Stuttgart, Germany cell grading plant
How Stuttgart — Baden-Wurttemberg Grading Works decides reuse or refining for every module — test sequence, grade bands, outputs and the sites that feed it.
Throughput
28,000 TPA
Process stages
6
Feeder sites nearby
6
Operating since
2016
From intake to grade assignment
- 1
Intake & safety triage
Packs are logged, thermally imaged and screened for swelling, coolant ingress or venting before entering the bench area.
- 2
Controlled de-energising
Residual energy is discharged to a safe state of charge with regenerative load banks and recorded per serial number.
- 3
Module-level capacity test
Full charge-discharge cycling at C/3 establishes usable capacity, internal resistance and cell-to-cell balance.
- 4
EIS fingerprinting
1 mHz–10 kHz impedance sweeps separate SEI growth, lithium plating and contact resistance degradation modes.
- 5
AI optical inspection
Machine-vision inspection of busbars, welds and cell cans flags mechanical defects that block second-life reuse.
- 6
Grade assignment
Grade A (≥85% SOH), B (75–85%), C (65–75%) and D routes are assigned, with D-grade material released to refining.
Acceptance criteria
| Criterion | Requirement |
|---|---|
| Accepted feed | Whole packs and modules from intake yards and fleets |
| State of charge | Below 30% on arrival, recorded per serial |
| Condition | Damaged units declared and routed to quarantine |
| Documentation | Manifest with serials, chemistry and prior history |
Grade bands and routes
| Grade | Route |
|---|---|
| Grade A (85%+) | Grid-tied and commercial storage builds |
| Grade B (75–85%) | Telecom backup and solar buffering |
| Grade C (65–75%) | Low-duty backup, short warranty |
| Grade D (<65%) | Discharge and refining feed |
Why Stuttgart, Germany
Stuttgart is home to several premium vehicle makers and a dense network of engineering suppliers across Baden-Württemberg. The grading works opened in 2016, the network's first European diagnostics site, and with 28,000 TPA of capacity it remains one of the largest. Its early start means it has tested European pack designs through several generations of technology. Supplier returns are a steady part of its work.
The works focuses on premium passenger-car packs, engineering test and validation packs, and supplier returns. Premium platforms often use complex high-voltage architectures and tightly integrated cooling, so the team's experience with them shortens disassembly time and improves the accuracy of module-level grading. Material below reuse threshold is consolidated and sent to integrated campuses for black mass production, and grade reports are issued for every unit tested.
Permitting
EU Battery Regulation (EU) 2023/1542 and national implementing law
The works operates under German environmental permitting and battery law aligned with the EU Battery Regulation (EU) 2023/1542. Transport follows ADR rules for dangerous goods, including the special provisions for damaged or defective lithium batteries.
Technical strengths
First European grading site
Operating since 2016, with data across several pack generations.
Premium platform expertise
Experienced with complex high-voltage premium architectures.
Supplier engineering support
Grades returned units so suppliers can understand failure patterns.
Sites that feed Stuttgart, Germany
Packs and modules arrive from these intake sites.
Stuttgart, Germany plant: technical questions
How long does grading take?
Standard passenger modules are graded within about five working days of intake; large-format bus and truck packs take longer because of disassembly.
What tests are run on each module?
A full capacity cycle, DC internal resistance, impedance spectroscopy and optical inspection of busbars, welds and cans.
Does Stuttgart grade test packs?
Yes. Engineering and validation packs are a regular part of its intake.
How long has the Stuttgart site operated?
Since 2016, making it the network's first European grading works.
Damaged or defective packs are handled under a separate quarantine protocol — flag them in the form and the team calls you back the same day.
Need modules graded?
Share pack counts, chemistry and condition for a grading slot and indicative value split.