Guide and tips
The battery is the most expensive component in your electric car and is sensitive to incorrect charging and usage habits. By adopting the right charging habits, you can significantly extend the life of your electric car’s battery and maintain its range in the long term. In this guide, you’ll learn which factors accelerate battery ageing and how you can take specific steps to counteract them.
Before we get to the tips on electric car batteries, it’s worth taking a quick look at the technology: if you understand why an electric car battery ages, you can better assess battery degradation and take targeted steps to counteract it in everyday use. Charging behaviour, temperature and usage are among the most important factors influencing the battery’s lifespan and condition.
Electric car batteries age in two different ways:
Both forms of ageing lead to chemical and structural changes within the battery cells. This increases the internal resistance and reduces the battery’s usable capacity.
In practice, this means:
The factors mentioned have a direct impact on the condition of the battery and cause its performance to change over time. To quantify this condition, the so-called State of Health (SoH) is used.
The current condition of a battery is described by what is known as the State of Health (SoH), expressed as a percentage of its original capacity when new. This SoH is often derived from battery data or certificates.
An SoH of 90% means: your battery still has 90% of its original capacity and therefore offers ~90% of its original range.
| SoH value | Condition | Meaning | Recommendation |
| 90–100% | Very good | almost new | no action required |
| 80–89% | good | age-appropriate | Normal operation |
| 70–79% | moderate | noticeably reduced | Discount on purchase |
| < 70% | critical | Heavy wear | Check warranty/service |
This is the most effective single measure you can take. Avoid regularly charging the battery to 100% or letting it run down to below 10%, as both put excessive strain on the cells. In everyday use, a charge level between 20 and 80% is perfectly adequate. Most modern electric cars allow you to set a charge limit directly in the vehicle menu.
Exception:
You can charge the battery to 100% before long journeys; doing so once in a while is unlikely to cause any harm. The only problem is regularly charging the battery to full capacity in everyday use.
If you charge your vehicle overnight, programme the charging process so that the battery is full just before you set off, not hours beforehand. This is because a battery that remains at 100% for hours ages faster than one that is used immediately afterwards. Almost all modern wallboxes and vehicles allow you to schedule charging using a timer.
Lithium-ion batteries charge more efficiently and are less likely to be damaged when they are at operating temperature. This is particularly true in winter: where possible, charge the battery immediately after a journey, rather than waiting for it to cool down for hours. This shortens the charging time, reduces energy loss and protects the cells.
The optimum operating temperature for electric car batteries is between 15 and 25 degrees Celsius. Both extreme summer heat and severe winter cold accelerate the battery’s natural ageing process.
Practical measures: In summer, park the vehicle in the shade or in an underground car park where possible; in winter, park it in a garage if possible or use the app to preheat the vehicle whilst it is still plugged in.
Important in winter:
Pre-heat your vehicle using the plug-in pre-conditioning function. This helps preserve the battery’s life whilst ensuring maximum range right from the start.
High energy consumption puts greater strain on the battery, particularly when the battery is still cold.
Drive with foresight and use Eco mode wherever possible. Regenerative braking (energy recovery during braking), on the other hand, is desirable: it reduces the strain on the brakes and feeds energy back into the battery. The larger your vehicle’s battery, the less impact each individual charging cycle has. This is a structural advantage of modern, larger batteries.
The myth that fast charging (DC) is inherently harmful is not true in general. Recent studies show that moderate fast charging puts hardly any more strain on the battery than normal charging. It only becomes a problem if you rely on fast-charging stations every day in very cold weather and regularly charge from a low charge level to almost 100%.
In everyday life: opt for AC charging at home and reserve fast charging for long journeys.
Good to know:
Frequent, moderate fast charging does little harm to modern batteries. However, fast charging several times a day in extreme temperatures and when the State of Health (SoH) is very low can be damaging.
Your vehicle’s Battery Management System (BMS) continuously optimises charging and discharging strategies. Many manufacturers improve this control system via over-the-air updates, often without the driver even noticing.
You should therefore always keep your vehicle’s software up to date. And: have the vehicle professionally inspected at regular intervals. Because what the BMS doesn’t detect, an external battery check can reveal.
Even the best care can only slow down the ageing of the battery; no one can stop it entirely. If the range of your electric car drops noticeably, this is a warning sign: is it actually down to the battery? Or are other factors such as driving style, temperature or software settings playing a part?
Furthermore, there are situations in which a professional assessment of the battery’s condition is simply essential:
In all these cases, a professional battery check provides the only reliable answer: the State of Health (SoH) is read directly from the vehicle data. No dismantling, no intervention.
Independent SoH analysis via the OBD diagnostic interface. Certified to the European CARA standard. For buying, selling and everyday safety.
That’s not necessarily true. Moderate, occasional fast charging at normal temperatures puts hardly any more strain on modern batteries than AC charging. The real problem lies in daily fast charging in extreme cold or heat, as well as repeatedly charging from a very low to a nearly full charge level.
Wrong. The opposite is true. Deep discharges below 5–10% put a significant strain on lithium-ion cells. Neither electric car batteries nor smartphone batteries benefit from being fully discharged. Regular partial charges (20–80%) are much gentler on the batteries.
Real-world data shows the opposite: electric cars with more than 200,000 kilometres on the clock often still have a State of Health (SoH) of 80–85%. The batteries in modern electric cars are more robust than their reputation suggests, and far more durable than smartphone batteries, which many buyers unconsciously compare them to.
Wrong. Mileage and battery health are hardly reliably correlated. A vehicle with 30,000 km may have a lower SoH than one with 80,000 km if, for example, the former has often been fully charged in extreme temperatures. The only reliable indication is provided by a direct SoH measurement.
Modern electric car batteries last considerably longer than is often assumed. With proper care and normal use, many vehicles still retain 80–85% of their original capacity even after 150,000–200,000 kilometres.
Depending on the manufacturer, a 70% State of Health (SoH) is usually guaranteed for 8 years or up to a defined mileage.
A SoH below 70% may be covered by the warranty, depending on the manufacturer and model. In this case, you may be entitled to a battery replacement at the manufacturer’s expense. Check your vehicle warranty and have the SoH verified by an independent provider such as TÜV NORD.
Charging to 100% every day isn’t ideal, but modern vehicle management systems significantly limit the damage. A better approach is to set the charging limit to 80% and only charge to 100% before long journeys. Many manufacturers explicitly recommend this, and some vehicles actively remind the driver to do so.
Keeping the battery at a charge level of 50–70 % for extended periods is the gentlest option for the battery. Although calendar ageing occurs even when the battery is not in use, maintaining a moderate charge level minimises the strain on the cells.
Leaving the battery fully charged or fully discharged is not advisable.
Depending on the vehicle model and battery size, a battery replacement outside the warranty period costs between €5,000 and €15,000.
A professional battery check is therefore a very sensible investment, both before buying a used car and for regular condition checks.
If you follow the seven tips in this guide, you’ll preserve your battery, get more range and safeguard your vehicle’s value in the long term. But at some point, the question is no longer: “How do I look after my battery?” but rather: “How good is my battery still?”
That is precisely when an independent, professional battery check is the right answer.
