Battery
Battery Passport Granularity: Cell, Module, Pack
At which level is a battery passport kept? Pack, module and cell identifiers, what the cell supplier hands over, and how a module swap in repair is recorded.
The EU Battery Regulation wants a Digital Product Passport for each individual battery: from 18 February 2027, every EV, LMT and industrial battery above 2 kWh placed on the market carries its own record, bound to a unique identifier. That is item level, the highest of the three levels in DPP granularity; the model or batch level debated in textiles or furniture is not an option for batteries.
The real design question starts one layer down. A pack holds dozens of modules, a module dozens of cells, each possibly from a different supplier. The passport belongs to the pack, but most of what it declares is derived from module and cell data.
What is the unit of the passport?
The regulation defines the passport content in two layers: information about the battery model (chemistry, rated capacity, carbon-footprint class) and information specific to that battery (manufacturing date, serial number, state of health). Each unit therefore needs its own record, but model fields are shared: one model record, thousands of unit records.
Which batteries fall under the duty is covered in scope and obligated parties; this article is about the structure underneath the unit record.
Three levels, three identifiers
| Level | Typical identifier | Data owner | Place in the passport |
|---|---|---|---|
| Pack (battery) | GTIN + serial (SGTIN) or GIAI, inside a Digital Link URI | Pack maker / operator placing on the market | The passport itself |
| Module | Manufacturer serial, linked to the pack record | Pack maker | Composition and dismantling data, replacement log |
| Cell | Cell maker's batch and serial code | Cell supplier | Chemistry, critical raw materials, carbon and recycled-content inputs |
| BMS | Hardware serial + firmware version | Pack maker | Source of the dynamic data |
An LMT maker with a retail channel appends a serial number to the GTIN (AI 21) and uses the GS1 Digital Link structure; for industrial packs tracked as individual assets, a GIAI is more natural. In both cases the unique identifier rules of EN 18219 apply: globally unique, persistent, machine-readable. The regulation also requires the QR code to link to the unique identifier assigned by the operator placing the battery on the market; once printed, it cannot change.
No global scheme is mandatory for modules and cells, but they must be unique within the pack record. Practical rule: keep the cell supplier's code as delivered; do not overwrite it with your own.
What must the cell supplier hand over?
The heaviest public-tier fields are the ones a pack maker cannot produce from its own records: cell chemistry, cobalt, lithium and nickel content, recycled-content shares and the cell-manufacturing part of the carbon footprint. Annex XIII defines them per model, but the evidence sits with the cell batch.
The minimum set to request from the supplier:
- Cell model and batch code, per delivery.
- Chemistry and critical raw material content, per model.
- Recycled-content declaration and its basis, per batch.
- Carbon-footprint inputs or a finished calculation, per model.
- Hazardous substance and safety information.
The supplier data collection process covers putting this list into the contract and a template. The pack maker's job is to bring batch-level data down to unit level by recording which batch went into which pack; the bill of materials and production records make that link.
What happens when a module is swapped in repair?
The passport is bound to the pack, whose identity does not change with repair. When a module is replaced, the correct operation is not to correct the record but to add a new version: the module removed, the module fitted, the date and the party performing the work. The previous version stays readable; this is audit trail and versioning applied to a battery.
The boundary: once the operation reaches the regulation's threshold for remanufacturing or repurposing, it is no longer repair; the battery is placed on the market as a new product with a new passport linked to the original. See second-life batteries and passport continuity.
Label and data carrier
Item level means a unique QR on every pack; on a series production line, the label printer has to talk to the passport system. Modules and cells need no QR; their identity lives inside the pack record. See battery labelling and QR codes for print, placement and symbol rules, and the battery passport guide for the overall framework.
Frequently asked questions
Does every cell need its own passport?
No. The passport belongs to the battery placed on the market (a pack, or a module sold on its own); cell data is carried inside that record at model and batch level.
Can I use my internal code as the battery serial number?
Not on its own; it has to sit inside a globally unique scheme. The most common route is embedding the GTIN plus serial number in a Digital Link URI.
Who records a module replacement in the passport?
The repair operator produces the data; the economic operator responsible for the passport, or the service it has authorised, writes it as a new version. Define that flow in the contract.
