Original power capability: the same quantity in two places in the passport

Two tiers, two levels of access

Point 1 of Annex XIII is public and relates to the model. Point 4(a) requires the values for the performance and durability parameters referred to in Article 10(1), when the battery is placed on the market and when its status changes, accessible only to persons with a legitimate interest. Point 3 reserves the results of test reports to notified bodies, market surveillance authorities and the Commission. One measurement therefore feeds three separate entries with three different readerships — and only the first is public.

What Annex IV counts as power

Annex IV defines power as the amount of energy a battery is capable of providing over a given period under reference conditions. That is not the catalogue peak figure, which is often quoted for a few seconds. Point 2 of Part A of Annex IV requires power in watts together with power fade in per cent, and Part B requires the ratio between nominal battery power and battery energy. Without the period and the reference conditions, the value cannot be verified.

“Limits” has substance in the Regulation

Point 1(i) requires limits alongside the value. Part B of Annex IV shows what that means in practice: power capability at 80% and 20% state of charge. Power on a nearly empty battery is materially lower than on a full one, and that difference is precisely what a buyer needs. Enter a single number and you have answered half the question.

If the Article 10(1) document exists, you already have the value

Since 18 August 2024, Article 10(1) requires rechargeable industrial batteries above 2 kWh, LMT batteries and electric vehicle batteries to be accompanied by a document containing values for the parameters in Part A of Annex IV. Power and power fade are among them. The technical documentation under Annex VIII must in addition explain the technical specifications, standards and conditions used to measure, calculate or estimate them. If that document does not exist, you have an older problem than the passport.

The cell catalogue does not help here

Pack power is not the sum of cell power: conductors, joints, the fuse, contactors and cooling all constrain it. A cell supplier can issue a cell value under their own conditions, but not the original power capability of the battery placed on the market. This field therefore normally requires a pack-level measurement — at the pack manufacturer or the laboratory that performed it.

Where it goes wrong

• A catalogue peak power from the cell instead of power under the Annex IV reference conditions.
• A single value with no limits — Part B of Annex IV also expects power capability at 80% and 20% state of charge.
• Publishing an individual-battery value that belongs to the restricted tier under point 4(a) of Annex XIII.
• Publishing an extract of the test report in the public section; under point 3 of Annex XIII report results are reserved to authorities.
• Preparing this field when the Article 10(1) document, mandatory since 18 August 2024, has never been drawn up.

Frequently asked