The digital battery passport is usually discussed as an IT or compliance topic: a QR code, a cloud platform, a data model. For anyone building or buying a battery pack line, it is first of all a manufacturing topic. A large share of the data the passport has to hold, such as the identity of each battery, where and when it was made, its weight, its measured capacity and the cells inside it, is created on the shop floor. If the line does not capture that data per battery, no passport platform can make it up later.
This article explains what the passport is, which energy storage products it covers, and what it means for each part of a pack line and its manufacturing execution system (MES).
What the battery passport is
The EU Batteries Regulation, Regulation (EU) 2023/1542, requires an electronic record for each individual battery placed on the EU market or put into service, from 18 February 2027 (Article 77). The record is reached through a QR code on the battery, which links to a unique identifier for that battery. The passport has to stay available after the battery leaves the factory, and a new passport, linked to the original, is created when a battery is repurposed or remanufactured.
The obligation applies to three categories:
- industrial batteries with a capacity above 2 kWh,
- electric vehicle batteries,
- light means of transport (LMT) batteries, such as e-bike and e-scooter batteries.
Stationary energy storage counts as an industrial battery. In practice, almost every residential ESS pack, C&I cabinet and utility-scale container sold in the EU from February 2027 needs a passport.
The duty sits with the economic operator that places the battery on the market. For a company that assembles packs or cabinets in Europe from imported cells, that is usually the company itself, not the cell supplier. It needs the cell supplier's data, but it carries the obligation.
What goes into it
Annex XIII of the Regulation lists the content and splits it into three levels of access:
| Access | Examples of content |
|---|---|
| Public | Manufacturer, battery category, unique identifier, place and date of manufacture, weight, chemistry, rated capacity and voltage, expected lifetime, carbon footprint, recycled content, hazardous substances |
| Persons with a legitimate interest (repairers, remanufacturers, second-life operators, recyclers) | Detailed composition, component part numbers, dismantling instructions, safety measures |
| Authorities and the Commission | Test reports that show compliance with the Regulation |
Some of these fields are static and come from engineering or from suppliers. Others are different for every battery and can only come from the production line.
Where the data is created on a pack line
The table below follows a typical ESS pack line from cell intake to packing, and shows which passport data each step produces and what the line needs for it.
| Line step | Passport data it feeds | What the line needs |
|---|---|---|
| Cell intake and inspection | Chemistry, materials, recycled content, carbon footprint of the cells, due diligence on raw materials (all via the cell supplier) | Scan every cell's code and link it to the supplier's lot and its data set |
| Cell sorting (OCV/IR) | Basis for pack-level performance values | Store the measured values per cell, not only the grade |
| Module stacking and welding | Composition of the battery, cell-to-module genealogy | Record which cell sits in which module and position; store weld results per module |
| Pack assembly (BMS, CCS, cooling, harness) | Component part numbers, dismantling information | Record the as-built bill of materials: actual part numbers, revisions and supplier lots |
| End-of-line test | Rated capacity, voltage, internal resistance, power capability, round-trip efficiency | Keep the measured values per serial number and the test program version, not only pass or fail |
| Weighing | Battery weight | An in-line scale, with the result stored per serial number |
| Marking and labelling | Unique identifier and QR code | A durable mark that lasts the battery's life, checked by a reader before the battery leaves the line |
Two fields are worth a closer look, because they reach beyond single stations.
Carbon footprint
The carbon footprint declaration is calculated per battery model and production site, and the cells usually make up most of it. The pack plant's own share comes from its energy use. A line that meters electricity and compressed air per line or per area, and an MES that counts output for the same periods, makes this share far easier to calculate and defend. The dates for the carbon footprint rules depend on implementing acts from the Commission, so check the current timetable before planning around them.
Due diligence on raw materials
The supply-chain due diligence obligations for cobalt, lithium, nickel and natural graphite were postponed to August 2027. For a pack maker they are mostly a purchasing topic, but the line still has a role: due diligence information only reaches the right battery if the cell lots are traced.
What it means for the MES
The MES is where all of this comes together. It does not have to host the passport itself; that job usually goes to a specialised passport platform. But it must deliver a complete and trustworthy data set for every battery to that platform. In practice that means:
- Serialization at every level. Cell, module, pack and, for C&I, cabinet each get an identity, and every station scans before it works.
- Full genealogy, including rework. When a cell or module is replaced after a failed test, the record has to show the new part and drop the old one. Rework is where genealogy most often breaks.
- Measured values, not only verdicts. Many lines store only pass or fail at end of line. The passport needs the numbers.
- Interlocks. A pack with an incomplete record should not reach the packing station.
- An export interface. A defined data format and API towards the passport platform, plus the supplier data coming in from the cell maker.
- Retention. Batteries in stationary storage typically run for around 10 years. Plan storage and archiving for the life of the product, not for the warranty period.
The passport is filled in on the shop floor. A line that only records pass or fail will leave gaps that no software can close later.
New lines and existing lines
For a line that is still being specified, passport readiness costs little: a few extra scanners, a scale, a marking station chosen for durability, and an MES scope that includes genealogy and data export. It is far cheaper to write these into the specification than to retrofit them.
Existing lines often have gaps. Common ones are cells that are not scanned at intake, rework stations outside the MES, end-of-line testers that only report pass or fail, and labels that will not survive years in a cabinet. A short gap check of each station against the table above shows what has to change before February 2027.
The battery passport is one of several requirements of the EU Batteries Regulation that reach the factory floor. We will cover the others, from labelling to carbon footprint, in a follow-up article.
Planning a pack line for the EU market?
Montavo designs battery pack and ESS lines with traceability and MES architecture built in from the first layout. Explore a line in the configurator, or ask us to check an existing line for passport readiness.