Kia EV6 Battery Degradation: What Is Normal at Your Mileage?

You are standing next to a used EV6, or scrolling a listing at eleven at night, and you have a number. Ninety-four per cent. Eighty-nine. Whatever the seller's app says.

The only question that matters is whether that figure is good, bad or unremarkable for a car of this age and mileage, and almost nobody publishes the benchmark you need to answer it.

So here it is, along with the studies behind it and the one thing that can make the number misleading regardless of how the car has been treated.

EV6 degradation benchmarks

The 62,000-mile row is the one to trust, because it is measured rather than estimated. The others are drawn from owner reports and should be read as ranges, not targets. The spread between individual cars is wide, and heavy DC fast charging, hot climates and highway-heavy use all pull toward the lower end of each band.

The measured number, and where the EV6 ranks

This is the part most EV6 sellers do not know, and it is worth having to hand before anyone starts negotiating.

Swedish used car marketplace Carla compiled 9,954 battery health tests carried out between 2022 and 2026, measuring what each model retained at around 100,000 km, roughly 62,000 miles. As reported by InsideEVs, the EV6 and its 77.4 kWh pack averaged 95.95 per cent, placing third overall.

The two cars above it were also Korean: Kia's own e-Niro led the study at 97.25 per cent, with the mechanically related Hyundai Kona Electric at 97.18 per cent. Behind the EV6 came the Volvo XC40 Recharge at 94.70 per cent and the Polestar 2 at 94.35 per cent. Even the lowest-placed car in the top twenty held more than 91 per cent.

One detail makes the EV6 result more impressive than the raw ranking suggests. The e-Niro and Kona are older cars whose packs charge at under 80 kW, and that gentler rate reduces the heat associated with cell ageing. The EV6 runs an 800-volt architecture and charges roughly three times as fast, yet came close to matching them.

A separate and smaller analysis by Swedish broker Kvdbil, covering 1,366 used vehicles, also placed the EV6 at the top for battery retention, with eight in ten cars across that whole sample holding 90 per cent or more.

Owner reports line up. On the Kia EV forums, one EV6 RWD owner reported 97.2 per cent at 52,000 miles after eighteen months of nightly home charging to 80 per cent. Another reported 98.1 per cent at 45,000 km over nineteen months.

None of that guarantees anything about the specific car in front of you. What it does mean is that a healthy EV6 in the mid nineties at 60,000 miles is the expected result rather than a lucky one.

When a low number is not what it looks like

Here is the thing that turns a good negotiation into a bad one.

Every figure you are being quoted originates in the battery management system's own estimate of usable capacity, whether it comes from the dashboard, an app or an OBD scanner. That estimate calibrates by observing the pack across a wide state-of-charge range.

An EV6 that has spent months charging nightly to 80 per cent and rarely dropping below 30, which is exactly what sensible advice recommends, has given its BMS very few opportunities to check itself against the top and bottom of the range. The estimate then drifts, while still presenting with complete confidence.

I watched an EV read 89.9 per cent and land near 83 after one deep cycle, same pack, same week. It moves the other way just as often, with cars reading low and recovering several points after a full charge and a long drive. I covered the mechanics in why a tracking app said 89.9 per cent and the real figure was 83.

So if you are a buyer looking at a number below the band, the useful question is not "how much discount does this justify." It is "when did this car last see a wide charge cycle." And if you are a seller whose car reads lower than you expected, that is worth resolving before you list rather than after a buyer has anchored on it.

This matters more on the EV6 than on most cars, precisely because the measured average is high. A reading in the high eighties at 60,000 miles sits well below what the study found, which makes it worth a proper look rather than an automatic discount.

What a number below the band actually costs you

Two things worth separating, because buyers routinely conflate them.

Ordinary degradation is a range issue. An EV6 that went 300 miles when new might go 270 after several years of commuting. That is inconvenient, it is priced into the market, and it is not a fault.

Warranty territory is different and much further away. Kia's cover steps in below 70 per cent, and in owner reports and forum data sets it is rare to see an EV6 anywhere near that threshold without a genuine defect. If a car genuinely tested near 70 per cent inside the warranty window, that is a repair claim rather than a negotiating point, which is a much better outcome for the buyer than a discount.

The full terms, including how they differ between the US and UK and what happens when the car changes hands, are in my guide to Kia EV battery warranties.

How to establish the number properly

If you are selling, the problem is not your figure. It is that your buyer cannot check it, and a screenshot from your phone carries exactly as much weight as your word.

This is the gap EV TrustSeal was built to close, and Kia is one of the 46 manufacturers I support.

You connect your Kia account through a read-only connection, using Kia's own login screen, so your credentials never touch my servers. Battery data only, no vehicle controls, and you can revoke access whenever you like.

Then one charging session does the work. Drive until the pack is under 20 per cent, plug in to home AC, and press Start Audit. Charge to at least 80 per cent in one uninterrupted session. The audit completes at 80 per cent and your car simply carries on charging, so there is nothing to stop, set or watch. The result arrives within hours.

That wide swing is the point. Rather than repeating the dashboard's estimate, the system measures how much energy the pack actually delivered across the window and compares it against original capacity for your specific vehicle. It is also why the result is not subject to the drift described above.

The certificate is locked to your VIN and carries a QR code resolving to a public verification page, so your buyer checks it directly without contacting you.

Frequently Asked Questions

What is normal battery degradation for a Kia EV6?

Less than most people expect. A Swedish study of 9,954 battery health tests measured the EV6 averaging about 96 per cent retention at 62,000 miles. Loss is front-loaded, so most of it happens in the first couple of years and the curve then flattens.

Is 90 per cent battery health good for an EV6?

It is below average for the model. Carla's study of nearly 10,000 battery tests put the EV6 at about 96 per cent at 62,000 miles, so 90 per cent is on the low side unless the car has very high mileage, has been fast charged heavily, or has lived somewhere hot. It may also reflect a stale battery management system estimate rather than a genuinely weaker pack, which is worth establishing before anyone negotiates on it.

Does the EV6 have good battery life?

Independent testing has been favourable. In Carla's study of 9,954 battery health tests, the EV6 placed third at about 96 per cent retention at 62,000 miles, behind two other Korean cars including Kia's own e-Niro. It managed that despite charging roughly three times faster than the two models above it.

How long will an EV6 battery last?

Longer than most owners keep the car. Kia's capacity cover runs to 70 per cent for 10 years or 100,000 miles in the US, and reaching that threshold without a defect is rare in the data available so far.

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Check the number, then check the number

An EV6 with a figure inside the band for its mileage is an ordinary healthy car, and the data says most of them are. The trouble is that the figure itself is the least reliable part of the transaction, and both sides are usually working from a screenshot.

If you are selling and buyers keep using the battery to argue your price down, giving them something they can verify themselves is the right move. evtrustseal.com