Electric car battery

Similar to smartphones, electric vehicle batteries also lose some of their performance over time.

One of the reasons for this is metallic compounds that accumulate on the electrode in the lithium (known as dendrites), making it more difficult to build up voltage over time. The loss of active material also leads to a reduction in overall capacity.

Unfavourable conditions, e.g. frequent fast charging at low temperatures, lead to metallic lithium being deposited in the battery, which can significantly reduce its storage capacity in the long term.

The average service life of a battery, i.e. the time until the remaining capacity falls below 70%, is around eight to ten years.

High-performance lithium-ion batteries last at least 1,000 complete charging cycles. This means that with a battery capacity of 60 kWh and an assumed consumption of 20 kWh per 100 km, they will last for at least 300,000 km. In reality, batteries last significantly longer, as the car is not usually driven completely empty and fully charged, but is charged in the middle. This extends the battery life due to the lower load.

How quickly a new battery ages and thus loses value depends on several factors: Driving style, the number of fast charging processes or large temperature fluctuations put a strain on modern batteries.

As the driver of an electric car, you therefore have a significant influence on how long the battery can be used.

The basic rule is:

• The more charging cycles an electric car battery goes through, the closer it gets to the end of its life
• The larger the battery, the longer it lasts, as it requires fewer charging cycles for a certain mileage and is less sensitive at high charging rates (C-rate)
• The battery ages over time due to electrochemical processes, even when stationary, i.e. the older the battery, the less capacity it has, even if the car has never been on the road!
• In addition, the higher the state of charge (SoC) in longer parking situations, the more favourable the ageing of the electric battery.

The more extreme the outside temperature, the faster the battery ages. Try to avoid temperature fluctuations, such as extreme summer heat or winter cold, as far as possible.

• Electric cars and their batteries work best at temperatures between 15 and 25 degrees Celsius
• Park your electric vehicle in a cool place in summer, e.g. in a garage or underground car park
• Also park the vehicle in a garage in winter

The higher the energy requirement, the greater the load on the vehicle battery. This leads to changes inside the battery and the capacity decreases. In addition, the battery discharges faster at maximum speed, which leads to additional charging cycles.

• Drive with foresight: avoid heavy acceleration, especially when the battery is still cold.
• Modern electric vehicles are equipped with assistants that enable a more economical driving style. Drive in eco mode if possible: This is good for your battery and saves money, as charging takes place at longer intervals.

As with vehicles with a combustion engine, the same applies to electric cars: regular and professional maintenance extends the service life. An electric car requires less maintenance than a conventional car, as there are fewer wear parts. Nevertheless, you should have your vehicle checked and serviced by a specialist workshop for electric cars every year or according to the manufacturer's specifications.

When inspecting an electric car, great attention is paid to the maintenance of the battery - the most important and most expensive component.

• Keep to the service intervals to ensure that the technology functions smoothly
• Only take your electric car to a competent workshop with trained and experienced electric mobility personnel for servicing
• Have software updates installed if an update is provided for your vehicle

The greater the difference between the state before and after charging, the more the vehicle battery ages. The ageing of the vehicle battery is favoured if the charging stroke (difference before and after charging) is particularly large. Fast charging therefore shortens the service life of the battery.

Depending on the thermal management, fast charging can lead to very high temperatures in the battery after a while, which can lead to the build-up of metallic lithium on the anode.

How to charge the battery of your electric car correctly:

• If possible, never drive your battery completely empty
• Do not allow the charge level to fall below 10 % too often; a battery charge level of between 10 and 80 % is ideal for daily use
• Park the vehicle with a half-full battery during longer breaks (e.g. holidays)
• Avoid charging the battery to 100 %.
• Avoid frequent fast charging
• Rather charge the vehicle gently overnight
• A wallbox is recommended for charging at home. This prevents the plug or socket from overheating and at the same time gives the battery sufficient time to charge in a relaxed manner.