The EV Battery Passport

Of all the passports created by EU law so far, the electric vehicle battery passport asks for the most. It is the only one requiring data that changes continuously across a service life measured in years, maintained by parties who change during that life.

What the record has to carry

Regulation (EU) 2023/1542 sets out the content, and it divides into three kinds of data with very different characteristics.

The third row is what makes this passport structurally different from every other. A textile passport is a declaration made once; an EV battery passport is a record that must remain accurate while the battery is being used by somebody the manufacturer has no relationship with.

The custody problem

A battery passes through several hands, and the question of who is responsible for keeping the record current at each stage is not simple.

The fifth step is where most designs struggle. A second or third owner has no contractual relationship with the vehicle manufacturer, may service the vehicle independently, and has no obligation to feed data anywhere.

Where cell-level data comes from

Several required attributes concern the cell rather than the pack, and cells are typically manufactured by a small number of specialised suppliers, frequently outside the EU.

Carbon footprint of cell production, recycled content of active materials, and due diligence on cobalt, lithium, nickel and graphite all originate there. A vehicle manufacturer cannot produce any of them from its own operations.

• Cell production footprint — dominated by the energy mix of the cell plant, which the buyer does not control.
• Active material recycled content — traceable only through the cathode supply chain.
• Due diligence evidence — mine to refinery, several tiers beyond the cell maker.
• Chemistry detail — commercially sensitive, and a genuine negotiation.

The last point is a real tension rather than an obstacle to be engineered away. Cell chemistry is competitively valuable, and the permissioned access model exists precisely so that a recycler can learn what they need without the information becoming public.

State of health decides the money

Almost every commercially significant decision about an EV battery turns on state of health: residual vehicle value, warranty exposure, whether second life is viable, and what a recycler will pay.

It is also the attribute with the least methodological agreement. State of health is usually expressed as remaining capacity against original, and how that is measured — under what conditions, at what temperature, over what discharge — varies between manufacturers enough that figures are not directly comparable.

This matters for the passport because a declared figure invites comparison. Two batteries showing the same number may have been assessed differently, and without the method stated alongside it the number is less informative than it appears.

Second life is the intended destination

The regulation anticipates that EV batteries will be repurposed rather than recycled at the end of vehicle life, and the passport is the mechanism intended to make that practical.

A repurposer receiving a pack with capacity history, fault records and cycle count can grade it in minutes. The same pack arriving as an anonymous used assembly must be tested from scratch, and the testing cost frequently exceeds what the pack is worth.

Repurposing also makes the repurposer an economic operator with their own obligations, which means the passport has to support a new record referencing the original rather than simply continuing it.

What manufacturers should be doing

Two things have long enough lead times to be started well before the obligation applies.

Secure cell-level data contractually, because it originates outside the organisation and cannot be produced internally at any price. And design the in-service data path around vehicles that have left the dealer network, because that is the case the requirement actually turns on and the one that a pilot with fleet vehicles will not reveal.