Man tests his Kia Niro EV's battery after 265,000 miles to find out if his vehicle is a hidden gem or an expensive lemon
Published on Nov 11, 2026 at 7:10 AM (UTC-5)
by Daisy Edwards
Last updated on Nov 11, 2026 at 7:10 AM (UTC-5)
Edited by
Mason Jones
A used Kia Niro electric car with more than 265,000 miles on the clock might sound like a risky purchase, particularly when its battery could cost thousands of dollars to replace.
But one YouTuber decided to take a chance on a high-mileage Kia Niro EV after finding it at auction for just £4,100.
Efficient Alex bought the 2021 electric car sight unseen, having set himself a £5,000 budget for his next EV.
After spending several months getting it back into roadworthy condition, he wanted to investigate the one thing that could make or break his bargain purchase: the battery.
The Kia Niro EV has driven an incredible 265,000 miles
The Kia Niro EV had previously been used as a taxi, averaging approximately 55,000 miles every year.
Although it still drove well, Efficient Alex had already discovered a few problems, including worn bearings causing noise from the motor and gearbox.
However, the battery was his biggest concern.
“Because this car with 265,000 miles has done an average of around 55,000 miles a year for the last five years,” he explained.
The 2021 Kia Niro EV has a 64kWh usable battery, with a larger gross capacity of approximately 67.5kWh.
It also uses NMC battery chemistry and has an active thermal management system designed to regulate temperatures and protect its individual cells.
According to research from vehicle telematics company Geotab, average EV battery degradation was approximately 2.3 percent annually.
Using that figure, Alex estimated that his Kia might have around 88.5 percent battery health remaining after five years.
Three battery tests produced some surprising results
The first test was completely free and involved using the Car Scanner smartphone app alongside an OBD diagnostic adapter.
This allowed Alex to access information stored in the car’s battery management system.
The results revealed that the Kia had accumulated 22,757 operating hours, recorded 1,955 charging sessions and received approximately 57,900kWh of charging energy.
But the biggest surprise was the battery health reading.
The app reported 100 percent battery health, despite the car having traveled more than 265,000 miles.
Alex then arranged a professional assessment through Vault Test, which also returned a 100 percent reading.
However, specialists explained that Kia calculates battery health against its 64kWh usable capacity rather than the larger gross capacity.
This means the reading can remain at 100 percent even if some degradation has occurred, provided the battery retains at least its reference capacity.
The final assessment came from AVILOO, using its independent Flash Test through Battery Health Check.
Unlike the previous methods, this assessment uses its own calculations and comparisons with similar vehicles rather than simply reporting the battery management system’s reading.
And this time, the result was noticeably different.
The Kia was given a battery health score of 85.3 percent, with the individual cells also showing a healthy balance.
The high-mileage EV turned out to be better than expected
Despite the lower independent reading, Alex was impressed by how well the battery had held up.
The car still charged normally and was capable of covering almost 300 miles on a single charge in his real-world driving.
He also suggested that the vehicle’s previous use could have helped its battery, as it had been regularly driven and charged rather than sitting unused for long periods.
“You can have a vehicle with very high mileage on an EV and if it’s looked after, it can really retain that battery health,” one of the specialists explained during the assessment.
Alex ultimately concluded that buyers shouldn’t automatically be frightened of high-mileage electric cars.
However, he recommended getting an independent battery health assessment before spending thousands on a used EV.
After all, a car with 265,000 miles might look like an expensive lemon, but this Kia Niro EV suggests it could still have plenty of life left in it.
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Daisy is a technology and automotive journalist covering artificial intelligence, consumer tech, Apple news, cryptocurrency, emerging technologies, and transportation innovation. Since joining the team in 2025, she has reported on everything from AI-powered startups and major iOS updates to viral car stories and the latest developments shaping transportation and the digital economy. Drawing on her background in automotive journalism and a degree in History and Journalism from Goldsmiths, University of London, Daisy specializes in breaking down complex topics into clear, engaging reporting for a global audience. Her work spans cutting-edge technology, innovative vehicles, and the people driving change across both industries. Daisy has gained first-hand access to some of the world's most talked-about technologies and innovators, including meeting Tesla's Optimus humanoid robot during its first European appearance in London. She has also discussed the future of space exploration with an astronaut, bringing unique insights and real-world perspectives to her coverage of emerging technology.
