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EV Evidence

Used EV evidence · UK

The boundary of Lam's calendar-ageing study

The Lam study is laboratory calendar-ageing evidence rather than an in-use EV fleet study. It tracks relative capacity and relative resistance during diagnostic cycles while excluding cycling duty, charging rate and vehicle-level controls. Use it to understand those laboratory metrics, not to predict an individual UK vehicle's battery outcome.

Joule: A decade of insights: Delving into calendar aging trends and implications

Reviewed

Key facts and evidence

For a UK battery decision, as of 13 August 2026, Lam's 2024 publication provides laboratory calendar-ageing evidence with separate relative-capacity and relative-resistance metrics. Its admitted E2 record does not include cycling duty, charging rate, pack controls, vehicle range or field replacement. It therefore cannot supply a complete in-vehicle prognosis.

Joule: A decade of insights: Delving into calendar aging trends and implications

Lam's laboratory calendar-ageing evidence separates capacity and resistance trends but does not represent complete vehicle operation.

Inside the study boundary

The E2 record defines Q(t) relative to Q(0) and R(t) relative to R(0), measured during periodic diagnostic cycles. This supports careful discussion of laboratory capacity and resistance metrics.

Outside the boundary

The metric record explicitly excludes cycling duty, charging rate, pack controls, vehicle range and field replacement. Those omissions prevent a direct translation from the laboratory study to the complete history or future of a used EV.

Source and date

Lam and colleagues published the article online on 18 December 2024 under CC BY 4.0. E2 retrieved it on 12 August 2026 and checked the current evidence build on 13 August 2026.

Next step

Use the study only for the definitions and limits it actually reports. For an individual UK vehicle, follow E3 row e3-s11-008 and request a report that identifies the vehicle, method, test conditions, reference and limitations.

What to do next

Laboratory calendar-ageing evidence does not determine whether an individual vehicle should be driven.

Immediate action: Separate laboratory ageing evidence from vehicle-specific operating evidence.

  • Do not use the study as an individual prediction when vehicle duty, pack controls and measurement context are not represented.

Checks that stay with this vehicle

  1. Compare the report's vehicle, duty, method and conditions with the Lam study's laboratory calendar-ageing scope and exclusions.

    Only the study's stated metric definitions and laboratory boundary inform the document review.

    Obtain vehicle-specific professional evidence if the decision requires in-use behaviour absent from the study.

Professional hand-off

  • Ask an EV-competent battery specialist to explain how a vehicle-specific result differs from laboratory calendar-ageing evidence.

Questions this record can answer

What does the sourced evidence say about inside the study boundary?

The E2 record defines Q(t) relative to Q(0) and R(t) relative to R(0), measured during periodic diagnostic cycles. This supports careful discussion of laboratory capacity and resistance metrics.

What does the sourced evidence say about outside the boundary?

The metric record explicitly excludes cycling duty, charging rate, pack controls, vehicle range and field replacement. Those omissions prevent a direct translation from the laboratory study to the complete history or future of a used EV.

What does the sourced evidence say about source and date?

Lam and colleagues published the article online on 18 December 2024 under CC BY 4.0. E2 retrieved it on 12 August 2026 and checked the current evidence build on 13 August 2026.

Sources