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EV battery health check in the UK: test options and prices compared
Published · Last updated · prices checked 2026-10-30
Buying or selling a used electric car in the UK? This guide compares the ways to check its battery health, from free readouts on the car to £49 post-out kits and £95–£100 mobile tests. It covers what each one actually measures, what it costs and which one fits your situation.
UK battery test options compared
| Option | How it works | Where the SoH comes from | Price (checked 2026-10-30) | Best for |
|---|---|---|---|---|
| Car's own display or app | Look in the car's menus or app. Some models show a battery health or capacity figure; most only show a range estimate | The car's own estimate. Some makers release reserve capacity as the battery ages, so the range readout can look stable (Recurrent) | Free | A quick first look at a viewing |
| Tesla in-car Battery Health test | Controls › Service › Battery Health. The optional test needs an AC charger, runs the battery below 10% and takes up to 24 hours (Tesla UK) | The car's battery management system (BMS) | Free | Owners and sellers with time. Since software 2025.26 the test has been removed or made read-only on many cars (Not a Tesla App). See our Model 3 and Model Y guides |
| OBD app + Bluetooth adapter | Apps such as LeafSpy (Nissan Leaf) or Car Scanner read battery values through the OBD socket (LeafSpy, MGEVs.com owner forum) | The car's BMS; what is shown, and how reliable it is, varies by make and app | Cost of an adapter and app | Enthusiasts; Leaf buyers (see our Leaf guide) |
| Post-out test kit (EV Battery Checker) | A kit is posted to you; you plug it into the OBD socket and post it back. Uses Moba technology; CARA approved (EV Battery Checker) | Moba certificates show the SoH as calculated by the manufacturer (BMS) (Moba) | £49 per test, UK & Ireland, return postage included (EV Battery Checker) | Owners selling privately; buyers who can get the kit to the car |
| Mobile AVILOO FLASH test | A tester comes to the car and runs a short OBD test (about 3 minutes test time) (Battery Health Check); certificate with benchmark, range estimates and QR verification (Battery Health Check) | AVILOO's own calculation, stated within ±3% in at least 95% of reference measurements (AVILOO GmbH) | £100 paid on the day via Battery Health Check (Battery Health Check); local examples: £95 flat in Pontypridd (Pontypridd Automotive Diagnostics), from £99 around Watford (Dual Action Roadside) | Buyers who want an independent figure; qualifying UK tests since 1 July 2026 include a £2,700, 12-month AVILOO battery warranty (Battery Health Check). It doesn't transfer under lease or hire purchase (AVILOO GmbH), and one tester says it covers private use only (Pontypridd Automotive Diagnostics). Check model coverage (AVILOO GmbH) |
| Generational certificate | OBD dongle + app, about 2 minutes (Generational). Sold to dealers; private buyers get it through a dealer or an independent mobile tester (Generational) | The car's BMS value; Generational says it matches an official manufacturer diagnostic tool (Generational) | Dealers from £29 per car (Generational); e.g. a Halifax mobile tester charges £90 plus call-out (EVBatteryHealthChecker.co.uk) | Dealer stock (ask the dealer for it); also shows cell voltage balance (Generational) |
| AA pre-purchase inspection (EV versions) | A whole-car inspection. Comprehensive EV and Advanced EV include 5 EV checks: hybrid/electric battery test, charge port, inverter coolant, 240v charging and charge lead (The AA) | Not stated on the AA's checklist – ask whether you get an SoH % or certificate | Comprehensive from £199, Advanced from £279; AA members 10% off. Not available in Northern Ireland, parts of Scotland and Wales, or the islands (The AA) | Buyers who want the whole car inspected, not only the battery |
| Manufacturer approved-used check | Some approved-used programmes include a battery check: VW Approved Used electric cars come with a battery health certificate (Volkswagen UK); pre-owned Polestar 2s get a battery SoH test, with results given before purchase (Polestar UK) | Varies by brand – ask which tool was used | Included in the car's price | Franchise-dealer buyers: ask for the report before you pay a deposit |
SoH = state of health: usable battery capacity now as a percentage of new (glossary). BMS = the car's battery management system (glossary). We are not paid by the battery-test providers mentioned on this page. Links marked "paid link" in the "Useful products and services" box are affiliate links. See our disclosure.
Which test fits your situation?
- Buying from a dealer: ask for an existing certificate first. If there is one, check that the VIN, date and mileage match and that it can be verified online. Our guide to reading a battery certificate explains each field.
- Buying privately: a mobile AVILOO test (about £95–£100) can be done at the seller's address with their permission. A post-out kit (£49) works if the seller will run it, or if you can wait for the kit to arrive.
- Selling your EV: a recent certificate answers the buyer's first question. See how to prove battery health when you sell.
- High-mileage car or out of warranty: a test matters most here. Most UK battery warranties end at 100,000 miles; see buying a high-mileage EV and the battery warranty checker.
- Want the whole car checked: an inspection such as the AA's EV tiers covers more than the battery, but confirm what battery result you get.
Independent figure or the car's own figure?
The biggest difference between tests is who works out the SoH. AVILOO calculates it with its own algorithm from vehicle data rather than copying the car's reading (AVILOO GmbH). Generational and Moba-based tests report the figure the car's BMS calculates (Generational, Moba). Neither is "wrong", but the two can differ by a few points, so compare like with like. Treat differences of 1–3 points as noise. More in battery state of health explained.
Whichever test you use, also ask about cell voltage balance: in about 10,000 UK used-EV tests, roughly 1 in 85 cars showed an imbalance above 50 mV worth investigating (Generational).
Got a result? Is it good?
Compare it with data for the same model at a similar mileage, not a general figure. Cars of the same model at similar mileage can differ by up to 13.5 points (AVILOO GmbH). Use the battery health estimator, your model's page in all models, or plot it on the battery degradation chart. As a broad rule of thumb for all EVs, ADAC expects at least 92% at 50,000 km, 88% at 100,000 km, 84% at 150,000 km, 80% at 200,000 km (ADAC).
Next steps: full used-EV battery checklist · questions to ask the seller · reading a battery certificate · battery replacement cost (UK) · battery problem after buying: your rights (UK)
Sources used on this page
26 sources.
- Large test datasets (2 sources): Generational, AVILOO GmbH
- Connected-car / telematics (1 source): Recurrent
- Owner-reported (1 source): MGEVs.com owner forum
- Manufacturer (3 sources): Tesla UK, Volkswagen UK, Polestar UK
- Other (specs, guides, news, surveys) (19 sources): EV Battery Checker, Moba, [2], Battery Health Check, Pontypridd Automotive Diagnostics, Dual Action Roadside, [2], AVILOO GmbH, [2], [3], [3], Generational, [2], EVBatteryHealthChecker.co.uk, The AA, [2], Not a Tesla App, LeafSpy, ADAC
Owner-reported and listing values are single cars (n=1) read from the car, an app or an OBD tool – useful examples, not averages. Range-retention figures (Recurrent) measure range, not capacity. Full details: methodology & all sources.
Get this specific car tested
We are not paid by these test providers. How we make money.
Model averages can't tell you about the car in front of you. An independent battery test (typically a short OBD plug-in test, some remote) gives an SoH figure and often a certificate you can use when negotiating.
- AVILOO – Independent OBD-based battery test (FLASH / Premium) with certificate; available via partners in the UK and EU.
- Generational – UK OBD plug-in test with certificate (SoH, range, remaining warranty, cell balance); sold through dealers and independent mobile testers.
- Moba – Postal OBD kit: you run the test yourself and post the box back for a digital battery certificate (Europe – check vehicle support and delivery country).
Prices change – check the provider's site. Provider names are used for identification only. Compare all UK options and prices: EV battery health check UK.
Useful products and services
- Charging cable: check that the car comes with its charging cable(s) at the viewing. If one is missing, replacements are sold separately: Type 2 charging cables at EV King paid link.
- Tyres: check tread depth and wear at the viewing. To price replacements, search by the size printed on the tyre wall: car tyres at Tyres UK paid link.
- Leasing instead of buying used (UK): if you'd rather not take on an older battery, you can compare electric car lease deals: EV lease deals at Leasing.com paid link.
- Parts and tools: wiper blades, bulbs, 12V batteries and tools for the car you buy: GSF Car Parts paid link (UK).
Some links are paid links: we may earn a small commission at no extra cost to you. This never changes the battery data we show (disclosure).
FAQ
How much does an EV battery health check cost in the UK?
Prices we found on 2026-10-30: a post-out kit you plug in yourself costs £49 (EV Battery Checker, Moba-based, return postage included). A mobile AVILOO test costs about £95–£100 (Battery Health Check £100 paid on the day; local testers £95 in Pontypridd and from £99 around Watford). Generational tests are sold to dealers from £29 per car; one Halifax mobile tester charges £90 plus call-out. The car's own display and the AA's EV inspections are other options. Prices change, so check with the provider.
Which EV battery test is the most accurate?
There is no single answer, because tests measure different things. AVILOO calculates state of health (SoH) with its own algorithm and says it is within ±3% in at least 95% of reference measurements. Generational and Moba report the SoH calculated by the car’s own battery management system (BMS), which Generational says matches an official manufacturer diagnostic tool. Compare a result with data for the same model, and compare like with like.
Can I test an EV battery myself?
Partly. Some cars show a battery health figure in a menu or app, Tesla has an in-car test on some cars, and OBD apps such as LeafSpy (Nissan Leaf) read the car’s own values with a Bluetooth adapter. A post-out kit (£49 when we checked) gives you a certificate without a technician. For a car you are about to buy, a certificate the seller can’t edit is stronger evidence.
Does an AA inspection include a battery health check?
The AA lists a hybrid/electric battery test among 5 EV checks in its Comprehensive EV and Advanced EV inspections (from £199 and £279 when we checked on 2026-10-30). Its checklist doesn’t say whether you get a state-of-health percentage or a battery certificate, so ask before booking if that is what you need.
Who pays for the battery test when buying a used EV?
There is no fixed rule. Some dealers already have a certificate, so ask for it first. In a private sale the buyer usually arranges and pays for the test, with the seller’s permission; a recent certificate from the seller saves you the cost but check it is genuine and recent.
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