The seventh-generation ES 300h was launched with a nickel-metal-hydride hybrid battery and moved to a lithium-ion pack at its mid-life facelift. Same body, same badge, two different batteries with two different repair stories. Before you price a used ES 300h, find out which one is in it.
Why the split matters
The NiMH cars sit inside the ecosystem that makes older Toyota and Lexus hybrids cheap to keep alive: module-level repair, exchange packs, aftermarket suppliers. A weak NiMH pack in an early ES 300h is a known, bounded problem.
The lithium cars are lighter and newer, but those cheap routes are thinner. If a lithium pack ever needs attention, expect a Lexus part at a Lexus price. This is the same counterintuitive pattern as the Corolla and Camry: the older car often has the better repair economics.
The exact model year of the switch differs between markets, and Australian facelift timing does not line up neatly with the American one you will read about in forums. A measurement resolves it — the pack identifies itself.
Lexus's warranty
5 years, unlimited kilometres, extendable to 10 through an annual Lexus traction battery health check. Capacity degradation is excluded. Transferability is not stated. The earliest seventh-generation cars are now well past five years, so on a used one the dealer health-check history is the warranty — and a missed year ended it. Full detail: Lexus battery warranty in Australia.
What's normal
The ES is a large, quiet sedan that tends to be owned by people who service it on time and drive it gently. A NiMH car from 2019 with 100,000 km should be unremarkable; the usual trigger on these packs is a few weak modules rather than uniform decline, and it shows first as a charge gauge that swings quickly.
What actually fails
Individual modules on NiMH cars; cell-group imbalance on lithium. Then the cooling path — the intake collects dust and lint, the pack runs warm, cells age unevenly. Then, rarely, the battery ECU.
On the test drive
Engine off at rest, electric creep in a car park, charge gauge steady, no constant fan noise from behind the rear seat, fuel figure close to Lexus's claim.
What to check before you buy
Which pack the car has, which sets the repair economics
Module or cell-group voltage spread
Cooling intake condition
Stored and pending hybrid fault codes
Lexus health-check history if extended cover is being claimed
Lexus NX 350h · Toyota Camry Hybrid · Book a test — $249
Chemistry change at the facelift as reported by Green Car Reports; Australian timing not independently confirmed, hence the advice to identify the pack on the car. Warranty terms from Lexus Australia. Verified 15 September 2026.