There is no letter. No dashboard warning, no email from the manufacturer, no reminder at your last service. The battery warranty on your electric or hybrid car simply runs out one day, and the first you hear of it is when you need it and it is gone.
That is a strange thing about the single most expensive component in the car.
The deadline is closer than most owners think
Every battery warranty in Australia is a race between two clocks — years and kilometres — and whichever finishes first ends the cover.
For most private owners the time limit arrives first. But for anyone doing more than about 20,000 km a year, the distance limit gets there sooner, and the difference can be years. Some examples of how tight it actually is:
Mini's electric models are capped at 100,000 km — the lowest of any brand we track, and 60,000 km below parent company BMW. At 18,000 km a year that runs out around year six, well before the 8-year term.
Kia's pre-2027 cars stop at 150,000 km, which is genuinely reachable on a commuter car.
BMW plug-in hybrids get 6 years or 100,000 km — two years and 60,000 km less than BMW's electric cars.
GWM gives private owners unlimited kilometres, so time is the only limit. It is the exception.
Five brands guarantee nothing at all
This is the part owners find hardest to believe. Of the sixteen manufacturers we hold verified Australian terms for, five publish no minimum capacity percentage whatsoever:
Hyundai, BMW, Mini, Mercedes-Benz and MG.
Their warranties cover defects — something failing. They make no published commitment about capacity. If your car's pack quietly fades to 72% over six years, that is not a defect and there is no claim, because nothing has failed.
BMW and Mini go further and cover "excessive capacity loss" without ever defining excessive. Nissan measures its guarantee in bars on the dashboard gauge rather than a percentage. Volvo's own two pages contradict each other on whether 70% is guaranteed. Toyota and Lexus exclude degradation from hybrid battery cover entirely.
Against that, Volkswagen and Cupra publish a stepped curve — 78% at three years, 74% at five, 70% at eight — which is the most specific guarantee anybody offers in this market and lets you check a car against the manufacturer's own expectation years early.
See where your car sits: battery warranty terms by brand.
Why testing before the deadline is worth real money
If your battery is below the threshold and still in warranty, the manufacturer repairs or replaces it. That is a component worth many thousands of dollars — and on some models more than the car.
If you find out after the deadline, it is yours.
The gap between those two outcomes is often a few months, and the only thing standing between them is knowing. A dated, independent measurement taken while the cover is live is what turns "the range seems worse lately" into a documented position.
How a degradation claim actually works
1. Establish where you stand. Get a dated, independent measurement with the vehicle identified. Do this before you contact anyone.
2. Check the terms for your exact car. Years, kilometres, the capacity floor if one is published, and whether the in-service date starts the clock. Model year matters — Kia steps up at MY2027, Tesla splits its distance limit by variant.
3. Approach the manufacturer or dealer with evidence, not an impression. They will run their own diagnostics, and they should. But arriving with a written third-party result changes the conversation from a complaint into a documented case, and it means there is a record that predates their assessment.
4. If the terms are ambiguous, get their position in writing. Particularly with Volvo, where two official pages disagree, and with MG for cars retailed before August 2024, where MG's own pages give different kilometre limits.
5. Keep everything dated. Warranty disputes turn on timing.
We should be clear about our own role: we provide evidence. We are not a party to any claim, we do not negotiate with manufacturers on your behalf, and we have no relationship with any of them.
When to test
Six to twelve months before either limit — enough time to act on what you find
Before selling, because a documented healthy battery is worth more than an undocumented one
Before buying used, because you inherit whatever is left of the cover and nothing more
If range has dropped noticeably, rather than waiting to see whether it gets worse
Check your warranty terms and remaining cover · Book a test — $249
Warranty terms verified 13 September 2026 from each manufacturer's own Australian documents, with sources listed on the individual brand pages. Manufacturer terms change, and the terms that apply to any given car are those in force when it was first sold.