The current NX 350h uses a lithium-ion hybrid battery, and Lexus covers it for 5 years with unlimited kilometres, extendable to 10 years through an annual traction battery health check — with capacity degradation excluded. The 70% capacity floor Lexus publishes applies only to the RZ, its electric car. It does not apply here.

What the chemistry means

The second-generation NX (from 2022) moved to a lithium-ion pack — lighter than the nickel-metal-hydride battery in the first-generation NX 300h it replaced, and the same generation of hybrid system as the current Toyota range. Lexus's own parts catalogue carries a lithium-ion caution label for the car.

For a used buyer the consequence is the same as on the newer Toyotas: the reconditioning trade that makes older NiMH Lexus hybrids cheap to repair does not extend to this pack. If it ever needs attention, expect a Lexus part at a Lexus price.

Lexus's warranty, plainly

Defect cover for 5 years, extendable to 10 with the annual check. Gradual capacity loss is not a defect. Lexus does not publish whether the battery cover transfers to a second owner — we have marked that unavailable rather than assume — and its terms state that measurement methods and replacement decisions rest solely with Lexus Australia.

That combination is why an independent, dated measurement is worth having on a used NX 350h: it is the only evidence of the pack's condition that is not Lexus's. Full detail: Lexus battery warranty in Australia.

What's normal

A well-kept NX 350h at three or four years should be unremarkable. These are gently worked packs in a car that tends to be garaged and serviced on schedule. The variation you see between cars comes from use — a car that did long highway runs behaves differently from one that did school runs — more than from anything inherent.

What to check before you buy

  • Cell-group voltage spread

  • Cooling intake condition

  • Stored and pending hybrid fault codes

  • Lexus health-check history for the extended cover

  • Lexus's written position on transfer for that specific car

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Battery chemistry: lithium-ion, consistent with Lexus's parts catalogue for the NX 350h. Warranty terms from Lexus Australia. Verified 15 September 2026.