A battery-condition metric describing current capability relative to its original or rated condition, usually used for lifecycle, warranty, and second-life decisions.
State of health turns battery degradation into a decision-making signal. It supports service, warranty, resale, repurposing, and end-of-life workflows only when the calculation method and threshold behind the value are clear.
EU Battery Regulation context makes state-of-health relevant to performance and information flows, but the value is not self-explanatory. Different chemistries, BMS methods, test procedures, and baselines can produce values that look comparable but are not.
Regulation (EU) 2023/1542 concerning batteries and waste batteries
a measure of the general condition of a rechargeable battery and its ability to deliver the specified performance compared with its initial condition;
Reference: Article 3, point 28
Reviewed public draft page. Aligns with high-priority battery section-role policy: plain working definition, concise source boundary, concrete implementation objects, and evidence-focused commentary.
Implementation records should capture state-of-health value, measurement method, timestamp, baseline, rated capacity reference, data source, validation status, decision threshold, actor, and related service or second-life decision. A bare percentage is not enough evidence.
State-of-health evidence must be linked to method, time, and decision context. Without those controls, a passport can display a precise-looking value that is not reliable for warranty, resale, repair, or repurposing decisions.