Last verified: 5 October 2026
What the data actually shows
Real-world fleet data — thousands of high-km EVs — shows degradation is fastest in year one (a few percent), then flattens to roughly 1% per year. The horror stories almost always involve a specific defect, extreme heat without thermal management, or a first-generation Nissan Leaf. Modern liquid-cooled packs are boringly durable.
The checks, in order of importance
- State-of-health report: OBD dongle + model-appropriate app gives a SoH percentage on most Teslas, Hyundais, Kias and MGs. 90%+ is healthy; below 85% needs an explanation.
- Warranty transfer: confirm the 8yr battery warranty transfers to you and check the capacity floor clause.
- Charging history clues: a car that lived on DC fast charging isn't automatically damaged, but ask. Consistent home AC charging is the gentlest life.
- Service records: software updates matter for battery management — a car three updates behind is a yellow flag.
- Physical: underbody scrapes near the pack. Walk away from anything with a battery-case repair history unless discounted hard.
The price logic
Used EV prices fell hard through 2024–25 and have stabilised. The market now prices degradation in crudely: a 4-year-old EV at 88% SoH selling for 55% of new is often the value sweet spot. Cross-check against our new-car pages — when a new MG4 is $33,990 drive-away, a used one needs to be meaningfully cheaper to justify losing warranty years.
Frequently asked questions
Ask for a state-of-health report. Many models expose SoH via an OBD dongle and a free app; some sellers will provide a dealer battery report. Budget $50 for your own dongle if you're shopping seriously — it pays for itself on the first car you walk away from.
Typically 10–15% of original capacity by 150,000km, then degradation flattens. A car that did 450km new does roughly 390km at that mileage — annoying, rarely decisive. Below 80% is where warranty claims begin (70% is the common floor).
On virtually all brands sold in Australia, yes — the 8-year/160,000km battery warranty follows the car. Confirm in writing with the manufacturer before purchase; some warranties have servicing-history conditions.
Not automatically. EV drivetrains have fewer wear parts than petrol cars, and high-km examples with good SoH reports are often bargains. The real risks are rideshare history without disclosure and cars that lived on DC fast charging in extreme heat.