The new odometer: why an EV's battery is the number that matters
On a petrol car, mileage tells the story. On an electric car, it can lead you astray. Here is what really decides a used EV's value, and how to check it before you buy.
On an electric car, the battery is the expensive part, and its health is what to check first.
When you buy a used petrol car, mileage is one of the first things you check, and for good reason. On an electric car, that habit can steer you straight past the thing that costs the most to replace. A high mileage EV with a healthy battery can be a great buy, and a low mileage one with a tired battery can be a money pit. As electric cars flood onto the used market, more buyers than ever will need to learn how to read the new odometer: the battery.
The short version
- On an EV the battery is the expensive part, so its State of Health matters more than the number on the dash.
- Batteries fade slowly rather than fail suddenly. Above 90 percent is strong, around 85 percent is fine, below 80 percent means asking more questions.
- How a car was charged matters more than how far it was driven. A life on rapid chargers ages a pack about twice as fast as gentle home charging.
- The usual checks still apply. Damage history counts for more on an EV, because the pack sits low and flat under the floor.
Used EVs are about to be everywhere
Five years ago, an electric car on a used forecourt was a curiosity. That has changed fast. Battery electric cars have gone from under one in ten new sales in the EU to about one in five, according to the European car industry body, ACEA. Their share rose from 9.1 percent in 2021 to 17.4 percent in 2025, with a dip in 2024 after several countries trimmed their subsidies, and it has since reached 20.7 percent in the first half of 2026.
Electric is going mainstream
Battery electric share of new car registrations in the EU
That is new cars, but it tells you exactly where the used market is heading. Today's new EVs are the used EVs of the next few years. As that wave comes off its first lease and finance deals and lands on the second hand market, far more buyers will face a question petrol buyers never had to ask: how healthy is the battery?
Check the VIN before you buy
See a car's real mileage, damage and import history across 30+ countries, in under a minute. Electric or not.
Example: WBA3A5G59DNP26082Free preview included
What battery health actually means
Battery health is usually written as State of Health, or SoH: the percentage of the original capacity the battery still holds. A car that left the factory at 100 percent might sit at 91 percent after a few years, meaning it now stores about 91 percent of the energy it once did, so the range is a little shorter.
Batteries rarely fail all at once. They fade, slowly and quietly, and that fade is what you are trying to measure. As a rough guide, above 90 percent is strong, around 85 percent is fine, and below 80 percent is a reason to slow down and ask more questions.
A high mileage EV with a healthy battery can be the smarter buy. The number on the dash no longer tells the whole story.
Five things to check
Ask for the battery's State of Health. A seller who looks after the car can usually tell you, ideally with a readout from the car or an app to back it up. A blank look, or "the range seems fine", is not the same as a number.
Compare the range now with the range when new. Charge the car to full and look at the estimated range on the dash, then compare it to what the model was rated for when new. A quick check: if a full charge shows about 210 km on a car rated near 260 when new, that points to roughly 80 percent health. A big shortfall is the battery telling you it has lost some capacity.
Ask how it has been charged. Gentle home charging overnight is the kindest thing for a battery. A car that lived on rapid chargers, or was routinely left sitting at 100 percent, tends to age faster than its mileage suggests. Most makers suggest keeping daily charging between about 20 and 80 percent, since the top slice is the hardest on the cells.
Check what is left of the battery warranty. Most EV batteries come with a long warranty, often around eight years or 160,000 km, with a promise to replace the pack if capacity drops below 70 percent. Find out how much of that cover remains and whether it passes to you as the new owner.
Think about where it has lived. Years in constant heat are harder on a battery than a mild climate, and so are long spells left fully charged or fully flat. The car's past life shapes its battery as much as the miles on the clock, and on an imported car that past is exactly the part the paperwork tends to leave behind.
How batteries age
Modern packs are lasting well. The fleet data company Geotab measured more than 22,700 electric cars across 21 models and found an average loss of 2.3 percent of capacity a year, which projects to roughly 82 percent still there after eight years. So a five year old EV sitting in the high 80s is usually doing just fine.
The biggest single factor is how the car is charged. In that same data, cars leaning on high power DC chargers above 100 kW lost capacity at up to 3 percent a year, against about 1.5 percent for cars charged at lower power, so roughly twice the fade for the same years on the road. Constant heat adds a little more on top. The chart below draws those two rates out over a decade.
How charging habits change the curve
Battery capacity over time at Geotab's measured low power and high power rates
The other EV buying traps
The battery is the headline, but a few EV specific traps catch buyers out, and none of them show up on a quick test drive.
Is the battery owned or leased? Some older electric cars were sold with the battery on a separate monthly lease that transfers to the new owner. The car looks cheap, then a bill arrives every month. Always confirm the battery is owned outright.
What is locked behind software? On some EVs, range, faster charging or comfort features are unlocked by software or sit behind a subscription, and that may not carry over to a second owner. Check what is actually enabled on this car, not what the model can do in theory.
Does it have a heat pump? It sounds minor, but a heat pump makes a real difference to winter range. The same model with and without one can behave very differently in the cold.
Which plug, and how fast? Confirm the charging connector and the car's real maximum charging speed. A cheap EV that only charges slowly is a different daily life from one that rapid charges in half an hour. Check the charging cable is included too, as they are not cheap to replace.
Damage history matters more, not less. A knock that dents a petrol car can be far more serious on an EV, where the battery pack sits low and flat under the floor. Flood or crash damage to that pack is a genuine safety issue, so an EV's accident and damage history is well worth reading before you commit. The same goes for the mileage behind it, which is easier to rewrite than most buyers expect.
Electric or petrol, the rule is the same: the things that cost you most are the ones you cannot see in person. On an EV that means the battery and how it was treated, on top of the usual mileage, damage and ownership trail. Whichever service you use, run the VIN before you sign.
Know the car before you pay
Mileage, recorded damage, finance and import history across 30+ countries, in one quick report.
Example: WBA3A5G59DNP26082Free preview included
Not sure yet? See what a full report looks like first
Frequently asked questions
Does high mileage matter on an electric car?
Less than you would think for the battery, which ages with time and charging habits more than with distance. Mileage still matters for everything else: tyres, suspension, brakes and interior wear. So check the battery health and the mileage, not one instead of the other.
What counts as a good State of Health on a used EV?
As a rough guide, above 90 percent is strong, around 85 percent is fine for a car a few years old, and below 80 percent is a reason to slow down and ask more questions. Always read the figure against the car's age, because a five year old EV in the high 80s is doing perfectly well.
How long do EV batteries actually last?
Most come with a warranty of around eight years or 160,000 km guaranteeing at least 70 percent capacity, and real world data suggests many will comfortably outlast that. Geotab measured an average loss of 2.3 percent of capacity a year across more than 22,700 electric cars, which points to roughly 82 percent still there after eight years. Sudden failure is rare. Slow, gradual fade is the norm.
Is rapid charging bad for the battery?
The occasional rapid charge on a long trip is fine. The issue is relying on high power DC charging as the everyday method. In Geotab's data, cars leaning on chargers above 100 kW lost capacity at up to 3 percent a year, against about 1.5 percent for cars charged at lower power. A car that has lived its life on rapid chargers is worth a closer look.
Should I worry about buying a used EV for winter?
Range drops in the cold for every EV, often noticeably, so judge the car on its warm weather range and expect less in deep winter. A heat pump helps a great deal, so it is worth checking whether this particular car has one.
Can a VIN check tell me anything useful about an electric car?
Yes, and on an EV some of it matters more. A history check reads the recorded mileage, accident and damage records, finance and theft flags and the countries the car has been registered in. Damage records are especially worth reading on an EV, because the battery pack sits low and flat under the floor, so a knock or a flood that a petrol car would shrug off can be a genuine safety issue. What a VIN check cannot give you is State of Health: that has to come from the car itself.
Sources
- ACEA: EU new car registrations. Battery electric share 9.1% in 2021, 17.4% in 2025 and 20.7% in the first half of 2026. Read
- Geotab: EV battery degradation study across more than 22,700 cars and 21 models. Average loss 2.3% a year, about 1.5% on low power charging against up to 3% on high power DC above 100 kW. Read
- GreenCars and manufacturer warranties: EV battery cover, commonly 8 years or 160,000 km with a 70% capacity guarantee. Read
- Recurrent: how to check an EV's battery health before buying used, including the full charge range test and State of Health bands. Read
- US Department of Energy: cold weather reduces electric car range, used for the winter range note. Read
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