Hybrid Battery Test

NiMH

Lexus NX 300h Hybrid Battery (2015-2021)

The Lexus NX 300h Hybrid Battery (2015-2021) is the high voltage battery in the Lexus NX 300h (2015-2021).

At a Glance

Specifications

ChemistryNiMH
Nominal voltage244.8 V
Modules34
Module voltage7.2 V
Coolingair (battery intake ducts, per DM)
LocationCabin floor pan cross member under the second-row rear seats, concealed by fabric covers
Weight54 kg

Cars That Use It

What Goes Wrong

Reported failures, each from a source listed below, as of October 7, 2026.

    Symptoms

    • The Lexus dismantling manual says a ground-fault monitor watches for high-voltage leakage to the metal chassis while the vehicle is running; if it detects a fault, the master warning light comes on and the display shows "Hybrid system malfunction". (techinfo.toyota.com: L-DM-009-D.pdf, 2026-10-07)
    • The 2019-2021 NX 300h Warranty and Services Guides schedule a periodic check or inspection of the HV battery cooling intake filter as a maintenance item. (assets.sia.toyota.com: L-MMS-21NX300H.pdf, 2026-10-07)

    Same Electrical Spec

    These packs share this one's chemistry, voltage and module count. That is a spec match only. It does not mean the parts fit each other, so check with a technician.

    Warranty

    Lexus's 2015, 2018 and 2019 NX 300h Warranty and Services Guides list the hybrid battery under the Hybrid System Warranty for 96 months or 100,000 miles, while the 2020 and 2021 NX 300h guides list a separate Lexus Hybrid Battery Warranty of 10 years or 150,000 miles from the in-service date, whichever occurs first. (assets.sia.toyota.com: L-MMS-20NX300h.pdf, 2026-10-07)

    How battery warranties work.

    Get This Pack Tested

    Do not open it yourself. The pack can hurt you with the car switched off.

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    How to test a hybrid battery safely

    Sources

    1. techinfo.toyota.com: L-DM-009-D.pdf
    2. techinfo.toyota.com: L-DM-013-D.pdf
    3. techinfo.toyota.com: L-ERG-026-D.pdf
    4. fueleconomy.gov: 35785
    5. fueleconomy.gov: 42854
    6. assets.sia.toyota.com: L-MMS-21NX300H.pdf
    7. assets.sia.toyota.com: L-MMS-15NX300H.pdf
    8. assets.sia.toyota.com: L-MMS-18NX300H.pdf
    9. assets.sia.toyota.com: L-MMS-19NX300h.pdf
    10. assets.sia.toyota.com: L-MMS-20NX300h.pdf

    Last updated October 7, 2026. Failure and recall notes are as of that date. Spotted a mistake, or speaking for a maker? Report an error.

    Hybrid Battery Test is independent. It is not affiliated with, sponsored by or endorsed by Lexus. Names and part numbers are used only to identify the vehicle and the part.