Findings from 25,000 DEKRA battery tests
Batteries of electric cars are more durable than consumers sometimes fear
- Example: Experience with electric taxi fleet in Munich, Germany
- Used EV market stands and falls with battery state of health
- Patented DEKRA test procedure quickly provides precise results
The batteries of electric cars are more durable than consumers sometimes fear. This is the conclusion drawn by DEKRA experts from more than 25,000 state-of-health tests that have been carried out to date using the patented DEKRA battery test procedure. Even at higher mileages, the vast majority of traction batteries are still in good condition. One example is the Jaguar electric taxis that were put into service in Munich, Germany, in 2018.
Six of the Jaguar I-PACE were tested by DEKRA this year. Having covered between 110,000 and more than 160,000 miles (180,000 to 260,000 kilometers), the state of health of the traction batteries was between 95 and 97 percent. “We charged the vehicles on average about one and a half times a day, and not particularly gently, but always to full capacity, in order to assure the drivers with regard to range. Our experiences with the electric vehicles have been extremely positive,” explains Gregor Beiner, managing director of Munich-based taxi provider mtz. “The batteries have a very, very long service life, and especially with the safety buffers that the manufacturers build in, they retain their capacity for a very long time. That is why we have continued along this path. Today, we have around 70 vehicles in our fleet, a good third of which are electric vehicles from various brands. We want to have electrified our entire fleet by 2029.”
In the used car market, many prospective buyers are still very hesitant when it comes to electric vehicles. “Many people transfer their experiences with smartphone batteries, for example, to the topic of electric mobility. They have experienced a noticeable decrease in battery capacity after just a few years with mobile devices and fear the same effect with electric vehicles,” says Christoph Nolte, Executive Vice President of DEKRA and Head of the Service Division Vehicles. “Our experience with the battery test shows significantly longer periods of use. Overall, the traction batteries are very good. Even at higher mileages, we still find a state of health of over 90 percent in most cases.”
Nevertheless, there are also outliers. Depending on driving style, climate and charging behavior, a traction battery in an electric vehicle can age at different rates. As the most expensive component of the entire vehicle, it has a decisive influence on the value of a used electric car. Therefore, reliable information on the battery's condition is a crucial factor for a functioning used car market.
DEKRA battery test provides precise information at unrivaled speed
The patented DEKRA battery test, offered in many countries, is currently available for around 130 different vehicle models. Within 15 minutes, the procedure precisely states the battery's state of health with a static test and a short acceleration drive of around 150 to 300 feet (50 to 100 meters). This is based on the so-called parameterization of individual vehicle models, in which the battery is loaded and evaluated in new condition during extensive test drives under a wide range of conditions.
“This creates a kind of coordinate plane that our system uses to analyze and evaluate the actual measurements during the test,” explains Christoph Nolte. ”The result is a statement about the battery's condition that no other method on the market offers at the same speed with the same accuracy.”
DEKRA experts are currently working on a further development of the test procedure that does not require any driving at all. The idea is to measure the state of health while the battery is subjected to a short charging process instead of acceleration. “We want to gradually bring this next-generation test procedure to market for various vehicle models over the course of the coming year. Then the whole process will be even easier as it already is today,” says DEKRA expert Nolte. Further information at
https://www.dekra.com/en/battery-test-for-electric-cars/
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For the specific needs of certain customer groups, for whom reading out OEM information on the state of health is sufficient, a DEKRA service doing just that is in the process of being rolled out across Europe.