How Long Does an EV Battery Really Last? The Honest Numbers
The most common fear before buying an EV sounds like this: "the battery dies in five years, and then I have to buy a whole new car." It is an understandable worry — but it is mostly a myth left over from first-generation EVs. This guide explains, with no sales pitch and no percentage promises, what really happens to a battery over time, how the numbers look on real cars, and why a modern pack is far more durable than people think.
What actually happens to a battery over time
First, a battery does not "die". "Dying" makes you picture a sudden failure, where one morning the car simply won't start. Real life is nothing like that: you get a slow, gradual, predictable loss of capacity. Today you drive 400 km; a few years later, maybe 380. It is not a cliff to fall off.
Second, a battery degrades not by "time" on the calendar but mainly by mileage and the number of charge cycles. A car parked in a garage ages slowly; a car that drives a lot ages faster — but in both cases the rate is measurable and known.
On average, real-world degradation is about 5–10% of capacity per 100,000 km. That means after 100,000 km a typical battery still holds roughly 90–95% of its original range. It is a slice off the top — not half the car.
The math on a real pack: Deepal S07 and Xiaomi SU7 Max
To keep the numbers from being abstract, let's look at two real, in-stock cars. The price always sits beside a named Western rival — compare for yourself:
Take the Deepal S07 with its ~80 kWh CATL battery and a starting range of 475 km (WLTP). At a typical 5–10% degradation per 100,000 km, after that mileage it will still deliver roughly 90–95% — somewhere around 430–450 km. Since most daily trips are 30–60 km, that difference is rarely felt.
Same with the Xiaomi SU7 Max: a 101 kWh CATL battery, 830 km (CLTC) from new. After 100,000 km — still about 90–95%, so nearly 750–790 km of the rated figure. These are large packs, so even a slice off the top leaves a wide buffer.
For a familiar reference point: the Tesla Model 3 (~€42,000) uses the very same CATL/LFP cells, which is exactly why it is so often cited as the benchmark for battery longevity. The Deepal S07 is €35,033 and the SU7 Max is €39,100; all three lean on the same cell factory.
Why LFP chemistry lasts longer than the older NMC packs
Those scary "five years" estimates come from first-generation EVs with older NMC (cobalt) batteries. These cars use LFP (lithium iron phosphate) chemistry, which survives considerably more charge cycles and runs cooler.
LFP also tolerates everyday 100% charging well — unlike the older chemistries you had to "babysit" between 20% and 80%. That is exactly why the industry, Tesla included for its standard cars, moved to LFP. More on safety and fire risk in our LFP guide.
In practice this means less worry: the battery can be safely charged to full, it copes better with heat, and its expected service life is far longer than the batteries people remember from the first EVs.
Who makes the cell matters
Battery quality starts at the cell maker. The Deepal S07 and Xiaomi SU7 Max batteries are made by CATL — the world's largest battery maker, which supplies the very same cells to Tesla, VW and Mercedes EVs too.
That means a "Chinese battery" and "the battery in a European EV" are very often the exact same cell from the exact same factory — only the badge on the hood differs. The expected longevity is the same as any other CATL-equipped car. More on this: our guide on who makes EV batteries.
The safety net you don't pay for: 3 years / 100,000 km
You don't rely on statistics alone. All of these models carry a factory warranty of 3 years / 100,000 km, covering battery underperformance and defects within that window. If capacity drops more than normally expected, that is the maker's problem, not yours.
Service is handled in the EU by the local partner — diagnostics, warranty work and parts are dealt with here, not by shipping the car to China. More on this: our guide to Chinese-EV service and warranty in the EU.
What shortens battery life and how owners avoid it
Three factors speed up degradation: sustained heat, very frequent DC fast-charging, and regularly sitting at the extremes. For LFP packs, 100% every day is fine, but heat and constant fast-charging tire any battery.
In practice: charge slowly at home day to day, save the DC fast chargers mostly for trips, and don't leave the car sitting empty or full for long stretches in heat. These are small habits that make an already-small difference in battery life smaller still.
How to read state-of-health when buying used
If you buy a used EV, one number matters more than any other: state of health (SOH). It shows what percentage of the original capacity is still left. An SOH of 90% after 100,000 km is a good result; a steep drop would be a warning sign.
Ask the seller for the SOH figure, check the charging history (was the car mostly slow-charged or constantly on DC fast chargers), and how much of the warranty is still left. For comparison against a Western car, our Chinese-EV-vs-German article is a useful read.
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Frequently Asked Questions
Does an EV battery really die in 5 years?
No. That is a myth left over from first-generation cars. A modern battery does not degrade by "time" but by mileage and charge cycles, and degradation runs at roughly 5–10% per 100,000 km. After five years of average mileage a battery typically still holds 90%+ of its capacity. "Dying" implies a sudden failure — in real life you get slow, gradual, predictable capacity loss instead.
How much range do you lose per 100,000 km?
On average about 5–10% of capacity per 100,000 km. In practice: if a Xiaomi SU7 Max starts at around 830 km (CLTC), after 100,000 km it can still deliver roughly 90–95% of that. It is a slice off the top, not half the car — and day to day most owners barely notice it.
Is an LFP battery better for long life than the older type?
Yes. LFP (lithium iron phosphate) cells survive considerably more charge cycles than the older NMC (cobalt) batteries people remember from the first EVs. They also tolerate everyday 100% charging well and run cooler. That is exactly why the industry — Tesla included, for its standard cars — moved to LFP. More on this in our LFP-safety guide.
Does the factory warranty cover battery degradation?
Yes. The factory warranty of 3 years / 100,000 km covers battery underperformance and defects within that window. If capacity drops more than normally expected, that is the maker's problem, not yours. It is comparable to a new European car's warranty cover, and service is handled in the EU by the local partner.
How is the Deepal S07 / Xiaomi SU7 Max battery expected to age?
Both use CATL-made cells — the Deepal S07 a ~80 kWh CATL pack, the Xiaomi SU7 Max a 101 kWh CATL pack. At typical ~5–10% degradation per 100,000 km, the Deepal S07 (475 km WLTP from new) and the SU7 Max (830 km CLTC from new) will keep roughly 90–95% of their range after 100,000 km. Because it is the same cell maker that also supplies Western brands, the expected behaviour is the same as any other CATL-equipped car.
What kills an EV battery fastest and how to avoid it?
Three main factors: sustained heat, very frequent DC fast-charging, and regularly sitting at the extremes (0% or 100% on NMC packs). In practice: charge slowly at home day to day, save the DC fast chargers mostly for trips, and avoid leaving the car sitting empty or full for long periods in heat. For LFP packs, 100% every day is fine — they are more resistant to these factors.