The honest version: full pack replacements are rare, expensive, and almost never what actually happens. Module-level repair is the normal outcome, and it costs a fraction of the headline figure. What you're really buying when you check a battery is the difference between those two scenarios.
Why we won't quote you a number
Every page you'll find on this topic has a confident table of pack prices on it. We're not going to add another one, because the honest position is that a credible figure doesn't exist in the abstract — and a wrong one either scares you off a good car or lulls you into a bad one.
What the number actually depends on:
What is actually being replaced
A single module, a contactor, a battery management module, or the whole pack. These are different jobs by an order of magnitude, and the dash warning that sent you looking often can't tell them apart.
Where the part comes from
New from the manufacturer, remanufactured, or salvaged from a written-off car. Availability for a given model changes month to month in Australia, and so does the price.
Who is allowed to do the work
Some manufacturers will only replace complete packs through their own network. Others permit module-level repair by independent specialists. That single policy difference moves the bill more than pack size does.
Whether you're paying at all
Most high-voltage packs carry eight years of manufacturer cover with a capacity floor around 70%, and that cover generally transfers with the car. Establishing where a specific VIN sits is free and takes one phone call.
So the useful thing to do isn't to memorise a price. It's to get a written quote against the actual VIN and the actual fault before you commit to anything — and, better, to measure the pack before you buy the car so the question never arises. See what an inspection costs and how to check the warranty position.
What actually happens instead
Packs are built from modules, and modules fail one at a time. A specialist can diagnose the offender, replace or rebalance it and return the car with the rest of the pack untouched. The independent repair sector in Australia has grown quickly, and that has widened the options between "it's fine" and "you need a new pack".
Single module
The usual outcome
Diagnose the failing module, replace it, rebalance the pack. Typically a day or two off the road, and a small fraction of a full pack replacement.
Contactor or BMS
Often misdiagnosed
Reads like a catastrophic battery failure on the dash. Isn't one. Cheaper again than module work, and regularly mistaken for a dead pack.
Refurbished pack
The middle path
Second-hand or remanufactured, increasingly available for common models and well short of a new pack. Ask what warranty the rebuilder offers.
When someone else pays
Most high-voltage batteries carry around eight years of manufacturer cover with a capacity floor near 70%. Inside that window, a genuine defect is the manufacturer's cost — gradual capacity loss above the floor generally isn't. Australian Consumer Law also runs alongside the written warranty and can extend your position on a major failure in a car that should reasonably have lasted longer.
Which is why the single most valuable thing to establish before you buy is how much cover is left and whether it transfers to you. That's the whole of the battery warranty check page.
Pricing the risk into an offer
Buyers tend to do one of two things: ignore battery risk completely, or assume a catastrophic bill is imminent and refuse to buy anything. Both are wrong, and both cost money. A measured state of health figure lets you price the actual exposure.
In warranty, healthy pack
No adjustment. The risk sits with the manufacturer, and it's a genuine selling point for the car.
In warranty, SoH near the floor
Potentially the best buy on the lot — a documented claim before the cover expires can mean a new pack. Get the reading in writing, dated.
Out of warranty, in-range SoH
Price it like any ageing component. The realistic exposure is usually a module repair rather than a whole pack — a very different number, and one worth establishing before you negotiate.
Out of warranty, wide cell spread
The one to walk away from, unless the price already assumes a rebuild. This is the scenario the whole inspection exists to catch.
Which bucket a car falls into takes about an hour to establish — see how the test works, or what's normal for its age.
Measure it now, or find out the expensive way.
Know exactly what the pack in that car is doing before you pay for it.