MajorCommonElectrical

Toyota Prius: PHV Lithium-Ion Traction Battery Capacity Degradation

PHV Lithium-Ion Traction Battery Capacity Degradation is a common electrical fault on the Toyota Prius on the 2012–2022 cars, and we rate it major. Putting it right costs $3,500 to $8,500 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 42 documented faults on the Toyota Prius.

Vehicle: Toyota Prius
Only on: plug-in
Years: 2012–2022
Fuel: hybrid
Gearbox: cvt
System: Electrical

This page covers the Toyota Prius as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Toyota Prius faults42 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph for this fault yet. We would rather show none than show a picture of something else.

What goes wrong

The ZVW35 and ZVW52 Prius PHV/Prime uses lithium-ion cells for the plug-in EV buffer rather than the NiMH pack found in standard Prius. Lithium cells are more susceptible to calendar ageing, high-temperature cycling, and repeated shallow charge/discharge. Documented in NHTSA complaints and Toyota service bulletins, affected vehicles show EV range dropping from 25–50 km new to under 15 km within 5–8 years. Capacity loss accelerates in vehicles charged daily from near-empty or stored at full state of charge in hot climates. Toyota has no cheap fix; the lithium module must be replaced as an assembly.

What you would notice

EV-only range noticeably shorter than claimed, often 50% or less of original
READY light illuminates in HV mode almost immediately after departing on a full charge
HV battery warning triangle (amber) displayed on instrument cluster
Large individual cell voltage variance reported by OBD scanner
More frequent ICE engagement at low speed compared to a healthy example

How to check it

Where to look. Under rear seat/cargo floor — lithium PHV module sits beneath the boot floor or rear seat base

Check EV RANGE readout on MID after a full charge — should show at least 20 km (ZVW35) or 35 km (ZVW52 Prime).
Inspect for DTCs B0000 through B007F and any HV warning icons.
If a workshop inspection is possible: Use Techstream or third-party OBD tool to read HV battery State of Health (SOH) and individual cell voltage spread; a spread above 0.3 V across cells indicates degradation.

What it costs to put right

$3,500 to $8,500 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“Can you show me the EV range displayed after a full overnight charge?”
“Has the HV or lithium battery ever been replaced or reconditioned?”
“Is there any history of amber or red triangle warnings on the dash?”

Now check the Toyota Prius you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.

Toyota Prius buyer questions

Is phv lithium-ion traction battery capacity degradation serious on a Toyota Prius?

We rate it major and common on the Toyota Prius. The ZVW35 and ZVW52 Prius PHV/Prime uses lithium-ion cells for the plug-in EV buffer rather than the NiMH pack found in standard Prius. Lithium cells are more susceptible to calendar ageing, high-temperature cycling, and repeated shallow charge/discharge. Documented in NHTSA complaints and Toyota service bulletins, affected vehicles show EV range dropping from 25–50 km new to under 15 km within 5–8 years. Capacity loss accelerates in vehicles charged daily from near-empty or stored at full state of charge in hot climates. Toyota has no cheap fix; the lithium module must be replaced as an assembly.

How much does it cost to fix on a Toyota Prius?

$3,500 to $8,500 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Toyota Prius years are affected?

Our research records this fault on the 2012–2022 Toyota Prius. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.

How do I check for it before I buy?

Check EV RANGE readout on MID after a full charge — should show at least 20 km (ZVW35) or 35 km (ZVW52 Prime). Inspect for DTCs B0000 through B007F and any HV warning icons. If a workshop inspection is possible: Use Techstream or third-party OBD tool to read HV battery State of Health (SOH) and individual cell voltage spread; a spread above 0.3 V across cells indicates degradation. Look here: Under rear seat/cargo floor — lithium PHV module sits beneath the boot floor or rear seat base