A shielded cell, cables come from the ceiling. An employee leans over the open housing on the lifting table, connects connections. “This is our high-tech clinic for batteries,” says Markus Grassmuck, head of the Rüsselsheimer Battery Refurbishment Centers (BRC). It is not operated on here – repairs are made here. What exactly is defective shows the incoming analysis – cell damage, electronics problem or software error. The aim is to repair the lithium-ion battery again. In the middle of the factory premises, the latest technology on 1,000 square meters.
In the center-it belongs to Opel Special Vehicles-defective batteries of all stellatis brands are opened, checked, repaired and sealed again. In a well -rehearsed process. It all started in 2011: two employees, one type of battery, a model – the Opel Ampera. Today Grassmuck’s team looks after batteries of a growing electric fleet: from Opel, Peugeot to Fiat, DS or Jeep. The energy stores land here from all over Europe – by forwarding from the central warehouse in Vesoul, French.
“Diagnosis, repair, test cycles, current software – we ensure that batteries get a second life.”
– Markus Grassmuck –
Well-rehearsed process: After diagnosis and repair, complex capacity and performance tests follow.
Lord of the high-tech clinic: Markus Grassmuck heads the Rüsselsheimer Battery Refurbishment Center.
Hair rupture? Burned backup? A weakening cell? A lot of experience is required to determine where the problem is.
The employees are specialists who work on the open batteries under the highest level of 5 security standards.
Modern high-voltage batteries are more durable than once assumed-a result of modern battery management systems.
A failure of a battery? Only occurs very rarely. And if it does, there is a team in Rüsselsheim that finds and fixes mistakes. “Even those who live on the Faröer Islands get their electric car repaired briskly,” says Grassmuck. The path is clearly defined: the workshop reports a mistake. The battery goes out, an equivalent comes in – often even with better condition than the old one. The defective copy is sent to Rüsselsheim, restored there and then goes back to Vesoul – ready for the next use. A circulation that works. Because it is organized precisely. And because specialists work in the M55, all with high-volt-level 5 training-the highest safety standard for work on open batteries.
The actual mistake, says Grassmuck, usually hides well. Error codes from the workshop, but also your own measured values are often only indications – symptoms, no diagnoses. “We get a detailed picture,” he explains. A lot of experience is required. It is opened, checked, researched: Are they the modules? The control units? A hair tear? A blasted fuse? Or just a cell that is weaker than the rest? If a module consisting of several cells has to be exchanged, it goes into the “wine cellar” – as they call the camp here. Here modules of different “maturity degrees” are kept here. Because a battery is a sensitive system. New modules must match the state of charge and the capacity of the old ones.
“Even those who live on the Faröer Islands get their electric car repaired quickly-thanks to the well-rehearsed circulation.”
– Markus Grassmuck –
Guaranteed performance oples grants a guarantee of 8 years or 160,000 km on the batteries of its electrical models-like all Stellantis brands-depending on what occurs first. This guarantee applies to at least 70 percent of the original charging capacity of the battery. The Rüsselsheim manufacturer also offers a free battery capacity test as part of regular maintenance. A battery capacity certificate that confirms the vehicle’s battery charging capacity makes it easier to resale.
Modern high-voltage batteries are significantly more durable than once assumed-a result of modern battery management systems. They protect the batteries from overheating, deep discharge and other harmful influences. The practical experience in the BRC shows: “Even after several hundred thousand kilometers, batteries still have a large part of their original capacity,” says Grassmuck. Around 20 percent of the capacities in Halle M55 are currently on batteries that are repaired on site and then go back directly to the customers. The vehicles arrive completely – from workshops within a radius of up to 300 kilometers.
Sustainable battery logistics
The majority of the work, however, affect the exchange processes, i.e. those developed batteries that are sent via the central warehouse in Vesoul. Still. The perspective goal is to repair the workshops – with decentralized repairers across Europe. There are 20 of them today. There are more to be more that runs electromobility offensive. In the meantime, Stellantis has opened a second Battery Refurbishment Center in Turin. South batteries there, North batteries to Hessen-logistically efficient and environmentally conscious.
A module that is no longer suitable for vehicle but still provides enough energy gets a new task. For example as a stationary memory. The tour of the battery clinic shows how much high-tech, know-how and passion is in the heart of electromobility that is not a black box-but repairable. Almost always. In the end, a repaired battery in a wooden box leaves the hall. Sealed, tested, fully charged – ready for your second life.
August 2025
Text: Eric Scherer, photos: Rudolf Mehlhaff