling of modules is demonstrated and principles for the combined operation of BESS and ferry charging system is developed based on prototyping. Education of crew and maintenance personnel and dissemination via scientific articles, conferences, courses and network activities will proceed, e.g. via the continued membership of and participation in Danish Center for Energy Storage (DaCES) and the Maritime Battery Forum (MBF).
Battery ferries on the rise
More than a dozen new battery ferries are being designed right now, just to serve local and regional routes in Denmark.
Within a decade a vast amount of used batteries could become a sustainability issue if not dealt with in a timely manner.
Enhancing the operational lifetime of the battery cells, and doing it locally, will better compensate the environmental impact from cell production and mining of raw materials..
If successful, the Battery Life project will repay early adopters for some of the challenges they have faced, pioneering the way of using batteries at sea by improving economic lifetime of their procured battery cells.
At the same time future battery ferries will benefit from the knowledge gained from these early adopters – like the Ellen ferry
Impact on battery cycle life
Danish Technological Institutue and SDU Center for Industrial Electronics
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By testing and modelling SDU and DTI will provide improved joint state estimations and SOH for enhancing battery life onboard the battery-electric ferries.
Battery cells will not age evenly inside battery modules. Small initial differences will grow, especially in tough applications like ferry operation with frequent supercharging. When differences after many years can no longer be balanced out in operation, then battery modules need to be refurbished.
Identifying rougue or poor cells and monitoring thousands of battery cells on a continous basis becomes increasing important when cells are aging. For this task, new hardware and software tools are being devolped based on the research done by the technology partners.
Feasibility of a "second-life" in land based application
Local Ferry operator - Ærøfærgerne, and Municipality of Ærø, Marstal Navigationsskole and Aarhus School of Maritime Engineering
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Battery cells from different modules can be redistributed to obtain a better match in refurbished modules and best modules will go back into the vessels as important spare modules. Others will have a second-life elsewhere in land based applications.
In the demonstration project the maritime battery system will be tested in a Battery Energy Storage System (BESS) in the port of Søbyl connected to the charging station for the ferry and providing flexibility and savings for the operator and better local grid balance, smoothing out the peaks.
The local approach and collaboration between ferry operator, Municipality of Ærø, local companies, like Søby Skibselektro, players in grid, like the local Energy Community of Ærø will ensure increased sustainability of battery operation and lower costs through savings and at the same time enhance operational lifetime on Ærø of the procurred batteries.
Project plans and progression
Battery Life first phase has been fully funded and step 1 and 2 are nearing finalisation as planned.
Battery Life second phase - the BESS Pilot demonstration project and step 3 and 4 have been partly initiated with feasibility study from first phase, pre-projecting and the application for required funding.
Invasive module test and capacity test of cells has been performed by the DTI and SDU CIE, some test is still in the works. DTI has developed improved tools and procedures for calibration and SOH estimations. A large number of battery modules have been disassembled by Søby Skibselektro and Ærøfærgerne based on results coming from SDU CIE and DTI Lab investigations.
Test facilities and mobile test and cycling equipment in Søby and Marstal on Ærø have been developed and used for battery cell testing, including EIS test and corrosion test on single cells and pouches. Also refurbishment of sample battery modules originating from the Ellen ferry has been performed with these going back into maritime operation on the ferry increasing State of Health of the overall system.
The work has been performed in a collaboration between all project partners and associates according to plan including DTI, SDU CIE, Leclanché, Søby Skibselektro, Marstal Navigationsskole, Ærøfærgerne and assistance for feasibility studies from local Energy Community on Ærø. Aarhus School of Maritime and Tehchnical Engineering has joined the Battery Life project during first phase delivering data collection system and competences for the analysis of operational battery data. They are also a vital partner for tasks in the second phase of Battery Life - the BESS Pilot project.
Dissemination of initial results of battery and cell testing at SDU has been published in scientific article and at conferences and network orginsations including MARIKO, Maritime Battery Forum, DaCES, Færgesekretaratet, Skibsteknisk Selskab, IDA, Blue Tech Center, DANIDA Fellowship Centre and Maritime Research Allinance, Interreg - Smart Power Conversions programme and the many battery educational courses completed and performed by the partners.
Battery Life Project Partners
In-kind associated partners for phase one
