An EV battery retired at 75% capacity can still earn a decade in stationary storage - or it can be scrap. The difference is rarely the battery; it is whether anyone can prove its condition. Live BMS data in the passport makes that proof routine.
The battery passport is discussed as an EV rule, but every industrial battery above 2 kWh placed on the EU market from 18 February 2027 needs one, and that threshold covers essentially all stationary storage. Systems ordered today will be delivered under the new regime, so passport readiness belongs in the purchase order, not in a compliance file opened after commissioning.
The first mass generation of EV batteries retires between 2027 and 2035, and the recovery targets waiting for those packs are already law: 50% of lithium by end 2027, 80% by 2031, 95% for cobalt, copper, lead and nickel. Europe is building shredding capacity on schedule. The scarce resource is the paperwork that turns a retired pack into countable, recoverable kilograms.
Two physically identical retired EV packs can differ in price by about 30%. The gap is not the cells, it is proof: buyers discount undocumented packs, cycle-test them for weeks, and struggle to warranty or finance the result. A worked second-life storage example shows where each euro of the premium comes from.
The EU battery passport must carry state-of-health and usage data that stays current through the battery's life, per Annex VII of Regulation 2023/1542. The BMS already measures everything the annex asks for; the missing piece is the bridge that carries those numbers into the passport across every change of owner, because live SoH is the input the reuse-or-recycle decision runs on.