The NX 450h+ is Lexus's plug-in hybrid SUV, with an 18.1 kWh battery and a claimed electric range of 87 km on the NEDC cycle — an older, optimistic test standard that typically runs 20–30% above what a WLTP figure would show. Treat the real-world electric range as meaningfully lower than 87 km.
The warranty position
Lexus covers hybrid, plug-in hybrid and EV traction batteries for 5 years with unlimited kilometres, extendable to 10 years, subject to an annual Traction Battery Health Check after the fifth year. Capacity degradation is not covered.
The 70% capacity floor Lexus publishes applies to the RZ, its battery-electric model. It does not apply here.
Lexus also does not publish a transferability statement, so we have marked that unavailable rather than assume it. And Lexus's own terms state that "measurement methods and replacement decisions rest solely with Lexus Australia" — worth knowing before you rely on a claim.
Full detail: Lexus battery warranty in Australia.
Why a plug-in pack needs more attention than a hybrid one
A plug-in hybrid battery gets cycled deeply and often. An owner who plugs in nightly is doing something close to a full charge-discharge cycle most days — which is what ages a battery fastest, and is a far heavier duty than a conventional hybrid's shallow, narrow-window operation.
Replacement economics are also different. Australia's cheap module-repair and reconditioning industry was built around nickel-metal-hydride packs in Toyotas and Lexuses. It does not extend to plug-in hybrid lithium packs, and we could not find any published Australian replacement price for this model.
For context on what plug-in replacement can cost in this market, Mitsubishi Australia quotes $15,000–$16,000 for a 2022-on Outlander PHEV pack. We are not suggesting the Lexus figure is the same — we do not know it — but it indicates the order of magnitude a plug-in pack sits in, which is not the order of magnitude a Camry Hybrid sits in.
Ask how it was used
The single most useful question on a used NX 450h+ is how often it was actually plugged in.
Plugged in nightly: the pack has done a lot of deep cycles for its age, and the car has been used as intended.
Rarely plugged in: fewer cycles, but the car has spent its life hauling a large battery it never used, running as a heavy and relatively thirsty conventional hybrid. That is a legitimate reason to ask why you would buy a PHEV at all rather than a hybrid.
Neither answer disqualifies the car. Both should change what you pay.
What to check before you buy
How often it was charged, and whether there is any charging history
Measured condition of the pack and module or block voltage spread
Whether annual Traction Battery Health Checks were done, if extended cover is being claimed
Lexus's position in writing on what is covered for that specific vehicle
Stored and pending fault codes
Battery capacity and NEDC electric range from Lexus Australia. Warranty terms from Lexus Australia's warranty page. Mitsubishi comparison figure via Drive, September 2024. Verified 13 September 2026.