The battery: condition, lifespan, risk
Registration figures from the original auto-schweiz Excel files, analysed by us. As of 2026-08-31.
This page is the reading version. Calculators, filters and charts on this topic are on the home page, in the section of the same name. To the section on the home page →
The battery: condition, lifespan, risk
The battery is the most expensive part of the car and the most common worry when buying. What its condition is, how you measure it, which value is good — and what the figures on lifespan and fire risk say.
- A typical electric car still has 94 per cent of its battery capacity after 5 to 6 years — measured across 677 tests from Swiss garages, not estimated.
- The odometer says less about the condition than the charging behaviour. A measured value is a bargaining argument, an estimated one is not.
- The chemistry decides the charging rule: LFP should be charged full, NMC should not. Without knowing it, you read the charging history wrong.
Checking the battery: how it actually works
The battery is the most expensive part of the car. A replacement costs up to around CHF 15’000 depending on size. Its condition is called State of Health, SoH for short, as a percentage of the original capacity. 90 percent means: of 60 kWh, 54 are usable.
The odometer says little about it. Two cars with 80’000 km can be 15 percentage points apart, depending on charging behaviour. So measure it.
The measured values, class by class
How capacity is distributed across age and mileage, with the median and spread per class and the difference between the two test methods, is on the data page Battery condition of used electric cars. The basis is 677 tests by the Swiss Automotive Trade Association (AGVS) from its member workshops, 03.2026–07.2026.
Three ways to find out the SoH
| Route | Cost | What it is worth |
|---|---|---|
| The car’s own menu depends on the model, sometimes hidden | free | Some models show the capacity in the service menu. Quickly done, but the manufacturer’s figure is flattering and on many brands cannot be called up at all. Usable as a first indication, not as a basis for negotiation. |
| OBD adapter plus app for people who work on cars themselves | CHF 30–60 | Plug the adapter into the diagnostic socket under the steering wheel and read it out with an app on your phone. It delivers raw values from the battery management system. It assumes you know which app fits which brand and that you can place the values. |
| Independent certificate TCS or Aviloo directly | from CHF 75 | The TCS offers the Aviloo Flash Test: 22 minutes through the diagnostic socket, the result as a certificate. Reckon on around CHF 75. If you want it more precise, take the full Aviloo test: the device comes by post, you run the car down from 100 to under 10 percent, and the certificate arrives by email two working days later. From around EUR 99, TÜV-certified, and it also identifies faulty individual cells. |
Sources: EnergieSchweiz (TCS battery test, Aviloo Flash Test), Aviloo. Prices as stated by the respective provider; check before booking.
Which value is good, which is bad
- Above 90 percent on a three- to four-year-old car: normal, no issue.
- 85 to 90 percent: also within range, particularly at higher mileage. Recalculate the real range and check whether it still covers your longest trip.
- Below 80 percent on a car under five years old: ask questions. Either it was fast-charged hard, or there is a fault. That belongs in the price.
- Below 70 percent: this is where the battery warranty applies with most manufacturers. Ten of the fifteen brands whose Swiss terms we could document name eight years, 160’000 kilometres and exactly those 70 percent. Five name no capacity threshold. Brand by brand it is in the blog post “Eight years, 70 per cent”.
Aviloo reports that most batteries still hold above 80 percent beyond 200’000 kilometres. It usually outlives the car.
A second Swiss source supports this finding: sestorec, the recycling cooperative co-funded by the vehicle importers, now reckons on a battery life of 15 to 20 years — roughly a whole car life. And even after that the traction battery is usually still functional; only the range drops off.
What to do with the result
A measured SoH is an argument on price. Ten percent less capacity means ten percent less range, and that is usually not reflected in the used price. If a seller offers a current certificate unprompted, that is a good sign.
LFP or NMC: the chemistry changes the charging rule
The widespread rule “never charge to full” only applies to some cars. There are two battery chemistries, and they want almost the opposite of one another.
- NMC/NCA (nickel-based): charge to 80 percent day to day, 100 percent only before long trips and then set off soon after. Permanently full and warm ages the cell noticeably faster. Usually found in the long-range and performance versions.
- LFP (lithium iron phosphate): may and should be charged to 100 percent regularly. For its LFP cars Tesla specifies 100 percent and a full charge once a week — because otherwise the flat voltage curve ruins the state-of-charge display for the battery management system. Found above all in the cheaper base and standard versions.
Why this matters when buying used: the same charging history means the opposite depending on the chemistry. Charged to full daily is normal on LFP and a mark against the car on NMC. If you do not know the chemistry, you read the history wrongly.
How to find out: in the car’s menu or the manufacturer app under “battery”, on the data sheet for the version, or via the VIN. Rule of thumb: if the car itself tells you to charge to 100 percent, it is LFP. Common LFP models here are the base versions of the Tesla Model 3 and Y, all BYD models, the entry-level MG4, and the Volvo EX30 Single Motor — the more powerful versions often run NMC. Because this changes with the version and model year, check on the individual car.
For both: heat plus a full battery is the biggest driver of ageing, and frequent fast charging is harder on the cell than the charge level alone.
Sources: manufacturer statements from Tesla (LFP charge limit 100 %, weekly full charge) and Ford (LFP 100 % for calibration, NMC 90 % day to day), Volvo on the EX30 chemistry; on the faster ageing of nickel-based cells at a high charge level and in heat, a study in Frontiers in Energy Research (2023).
What to ask and take with you when viewing
- Where was it charged? At home on a wallbox or out on public chargers. Anyone answering evasively usually charged out on the road.
- How full was it charged? On an NMC car a permanent 100 percent is harder on the battery than 80; on LFP daily full charging is normal and often specified (see “LFP or NMC” above). On many cars the set charge limit can be checked in the menu.
- Service book and recalls. Are all service intervals recorded, are open recalls closed? Software versions matter more on electric cars than on combustion cars.
- Is a battery certificate already included? If so, check the date. A two-year-old certificate describes a different condition. EnergieSchweiz advises asking for one from 50’000 kilometres or three years of vehicle age onwards, before you sign the purchase contract. If none is included, you can arrange a test yourself — with whom, at what price and whether you do it yourself is in the blog under “Where to have the battery checked”.
- Are both charging cables included? Type 2 for the wallbox and public chargers, plus the emergency cable for a household socket. If they are missing, replacing them quickly costs several hundred francs.
- When does the battery warranty expire? Date of first registration plus eight years, and hold the odometer reading against the warranty limit. Whichever comes first counts.
- Ask for a test drive over a full day. Many garages allow it. That way you see the real consumption instead of the figure in the brochure.
Checklist based on the used-car recommendations from EnergieSchweiz, extended by the points on charging behaviour and the warranty period.
Fire risk: what the figures say
The worry is understandable. A lithium-ion battery in thermal runaway is hard to extinguish. The statistics point the other way.
- The Allianz Center for Technology analysed claims data from 2020 to 2024. Less than one percent of all reported vehicle fires involved battery electric vehicles.
- Norway: electric cars accounted for 2,3 percent of vehicle fires with a fleet share of 8,9 percent.
- The German insurers’ association GDV finds no indication of a higher fire risk in motor insurers’ data.
- All high-voltage vehicles in Europe must meet the ECE R100 standard, with tests for heat resistance, impact protection and short-circuit safety.
One distortion belongs in the picture: electric cars are on average younger than the fleet, and young cars burn less often. The order of magnitude nevertheless remains clear.
What is different in a fire
Rarer does not mean more harmless. When a battery burns, the response differs considerably:
- The fire service needs around ten times the volume of water compared with a burning combustion car.
- Extinguishing is often done with a piercing lance that directs the water straight into the battery casing.
- It is not over once the fire is out. The vehicle is monitored for 24 to 48 hours or placed in a quarantine container, because cells can reignite.
- One advantage for the rescue services: no flammable fuel runs out, and the fire spreads beyond the vehicle less often.
What you can influence yourself
- Pay attention to the cell type. Lithium iron phosphate is regarded as thermally more stable than nickel-based cells, but has a lower energy density. Nickel cells have dominated in Europe so far. LFP is found among others in the Renault Twingo, in the base version of the VW ID.Polo and in many BYD models.
- Do not leave it standing full. A car parked at 100 percent for days ages faster, especially in the heat — that applies to both chemistries. The right daily charge level, by contrast, depends on the cell type (see “LFP or NMC” above). This is why electric cars are only partly charged during transport.
- Carry a rescue sheet behind the sun visor. It shows the fire service where the disconnection points are.
- In an emergency: call the fire service and say explicitly that it is an electric vehicle. Do not attempt to extinguish it yourself with a hand-held extinguisher.
Sources: Allianz Center for Technology (2020 to 2024), GDV, Norwegian fire statistics via t-online, AUTO BILD, ingenieur.de. No Swiss survey of vehicle fires by drivetrain was found.
And at the end of the battery’s life?
The widespread worry that the battery ends up as hazardous waste does not hold. Two plants process them in Switzerland: Batrec in Wimmis and Librec in Biberist SO, opened in April 2025 and designed for 9’000 tonnes a year when fully built out. The recovery rate is above 90 percent, and by Librec’s own account 97 percent — cobalt, nickel, lithium and copper go back into the material cycle. Around 165’000 tonnes of lithium-ion batteries were in circulation in Switzerland at the end of September 2025.
Source: auto-schweiz annual report 2025 (May 2026), figures from the recycling cooperative sestorec and from Librec AG.
What a field-sales or fleet vehicle means
Field-sales cars cover a lot of motorway and charge at high power daily. That drives ageing. The Geotab analysis of over 22’700 vehicles gives 2,3 percent capacity loss per year and names charging power as the strongest factor, not age or kilometres.
Fleet vehicles are often cheaper, serviced without gaps and have a traceable history. The battery test is nevertheless mandatory there, and the measured value belongs in the price negotiation.
Further
When a used car pays off is under Used or new. How charging power and location drive the cost, under Charging. And what a car costs over the holding period is calculated by Total cost.
