Kia Comes Out on Top in EV Battery Degradation Study

• A Swedish study on used electric and plug-in hybrid cars aimed to understand the mechanics of battery degradation.

• 80% of all vehicles tested retained at least 90% of their battery capacity.

• Kia models topped the EV and PHEV categories, but researchers say usage has a bigger impact than manufacturer.

Battery degradation is a popular topic when it comes to electric vehicles and their projected longevity, with many claiming that batteries will have to be replaced after only a few years in order to keep a decent range.

The reality doesn’t seem to be so grim, however, as a study on used EVs and PHEVs conducted in Sweden by car broker Kvdbil shows that batteries are more resilient than expected.

Indeed, out of 1,300 vehicles tested, 80% of them had lost 10% or less of their original battery capacity. The study doesn’t specify the age of the vehicles it tested, but it did confirm that as expected, the 20% that did lose more than 10% capacity are mostly older vehicles with higher mileage.

Despite this, researchers say that a number of usage related factors impact battery health more than age or mileage, such as ambient temperatures, driving style, and charging habits.

Only charging the battery up to 80% under normal circumstances and limiting level-3 fast charging sessions are still believed to contribute to a healthier battery in the long run.

This study highlighted another surprising element. Indeed, Kia vehicles were found to have consistently suffered less battery damage than comparable used cars from other automakers, especially the EV6 and the Sportage Plug-in hybrid.

In fact, the South-Korean brand occupies the two top spots in both EV and PHEV rankings, with the Niro EV following the EV6 and the Optima PHEV following the Sportage PHEV.

No Hyundai models are listed in the top then of either category, but this seems more likely due to a smaller sample size than actual differences between Hyundai and Kia vehicles, which usually share most of their mechanical elements, including their high-voltage batteries.

The 10 brands that best retain their battery’s state of health according to the Study are:

1. Kia
2. Audi
3. Opel
4. Tesla
5. Mercedes-Benz
6. Peugeot
7. Volvo
8. BMW
9. Volkswagen
10. Skoda

In terms of individual models, electric vehicles are ranked as such:

1. Kia EV6
2. Kia Niro EV
3. Tesla Model Y
4. Opel Mokka-e
5. Mazda MX-30
6. Audi Q4 e-Tron
7. Fiat 500e
8. Volvo XC40 Recharge
9. Citroën e-C4
10. Volkswagen ID.4

And PHEVs are as follows:

1. Kia Sportage
2. Kia Optima
3. Volvo XC60
4. Kia Ceed
5. Volvo V60
6. Peugeot 3008
7. BMW 530e
8. Volkswagen Passat GTE
9. BMW X1
10. BMW 330e

Despite this comprehensive ranking, Kvdbil claims that the car or the battery’s manufacturer doesn’t have a huge impact on the degradation observed after a few years on the road, not as much as environmental factors and driver habits, in any case.

This goes to show that electric vehicles can remain entirely usable many years after they roll out of the assembly line, provided that the driver has a basic grasp of how their batteries work and how they can help reduce degradation.

It seems better education about electric vehicles for the general public could help dispel the persisting myth that they are throw-away cars.

Source: InsideEVs.com