EDENenergy, a start-up in Freiburg, Germany, spun out of the Fraunhofer Institute for Solar Energy Systems ISE, has delivered its first stationary storage system built from used e-scooter batteries. The 70-kilowatt-hour unit contains 112 second-hand packs and went to a customer in mid-October. Electrive says the packs are wired in series, which works out to an average of about 0.6 kilowatt-hours per battery. Fraunhofer ISE announced the company’s approach on Nov. 2.
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About one million powerful e-bike and e-scooter batteries are discarded early each year in Germany, according to the Fraunhofer ISE release, and many still hold most of their original capacity. EDENenergy wants those cells working in commercial buildings that already have solar panels but no way to store the power they produce.
Power electronics that skip the teardown
The central claim concerns method. Fraunhofer ISE says in its release that a flexible power electronics system developed at the institute connects batteries of different types, so that, in co-founder Florian Bierwirth’s words, different storage units can be combined without the batteries having to be taken apart. Electrive’s account describes the same design: the electronics let batteries with different form factors and different battery management systems work together, with the packs staying whole.
Variety still has a cost. Bierwirth told InsideEVs that connectors, battery management and communication protocols differ from one model to the next, and that e-bikes in particular come in a wide range. For now the company relies on large suppliers that can deliver big batches of a single battery type, and adding each new type means adapting the interfaces. A 70-kilowatt-hour box built this way is a pilot of the method, not a catalog product, as the InsideEVs report lays out.
Stationary service helps the second life. InsideEVs notes that a battery bolted into a storage box does not face the vibration and large temperature swings it saw on a scooter, and that a solar inverter is mounted on one side of the cabinet. Capacity stays at 70 kilowatt-hours because unusable modules are replaced rather than tolerated.
Testing 350 batteries and holding 70 kilowatt-hours for a decade
EDENenergy planned around 80% remaining capacity, a state-of-health assumption common in second-life projects. Among the first 350 batteries it tested, many measured well over 90%, Fraunhofer ISE says. Manufacturers typically guarantee only 80% of original capacity after 10 years, and the start-up aims to keep its storage unit at 70 kilowatt-hours for that long by replacing individual modules. Modules are monitored remotely and can be swapped while the system keeps running; retired ones go to recycling partners, where materials are reused where possible. The company says that by replacing modules it can hold overall capacity at a constant level even after 10 years of operation.
Batteries come mainly from large e-bike and e-scooter fleet operators, and each one is screened before it is connected, according to pv magazine.
Customers, subsidy and the 300-kilowatt-hour plan
The first target market is small and medium-sized businesses in the region that have photovoltaic systems but no storage, using the batteries to raise self-consumption or cut peak loads. Municipal utilities and electricity trading are named as possible later uses. A Baden-Wurttemberg program called Mittelstand trifft Start-ups can cover 50% of the cost for participating regional businesses. A larger system of up to 300 kilowatt-hours is planned, a figure that implies the same 0.6 kilowatt-hours per module, which InsideEVs says would use roughly 500 second-life e-scooter modules. Electrive adds that EDENenergy is seeking pilot customers in the regional commercial sector and also receives support from the Sustainability Performance Centre.
Three co-founders, Bierwirth, Daniel Seeger and Hannes Kurzmann, previously worked in the power electronics department at Fraunhofer ISE, and three part-time staff have since joined. Ulrich Prediger, a co-founder of the bike-leasing firm JobRad, is the first investor through the state’s BW Pre-Seed program. The University of Freiburg’s innovation page for the venture lists Prof. Sonia Dsoke as academic mentor under an EXIST start-up grant, advising on battery aging and diagnostics, with Bierwirth listed as the contact, and notes that the central research question is how reused cells can be assessed quickly and safely.
The Freiburg research page frames the engineering problem. Reused cells need a fast, reliable state-of-health assessment to run safely in a second application, and the venture is studying what defines the end of life for a second-life battery in stationary use and whether lower current profiles and smarter operation can slow degradation. The page puts the number of e-bike and e-scooter batteries discarded each year at “millions.”
No price, warranty or named customer has been published. The promise that matters most, a storage unit that still delivers 70 kilowatt-hours after ten years of module swaps, can only be tested once the first system has run for a meaningful stretch. InsideEVs frames the storage as affordable, yet its report offers no cost figures to check that against.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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