Battery passport for grid-scale and residential energy storage
Multi-megawatt-hour containers and home batteries are treated the same way by the Regulation. Both are industrial batteries — 36 mandatory data points, a 2 kWh threshold — and the real design question is the granularity of the passport.
Industrial battery above 2 kWh — 36 of 71 data points mandatory
on 18 February 2027
Regulation (EU) 2023/1542 places energy storage batteries in the industrial category, including where they are installed in a private or domestic environment. A 5 kWh residential storage system therefore falls under the same regime as a multi-megawatt-hour container: 36 of the 71 data points mandatory on 18 February 2027, as soon as capacity exceeds 2 kWh.
Applicable threshold. The 2 kWh threshold is decisive on this segment: it excludes very small systems, but covers virtually every residential product on the market, which generally starts above 3 kWh.
Source: Regulation (EU) 2023/1542 and the European Commission guidance document "Digital Batteries Passport – data points by category", version 2.0 of 15 August 2026, which lists 71 data points and their applicability by battery category.
What is in scope, and what is not
Subject to the passport
- Grid-connected containers and storage systems (BESS)
- Residential and commercial site storage above 2 kWh
- Storage batteries paired with photovoltaic generation
- Replacement modules and capacity extensions placed on the market after 18 February 2027
Out of scope
- Systems of 2 kWh or less, outside the passport obligation
- Traction batteries, which fall under another regime even when they end up in stationary storage — their original passport follows them
What you actually have to produce on 18 February 2027
Not every data point in the passport is due when it opens. The Commission guidance distinguishes, for each battery category, what is mandatory at the deadline from what is still waiting for its legal framework. Scoping the project against the full list means over-investing; ignoring the distinction means rebuilding in two years.
Mandatory at the deadline
- ✓Unique identifier and economic operator identifier, at whichever level is the unit placed on the market
- ✓Manufacturer, model, date and place of manufacture
- ✓Cell chemistry, critical raw materials and hazardous substances
- ✓Capacity, power, round-trip efficiency and expected cycle life
- ✓State of health and usage history, restricted to legitimate interested parties
- ✓Disassembly, safety and end-of-life handling instructions
Not yet due — and why
- ○Carbon footprint declaration: for industrial batteries with external storage the timetable is the latest in the Regulation, and the methodology delegated act has not been adopted
- ○Responsible sourcing: methodology not finalised, due diligence postponed to 18 August 2027
- ○Recycled content declaration: due from 18 August 2028
Also worth tracking: supply chain due diligence obligations (Article 48), postponed to 18 August 2027 by Regulation (EU) 2025/1561, with an exemption for companies with a turnover below EUR 40 million.
Where the data comes from in this sector
The hard part of a Battery Pass project is almost never the passport itself: it is knowing who holds each piece of data, how often it changes, and who is entitled to read it. Article 77 and Annex XIII impose tiered access — not every mandatory data point is public.
| Data | Who holds it | Frequency | Access |
|---|---|---|---|
| Module identifiers and bill of materials | System integrator, from cell maker references | At creation | Public |
| Chemistry and critical raw materials | Cell maker | At creation | Interested parties |
| Capacity, power, efficiency, warranted cycles | Integrator testing and performance warranty commitments | At creation | Public |
| State of health and energy throughput | Site EMS, aggregated from rack BMS | Continuous | Interested parties |
| Module replacement and capacity extension | Site operator or maintainer | Per intervention | Interested parties |
| Disassembly and treatment route | Integrator and approved recycler | At creation | Public |
How state of health gets in when the battery is not connected
State of health is the only passport data that has to stay alive after the battery is placed on the market. The market talks about connecting to the BMS as if it were a given — it is not: most batteries in service report nothing continuously. Three routes coexist, and on this segment it is bms connection that is the realistic default.
The BMS reports state of health continuously, through vehicle telematics or site supervision. The finest-grained option, but it assumes connected equipment and a data flow that already exists.
The site EMS already aggregates the rack BMS: the feed exists, it only needs pointing at the relevant passports.
With Arianee — Event-based write API: each reading updates the passport of the battery concerned, with no re-issuance, timestamped and attributed to its source.
Readings are extracted periodically from an existing system — supervision, fleet management, connected chargers, ERP — and loaded in batches. The realistic route when the data exists but is not exposed in real time.
Periodic multi-site consolidation, where each site exposes its data on its own schedule.
With Arianee — Bulk import from the Management Hub or by API: one file or feed updates thousands of passports in a single operation, with a per-line error report.
The technician scans the battery's QR code and enters or confirms the reading on the spot — in the workshop, in store, in the plant room. The only route when the battery is not connected, and the most reliable evidence that an intervention took place.
During maintenance work: module replacement, capacity extension, rack removal — the operation is recorded in the system's passport.
With Arianee — Passport Portal: the scan opens the battery's passport with the technician's rights, and they write their reading and their intervention. Works for a network of third-party workshops without opening the rest of the fleet to them.
The three routes feed the same passport and are not mutually exclusive: a mixed estate usually combines a BMS feed on recent equipment, a batch import for the installed base, and a field reading for anything that comes through the workshop. Every write is timestamped and attributed to its source, which is what makes the history hold up under inspection.
The three hard parts specific to this sector
Deciding the level at which the passport is issued
A container aggregates hundreds of modules. One passport per module is unmanageable; one per container loses the traceability of replacements. The choice has to be made early, consistent with the unit actually placed on the market, and the infrastructure must accept a module–rack–system hierarchy.
The system changes during its life
Modules are replaced, capacity is extended, racks are withdrawn. The passport has to reflect a composition that moves, without full re-issuance at each intervention.
Performance warranty and evidence
Storage contracts rest on residual capacity commitments. The state of health history recorded in the passport becomes a contractual document as much as a regulatory one.
What the passport gives you beyond compliance
A battery passport reduced to an obligation stays a cost. The same data, properly structured, serves operations and the residual value of the fleet.
Evidence of residual capacity
Documenting actual degradation module by module secures warranty commitments and gives an objective basis for end-of-contract disputes.
Taking in second-life batteries
Stationary storage is the natural destination for removed traction packs. A readable passport on the vehicle side determines whether they can be repurposed here, and lets that repurposing be documented.
Multi-site portfolios
An operator running dozens of sites gets, through the passports, a single unified inventory of its module fleet and its condition.
François Pujo
Industrial & Battery Project Manager
François is our Battery Pass expert, working alongside industrial players worldwide to integrate DPP into their production lines and across the entire life of the product.
Frequently asked questions — Energy storage
Is a home storage battery an industrial battery?+
Yes. Regulation (EU) 2023/1542 classifies energy storage batteries as industrial batteries, including where they are installed in a private or domestic environment. A residential battery above 2 kWh is therefore subject to the battery passport from 18 February 2027, with 36 of the 71 data points mandatory.
Does the 2 kWh threshold apply to the module or to the complete system?+
It applies to the battery placed on the market, that is to the unit commercialised as such. This is why the level at which the passport is issued must be settled up front: it determines both whether the obligation bites and the granularity of traceability for the whole life of the system.
What happens when modules inside a container are replaced?+
A replacement module placed on the market after 18 February 2027 is itself covered by the obligation. The system's passport has to reflect its real composition over time: this is a central use case on this segment, and it requires infrastructure able to handle a hierarchy and a composition history, not a fixed document.
Does a vehicle battery repurposed for storage keep its passport?+
Yes. Article 77 provides that the passport ceases to exist once the battery is recycled. A traction battery repurposed for stationary use therefore keeps the passport opened when it was first placed on the market, and the operator reusing it must be able to continue updating it.