How battery testing actually works

The main test types

• Manufacturer / dashboard readout

  The car's own Battery Management System (BMS) estimate, shown on the dashboard or an app (e.g. Tesla's Controls → Service → Battery Health). It requires no extra equipment, but it's built for day-to-day range estimation, not a precise, independently verifiable health figure — and on most cars, only the current owner can access it.

• Fast OBD-based test (e.g. AVILOO FLASH, Moba Certify Pro)

  A technician plugs a diagnostic box into the car's OBD-II port for a few minutes while the car is stationary. It reads deeper Battery Management System data than the dashboard shows and compares it against a large statistical model of similar vehicles, rather than needing a full charge/discharge cycle. This is the type of test most independent buyer/seller checks — including ours — use.

• Full charge/discharge test (e.g. AVILOO PREMIUM)

  The most direct measurement: an actual discharge cycle drive gives a real capacity reading rather than a statistical estimate, taking a few hours rather than a few minutes. It's aimed at a buyer who wants the strongest possible proof before committing to a specific car — the usual pattern is screening several cars with a fast test first, then getting this done on the one you're serious about.

• Laboratory / cell-level testing

  The most thorough option — measuring individual cells directly, sometimes with the battery removed — used for research, warranty disputes, and remanufacturing rather than a routine pre-purchase check, given the cost and time involved.

Our EV Buyer Check uses an independent OBD-based test — the same category most trade and consumer battery certificates in Ireland use — not a manufacturer dashboard reading.

Manufacturer/owner test vs. independent test

A manufacturer's own battery health figure isn't necessarily wrong — but it answers a different question than an independent test does, for a few concrete reasons:

• Who can commission it matters most in practice: a manufacturer's own reading (like Tesla's built-in Battery Health check) needs the current owner's account access and cooperation to run — a buyer can't independently order it before handing over money, and can't verify a seller didn't run it and quietly not share a bad result. An independent test can be commissioned by whoever pays for it, including a buyer inspecting someone else's car.
• A manufacturer's BMS is also built to manage day-to-day charging and range prediction, not to produce a precise, standardised health percentage — AVILOO's own CEO has described these systems as lacking "the computing power or the inherent methodology" to calculate state of health accurately (Forbes, July 2026).
• Most EVs are driven and charged between roughly 20-80%, so the BMS rarely sees a genuine full cycle to base a reading on — and there's no visible timestamp showing how stale a dashboard figure is.
• There's no standardised methodology across manufacturers, so a reading from one brand's BMS isn't necessarily comparable to another's — independent testers exist partly to make results comparable across makes and models.

Who runs battery certification

Most independent battery tests trace back to one of a small number of accredited providers under CARA (Car Remarketing Association Europe), the industry body that accredits battery-testing methodologies. The company you deal with directly is often a reseller of one of these — Ireland's existing battery-check services (see Resources) license technology from providers on this list rather than running their own accredited methodology.

• AVILOO

  Austria, sold across Europe (incl. Ireland) and the UK

  The largest independent player by test volume (500,000+ tests). CARA-approved for its FLASH (fast screening, ~20-30 min) and PREMIUM (full-cycle, ~2-4 hours, for a buyer wanting documented proof on one specific car) tests, with a financially backed battery warranty now offered in 24 European countries. Selected as preferred trade-in/remarketing test by Mercedes-Benz, Volvo, and Porsche Holding, and used by leasing groups Ayvens and Arval and auction houses BCA and Cox. In Ireland, sold trade-only via National Vehicle Distribution (NVD); MotorCheck resells it too, but only in the UK and Northern Ireland, not the Republic.

• EV Drivetrain Solutions

  Ireland (Mullingar, Co. Westmeath)

  The closest direct-to-consumer AVILOO reseller we've found in the Republic — books private buyers, sellers, and independent dealers straight, not through a dealer intermediary. €100 flat for a standard customer check; call-outs and dealer/trade pricing available on request.

• Moba (Certify Pro)

  Netherlands, sold in Ireland via BatteryChecked.ie

  CARA-approved. The technology behind BatteryChecked.ie's SoH certificates, positioned mainly at helping sellers and dealers demonstrate battery condition.

• CARVOLT

  Netherlands, operates across Europe

  OBD-based test supporting 55+ brands, ~5 minutes per certificate, priced around €30 retail. Also sells a DIY diagnostic kit to workshops that want to run their own tests rather than outsource.

• CertifyCar

  Germany, also operating in Austria, Spain, and Portugal

  Runs a TÜV Nord-standard SoH check via a diagnostic connector sent to the vehicle, with results typically back within 24 hours — offered alongside broader used-car appraisal reports, not just the battery.

• TÜV NORD, TÜV SÜD, DEKRA

  Germany-headquartered, operate across Europe

  Established vehicle-testing/certification bodies (the kind that run roadworthiness inspections) that have each launched their own CARA-approved EV battery health check.

• MAHLE, Autel, LAUNCH

  Global automotive diagnostics manufacturers

  Better known for garage diagnostic equipment generally; each has a CARA-approved battery-health function built into their existing tools, mostly sold to workshops and dealers rather than directly to consumers.

• Recurrent

  United States

  Takes a different approach — a predictive report from real-world fleet telematics data rather than an on-site physical test, positioned as "a CarFax for EV batteries." Partnered with Experian/AutoCheck to bundle in vehicle history.

• EV All Day

  United Kingdom

  An instant, low-cost (£9.99) report generated from a registration number and mileage — data-driven rather than a physical test, aimed at screening listings before a viewing.

• VAM Checks

  Ireland (Dublin-based, travels nationwide)

  The closest Ireland-based comparison to this check: a 130+ point full vehicle inspection with an OBD battery/hybrid-system diagnostic bundled in, priced at €314 for an EV/hybrid, with a stated focus on Japanese imports. Bundles far more of the car (bodywork, suspension, brakes, road test) than a battery-only test, at a mechanic-inspection price point rather than a quick OBD read.

What a more mature EV market looks like

Norway is 5-10 years ahead of Ireland on EV adoption (new car sales there are now almost entirely electric), so its used-EV market shows roughly where Ireland's is heading. Norsk Elbilforening (the Norwegian EV owners' association) partnered with AVILOO and Viking (a roadside-assistance and inspection network) to put certified battery testing into physical inspection stations nationwide, rather than running it concierge-style — the same fast/thorough split we offer: a quick, walk-in "Flash" test for screening a car or getting a fast answer, and a longer "Premium" test for a buyer who wants the strongest possible proof on the specific car they're about to commit to, before committing. Ours is currently the concierge model — we book the test and coordinate everything by hand while we validate demand — but it's the same underlying idea: certified, independent testing, not a dashboard number.