Why Chinese dealers shun five-year-old EVs despite the battery data

Buy a five-year-old petrol hatchback and the trade knows roughly what it is worth. Age, mileage, service history, a compression check if anyone is being thorough. Buy a five-year-old electric car in China and about four dealers in five will simply decline to take it in part-exchange.

That figure comes from the International Energy Agency's Global EV Outlook, cited this week by Rest of World in a report on what happens when a country's electric fleet starts to get old. China has 44 million EVs on its roads and has been the world's largest EV market for a decade, which makes it the first place where large numbers of them are ageing at once. A three-year-old EV there now resells for around 45 per cent of its original price, down from almost 55 per cent in 2023, according to the China Automobile Dealers Association.

It would be easy to read those numbers as proof that EV batteries fall apart. The measured evidence says otherwise. Geotab's January study of 22,700 electric vehicles across 21 light- and medium-duty models in Canada, the US and Europe put average degradation at 2.3 per cent a year — a battery still holding 81.6 per cent of its original capacity after eight years.

Charlotte Argue, Geotab's senior manager of sustainable mobility, told Electric Autonomy that the studies have been running for years precisely to establish what normal looks like. On the feared end-of-life cliff, where capacity falls off a shelf, she was blunt: "We haven't seen much evidence of that to date, so I think we need to wait a few more years before we start seeing it, but that's a good sign, because that means that these batteries are long lasting, performing really well." Eight of the 11 models carried over from the 2023 data set have settled at 1.4 per cent a year.

Charging habits move the number. Vehicles that took more than 12 per cent of their charge above 100 kW degraded at 3.0 per cent a year. Heat compounds it. Harsh Chaturvedi, an automotive consultant in the UAE who co-founded the fleet company MyEVPlus, described Tata taxis in his fleet driven up to 80,000 km a year and fast-charged constantly, losing as much as 8 per cent of capacity annually and half their value inside twelve months.

Which is the actual point. A carefully driven private car and a hammered taxi can present identically on a listing.

"Two vehicles of the same age and mileage can potentially have very different battery health depending on how they were driven and charged," Chaturvedi told Rest of World. "The market does not always have a simple way to reflect this difference in price."

The five-year mark is not arbitrary. Manufacturers typically warrant the battery for eight years or 160,000 km, and a replacement can cost a third of a new car. Every year of age eats the remaining cover, and buyers can do that arithmetic without help. Chaturvedi said Gulf buyers back away at the same point: "Customer interest drops significantly after the fifth year. The fifth year therefore becomes an important psychological and commercial point in the used EV market."

Karl Brauer, executive analyst at iSeeCars, added the other half. Lenders and leasing companies model losses at three and five years because that is how long typical loans and leases run, and EVs fall faster in those models because first owners pay a premium for the newest technology and for what the car says about them. "Used car shoppers are much more value-oriented," he said.

Brauer told Rest of World that modern EVs can report battery health through a diagnostic port, and third-party certifiers exist. The practical obstacle is that dealers rarely ask for those readings, and still price on age, mileage, warranty and model reputation instead — four proxies, none of which directly measures the battery.

China published the missing piece in August. GB/T 46991.1-2025, developed under the Ministry of Industry and Information Technology and the Standardisation Administration of China, sets accuracy and durability requirements for battery health displays in light passenger EVs. It defines State of Available Energy — SOCE, the ratio of a battery's current available energy to that of a new one — and caps the deviation between the dashboard reading and the physically measured value at 5 per cent. Energy burned while parked or running accessories must be converted into an equivalent "Virtual Mileage", accurate to within 3 per cent.

It also sets durability benchmarks: at least 82 per cent SOCE at five years and 100,000 km, 75 per cent at eight years and 160,000 km, 70 per cent at ten years and 200,000 km. On a 100 kWh pack, that is 82 kWh still available at the five-year mark.

The catch is that it is a recommended standard, not a mandatory safety regulation, with no published penalties or recall powers. Whether it changes anything depends on automakers, testing organisations and dealers choosing to use it.

Chinese carmakers exported more than 2.5 million EVs last year, twice the previous year's total, and Chinese cars now account for 55 per cent of EV sales in markets outside Europe and the United States. Those cars turn five somewhere.

"Exporting the car is the easy part," Bill Russo, founder of the Shanghai advisory firm Automobility, told Rest of World. "Building the ecosystem that supports its second and third owner is much harder."

If you are shopping used, the practical move is unglamorous: get a state-of-health reading before you agree a price, and treat a seller's reluctance to produce one as information. The data says the battery is probably fine. The market just cannot prove it yet.