The used-car market for electric vehicles is growing fast, and with it the most important question before buying: how healthy is the battery? With a petrol car, a glance at the mileage and the service book tells you a great deal about its condition. With an EV, by contrast, the battery determines range, charging behaviour and resale value. It is one of the most expensive components in the vehicle, yet it ages quietly and cannot be seen or heard from the outside. Modern traction batteries hold up far better than their reputation suggests. If you want to buy a used EV, what you need most of all is reliable information about the battery’s condition.
This guide shows you which figure really matters, how to have the battery’s condition checked, what a battery certificate offers and what to watch out for when it comes to warranty and charging behaviour. If you are unsure, we always recommend consulting a professional before any decisions are made.
The high-voltage battery is the heart of every electric car and, according to the ADAC, one of its most expensive components. It determines how far you can travel, how quickly you can charge and what the vehicle will still be worth in a few years. Unlike a combustion engine, a failing battery does not announce itself through noises or oil loss. It simply loses capacity slowly, and that is precisely what buyers cannot see from the outside.
Even so, there is no need for undue fear of a used EV. An analysis by TÜV Nord and Carly, covering around 50,000 measurements, shows that most batteries are more robust than expected: the average was around 96 points, and only just under 10% of vehicles came in below an SoH of 85. The important thing is to interpret wear correctly. It does not progress evenly: over the first 90,000 kilometres or so it is slow, and after that noticeably faster.
The central measure is called State of Health, or SoH for short. The figure indicates, as a percentage, how much of the original capacity is still available. An SoH of 100% corresponds to as-new condition, while a lower value means less usable range.
As a rough guide, the industry has settled on the following classification:
A single SoH value says little on its own. It only becomes meaningful in relation to age, mileage and comparable models. For context: according to a TÜV Nord evaluation from spring 2026, many young Volkswagen Group models such as the VW ID.3, VW ID.4, Skoda Enyaq or CUPRA Born still sit at around 92 to 96% residual capacity after three to four years. So if you want to buy a used EV and opt for a young model, you will in many cases have a very solid battery in front of you.
A battery certificate is the written proof of the battery’s state of health. When you buy a used EV, it makes the SoH value transparent and comparable, gives you certainty and creates room for negotiation if the figure turns out lower than expected. Especially when buying privately, where statutory warranty rights are usually excluded in the contract, an independent certificate is often the only reliable basis.
In Germany, several neutral bodies offer testing, including the ADAC in cooperation with AVILOO, as well as TÜV Nord, TÜV Süd, DEKRA and GTÜ. Broadly, there are three approaches:
Costs range, depending on the provider and method, from an inexpensive self-measurement using an adapter to around 150 euros for a detailed written certificate. One point for context: as yet there is no uniformly standardised SoH method. Different providers use different measurement and reference values, so results cannot always be compared one to one. An independent check, not commissioned by the seller, provides the greatest clarity here.
If you want to buy a used EV, you should look not only at the current condition but also at the manufacturer’s battery warranty. The market standard for most brands is 8 years or 160,000 kilometres, whichever comes first. Within that period, manufacturers generally guarantee that the residual capacity will not fall below 70%. If it drops below that, they repair or replace the battery.
Some brands go further. Mercedes offers 10 years or 250,000 kilometres on certain models such as the EQS and EQE, Tesla stages the mileage limit between 160,000 and 240,000 kilometres depending on the model, and Toyota and Lexus reach up to 10 years or very high mileages on some models. Always check the conditions on a model-by-model basis.
Three points are decisive when buying used:
This matters because a battery replacement outside the warranty can cost several thousand euros depending on the model. With a young used vehicle, however, this risk is low, as there is often plenty of warranty left.
The market is becoming more transparent step by step. Under the Euro 7 emissions standard, newly type-approved models are to display their battery condition directly in the vehicle and make it readable via the diagnostic interface. The start is scheduled for new type approvals on 29 November 2026, and for all new registrations expected from 29 November 2027. In parallel, the EU Battery Regulation introduces the digital battery passport, which is to apply from 18 February 2027 for new traction batteries above 2 kWh and makes data such as condition, origin and materials accessible via a QR code.
These dates are set out in regulation but may still shift in detail. For you as the buyer, the direction is what counts above all: the battery’s condition is finally becoming comparable. Until these standards apply across the board, an independent SoH test remains the safest way to prove the condition.
How you charge influences how the battery ages. The ADAC and many experts recommend keeping the charge level between 20% and 80% in everyday use, only charging to 100% when needed, and not leaving the vehicle in direct sunlight for long periods in high heat. Frequent DC fast charging puts slightly more strain on the cells than slower AC charging.
The mix is what matters. If you charge mainly at home or at work and use fast chargers selectively when you are out and about, you protect the battery. Modern battery management systems actively regulate temperature and charging power, so occasional fast charging is not a problem for service life.
Discover JOLT: as a charge point operator, we bring ultra-fast charging to where you need it in everyday life, right in the city centre. Our charging stations offer up to 320 kW charging power and add approximately 200 km of range in around 10 minutes. This is made possible by integrated battery storage enabling ultra-fast charging without costly grid extension. And because our sites are available 24/7, you top up exactly when it suits your day.
Buying a used EV is a rational decision today, provided you keep an eye on the battery. The SoH value shows the condition, a battery certificate makes it reliable, and the battery warranty gives you extra security. Have the battery’s condition checked with an independent test, consult experts if you are unsure, and pay attention to warranty and service history. That way, a perceived risk becomes a safe choice. And regularly charging with JOLT keeps your battery on a good way.
Find a JOLT charging station near you now and charge ultra-fast!
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