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How to check a used Hyundai IONIQ 5 battery before you buy (UK)

Published 2026-10-28 · Last updated 2026-10-28 · based on 12 sourced IONIQ 5 data points and 16 sources

The IONIQ 5 has one of the best battery records in the large test datasets, but it was sold with five battery sizes, the car's own health figure can read 100% when the battery has lost some capacity, and there are two recalls worth checking. This guide covers how to identify the battery, check recalls and the warranty, and compare a test result with thousands of tested cars.

All IONIQ 5 figures with method and date: used IONIQ 5 battery data. Going to a viewing? Make a printable list of questions for the seller.

1. Identify the battery: 58, 72.6, 77.4, 63 or 84 kWh

EV Database listings for the 2WD versions, checked 2026-10-28; usable figures are EV Database estimates. All five are NMC batteries on an 800 V system.

A 2022 "Long Range" car can have either the 72.6 or the 77.4 kWh battery, depending on when it was built. Check the advert, the V5C and the service book, and compare any health figure with the right battery size.

2. Check the recalls: battery module and ICCU

When we downloaded DVSA's recall file on 2026-10-28, it listed six IONIQ 5 recalls (DVSA). Two matter for the battery and charging system:

• R/2026/319 (7 September 2026): a high-voltage battery module may have been made with misaligned electrodes. The fix is to replace the module; until then DVSA's entry says the car can be used as normal but should be parked in a well-ventilated area. It lists 3 UK vehicles built between 28 September 2021 and 7 August 2023.
• R/2024/164 (6 May 2024): the ICCU (integrated charging control unit) may stop charging the 12 V battery, which can put the car into a "failsafe" driving mode. The fix is a software update and a check of the ICCU and its fuse, replacing them if needed. It lists 16,297 UK vehicles built between 13 January 2021 and 29 February 2024, so most pre-facelift cars are included.

Run the free GOV.UK recall check on the registration (GOV.UK). If work was done, ask for the invoice or the dealer's service record.

3. Check the battery warranty

Hyundai UK: 8 years or 100,000 miles for new production models (from 2020); restores at least 70% of original capacity. 5 years / 100,000 miles for taxi/private-hire use. (Hyundai Motor UK, 2024-07 terms, checked 2026-10-20)

• Hyundai's terms say the warranty can be transferred to a new owner while it is still valid, but an invalidated warranty can't be revalidated by selling the car.
• The first UK cars were listed from October 2021, so every private IONIQ 5 is still inside the 8-year limit until about October 2029. Mileage (100,000 miles) is the limit to check.
• Ex-taxi or private-hire cars get only 5 years / 100,000 miles, so one first registered before October 2021 is outside its battery warranty. Ask how the car was used and check the V5C and service history.
• Our battery warranty checker works out the time and mileage left (Private use: 8 years / 100,000 miles, below 70%; Taxi / private-hire use: 5 years / 100,000 miles, below 70%).

4. Don't rely on the car's own health figure

An OBD app can read the car's own battery health (SoH) value, but the published examples show it can read high:

• A UK IONIQ 5 58.2 kWh car at 14,322 miles: the car's own SoH said 100.0%, AVILOO measured 97.7% (Car360, 2026-03-19).
• An owner's IONIQ 5 77.4 kWh at 63,000 km: own calculation of usable energy gave 93.9% of the energy when new, while the car read 98.9% (ioniqforum.com, n=1).
• An owner's IONIQ 5 77.4 kWh at 100,000 km: own calculation of usable energy gave 92.5% of the energy when new, while the car showed 100% (GoingElectric forum, n=1).

These are single cars, but they point the same way: a 100% reading on a car with tens of thousands of miles is not proof of a perfect battery. AVILOO calculates SoH with its own method rather than copying the car's figure (AVILOO GmbH). Prices are on our buying guide, and how to read a battery health certificate explains each field.

5. Compare the result with what's normal

AVILOO medians are the middle value of tested cars at that mileage; the band shows where the central 99% of cars fall. Owner calculations are single cars (n=1) and use different methods. Recurrent figures measure range, not capacity, for US cars. Every row is also on the IONIQ 5 data page.

• In AVILOO's 2026 report the IONIQ 5 had the highest median SoH of all 20 models at 50,000 and 100,000 km. (AVILOO GmbH)
• Even for the best-rated model, AVILOO found the spread between cars grows to over 12 percentage points by 150,000 km. (AVILOO GmbH) At 150,000 km the central 99% of cars ran from 86.7% to 97.8%, so a good model average doesn't guarantee a good car.
• As a 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).
• See how the IONIQ 5 compares with other models on the battery degradation chart, or get a quick estimate with the battery health estimator.

Also see: general used-EV battery checklist · questions to ask an IONIQ 5 seller (printable) · Kia e-Niro battery check · battery problem after buying: your rights (UK) · all models compared.

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.

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