NiMH

Toyota Highlander Hybrid 2006-2007 (MHU28) Hybrid Battery

The Toyota Highlander Hybrid 2006-2007 (MHU28) Hybrid Battery is the high voltage battery in the Toyota Highlander Hybrid (2006-2007).

At a Glance

NiMH chemistry
288 volts nominal
30 modules
air-cooled; battery cooling blower cooled

Specifications

Chemistry	NiMH
Cell format	prismatic
Nominal voltage	288 V
Modules	30
Module voltage	9.6 V
Cooling	air-cooled; battery cooling blower
Location	cabin area, floor pan cross member under the rear seat
Weight	69 kg

Cars That Use It

Toyota Highlander Hybrid 2006-2007 MHU23/MHU28 series, 3.3L V6 4WD-i Run the checklist

What Goes Wrong

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

Owner complaints NHTSA lists under the Hybrid Propulsion System component for the Toyota Highlander Hybrid, by model year: 2006: 46 · 2007: 14. These are all hybrid system complaints, owner reported and unverified, not only battery faults, as of 2026-10-07.
Toyota service bulletin T-SB-0074-20 (August 2020) covers 2006-2019 Highlander Hybrid vehicles that store DTC P0A80/P1AC000 and/or P0A7F/P1A8000 because dust or debris has built up in the HV battery cooling fan or intake filter; when those codes are present the bulletin's procedure calls for replacing the HV battery and cleaning the cooling fan and filter. (static.nhtsa.gov: MC-10179698-9999.pdf, 2026-10-07)

Symptoms

Toyota service bulletin T-SB-0074-20 describes the malfunction indicator lamp (MIL) coming on with DTC P0A80/P1AC000 and/or P0A7F/P1A8000 stored on 2006-2019 Highlander Hybrid vehicles when the HV battery cooling fan or intake filter is clogged with dust or debris. (static.nhtsa.gov: MC-10179698-9999.pdf, 2026-10-07)
A keyword search of the 46 Hybrid Propulsion System complaints NHTSA lists for the 2006 Toyota HIGHLANDER HYBRID finds that 17 mention warning light, 12 mention loss of power or reduced power, 17 mention stalling or shutting down (complaint text is owner-reported and unverified; as of 2026-10-07). (NHTSA complaints, 2006 Toyota Highlander+Hybrid, 2026-10-07)
A keyword search of the 14 Hybrid Propulsion System complaints NHTSA lists for the 2007 Toyota HIGHLANDER HYBRID finds that 3 mention warning light, 1 mention loss of power or reduced power, 11 mention stalling or shutting down (complaint text is owner-reported and unverified; as of 2026-10-07). (NHTSA complaints, 2007 Toyota Highlander+Hybrid, 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.

Recalls

11V342000 2006-2007 Transistors in the inverter's power module may have weak solder joints that heat can damage during high-load driving, which can turn on warning lamps.
13V396000 2006-2007 Transistors in the inverter's Intelligent Power Module can run hotter than their solder supports, which can damage them.

Check the exact car by VIN at nhtsa.gov/recalls.

Warranty

Toyota's 2006 Highlander Hybrid Warranty & Maintenance Guide lists the hybrid battery under the Toyota Hybrid System Warranty for 96 months or 100,000 miles, whichever comes first (2006 model year confirmed; no 2007 guide was found). (techinfo.toyota.com: T-MMS-06HighlanderHV.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

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 Toyota. Names and part numbers are used only to identify the vehicle and the part.