SOH of a battery in used electric cars

Are you considering buying a used electric car? Then it is very important to not only look at the mileage or the price, but to pay special attention to the SOH of the battery. The battery is the most expensive component of an electric car and plays a central role in the vehicle’s overall performance.

But what exactly does SOH mean, why is it so important when buying a used car and how can you check it? Read on to find out.

What does SOH mean?

SOH stands for state of health, or the “health” of the battery, and is expressed as a percentage. This figure indicates the condition of the battery compared to a brand-new battery. It is influenced by factors such as age, charging cycles, driving habits and temperature, causing the battery’s capacity to gradually decrease.

The SOH reflects this wear. A new battery delivers its full capacity and therefore has an SOH of 100%. Over time, this percentage decreases, on average by less than 2% per year. The range of the car decreases proportionally.

Why is it so important?

For used electric cars, the condition of the battery is often more important than the mileage. Knowing the current state of health instantly gives you a clear picture of both the operational and financial value you can expect from the car:

1. Range
   The lower the SOH, the fewer kilometers you can drive on a full battery. Where a new car might reach 400 km per charge, a battery with an SOH of 80% would give about 320 km.
2. Financial value
   The battery represents a large part of the total value of an electric car. A lower SOH directly affects the purchase price of your used car.
3. Future costs
   When the battery’s state of health is low or drops quickly, revision or replacement may be needed. These are interventions that can easily cost thousands of euros.
4. Warranty and assurance
   Many manufacturers offer battery warranties up to, for example, 70% SOH. Knowing the current percentage tells you whether the car is still under warranty and helps avoid unpleasant surprises.

How can you measure it?

Now that you know what SOH is and why it is so important when buying a used electric car, you are probably wondering how to check the battery’s condition. Fortunately, there are several reliable ways to measure this:

• By having the car read out at a dealer or specialist
• Through an independent battery test
• By performing a full charge and discharge cycle

Since 2026, the state of health is also displayed on the Car-Pass.

Conclusion: the State Of Health is crucial

The state of health of the battery is perhaps the most important piece of information when buying a used electric car. It gives you insight into the range, value of the car and potential future costs. A battery with a good SOH ensures reliable performance, while a poor SOH can lead to high expenses. So always ask for an official SOH report before buying a used electric car.