How to check a used EV's battery health
Ask for a battery state of health (SOH) report before you buy any used EV or plug-in hybrid. An independent mobile test costs about $200–$300 and takes minutes; a dealer can also read it with factory tools, and many cars can be checked with a phone app and a $40 plug-in adapter. Most batteries age slowly, but two cars of the same model and age can differ by more than 10%, so test the actual car.
What the numbers mean
- State of health (SOH) is how much energy the battery holds now compared with new. 90% SOH means about 90% of the original range.
- Normal ageing is slow. In battery-tester Aviloo's study of more than 500,000 tests (2022–26), EVs at 150,000 km typically kept about 87–94% of their capacity.
- But cars vary. The same study found up to 13.5% difference between the best and worst examples of the same model, so a single car can be well below average.
- Warranties usually cover the battery for 8 years (Kia 7) and will repair or replace it if capacity falls below a set level, often around 70% (Kia: 75%). Check the exact terms and how many years are left.
- Heat and lots of fast charging wear batteries faster. See what wears out an EV battery.
Independent battery tests in Australia
These plug a small tool into the car's diagnostic port and give a written report with a health score, so they suit a buyer checking someone else's car. They work on most EVs and plug-in hybrids, but not regular hybrids yet.
Prices and areas as published by each provider in 2025–26. Check when you book. We have no commercial link with any of them.
Checking the battery by brand
Tesla
Teslas can test themselves. On software 2025.8.3 or later, go to Controls › Service › Battery Health. The car needs to be at 20% or less and plugged into a home AC charger (5 kW or more), and the test can take up to 18 hours. It can only run once every six months, so ask the seller to run it before you inspect, then show you the result in the car or the Tesla app.
Nissan Leaf
Count the battery capacity bars on the right of the dash: 12 is full health. The first bar goes at roughly 85% health, and each one after that is about 6%. For an exact figure, the LeafSpy Pro app with a Bluetooth OBD2 adapter shows SOH and cell voltages. The Leaf's air-cooled battery wears faster in hot climates, so this check matters most.
Hyundai and Kia
A dealer can print SOH, cell voltages and battery faults with factory tools, and this is the figure that counts for warranty. Apps such as Car Scanner can read SOH through an OBD2 adapter, but Ioniq 5, Ioniq 6 and EV6 often show 100% for years because of a hidden buffer, so also compare usable kWh with the car's spec.
BYD
The BYD app doesn't show battery health. Ask a BYD dealer or a workshop with the right tool for the SOH and any fault codes in writing, or book an independent test.
MG
Some owners read SOH with apps such as Car Scanner or A Better Routeplanner and a Bluetooth adapter, but how the figure is worked out isn't published. For a buying decision, use a dealer printout or an independent test.
Plug-in hybrids
Outlander, Sealion 6 and other plug-ins can usually be tested by the independent services above. Check the electric-only range on a full charge too.
Toyota and Lexus hybrids
Regular hybrids aren't covered by the independent EV tests yet. Ask for the Hybrid Health Check results from Toyota or Lexus servicing: these annual checks are also what keeps the extended hybrid battery warranty going.
Check it yourself
- App and adapter: a Bluetooth OBD2 adapter plugs in under the dash, and an app reads the battery data. Use a quality adapter and unplug it when you're done: some cheap ones are insecure, and some cars set off the alarm if one is left in.
- Range test: charge to 100%, note the range estimate, then compare it with the claimed range for that version. It's rough (weather and driving style change it), but a big shortfall is a red flag.
- Read the dash: look for battery or charging warning lights, and check that fast charging starts and ramps up normally.
Red flags
- SOH well below average for the car's age and kilometres, or a large gap between the highest and lowest cell voltages.
- Battery recalls not done: check the VIN at vehiclerecalls.gov.au. Our used EV guide lists the serious ones.
- A seller who won't allow a battery test.
- Little warranty left and a battery that is already near the warranty threshold.
More on buying used
- Pick my used car: our top three used EVs and hybrids for your budget.
- Used price checker: is the asking price fair?
- Used EV checklist (printable)
- How long EV batteries last
- What a replacement battery costs
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Common questions
How do I check the battery health of a used EV?
Book an independent battery test (about $200–$300 in Australia), ask a dealer for a state of health printout, or use a phone app with a Bluetooth OBD2 adapter. Teslas can run their own Battery Health test from the Service menu.
What is a good battery state of health for a used EV?
It depends on age and kilometres. Large studies show most EVs keep about 87–94% at 150,000 km, so a 3-year-old car with average kilometres would usually be in the mid-90s. Compare the result with the average for that model and age.
Can I check a Nissan Leaf battery without tools?
Yes. Count the capacity bars on the dash: 12 bars is full health. For an exact percentage, use the LeafSpy Pro app with an OBD2 adapter.
Do battery tests work on hybrids?
The independent EV battery tests cover EVs and plug-in hybrids, but not regular hybrids yet. For a Toyota or Lexus hybrid, ask for the Hybrid Health Check results from servicing.
More guides
More in Choosing a car
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How we work it out, and our sources
Weekly cost = the car's energy use × 250 km × your electricity or fuel price, with 90% of charging at home. Prices are list prices at October 2026; check with the dealer.
- Electricity: 2026–27 default rates (AER, Victorian Default Offer, state retailers). Public charging: Sydney network prices, July 2026.
- Petrol and diesel: ACCC capital-city averages, 21 October 2026.
- Cars: maker figures via CarExpert, Drive, CarsGuide and EV Central. Plug-in electric range is taken as 80% of the claim.
- Servicing: published capped prices; marked as an estimate where not yet published (CarExpert comparison).
- Tyres: an EV set lasts about 35,000 km, a petrol or hybrid set 50,000 km (RACV); prices from Gridly.
- Home charger: about $2,000 installed ($1,000–$3,000). Novated leases: PwC summary.
Printed from EV Pick · evpick.com.au. Prices and costs are estimates; check with the dealer. © 2026 EV Pick (T. Crouch). For personal use only; not to be copied, republished or sold without permission.