Fast charging is not good for the battery: «Based on our measurements, analyzes and observations, we can only recommend fast charging when it is really necessary», summarizes Nikolaus Mayerhofer, Chief Technology Manager of Aviloo Battery Diagnostics, which developed a specific test for the analysis of the accumulators.
Manufacturers highlight the wear associated with fast systems for full energy in the user manuals, but offer technologies to shorten the time to the charging station to make their models more attractive. The Austrian company Aviloo has “certified” the aging speed of the accumulators by studying the state of health (SOH, State of Health) of those of 160 vehicles of various manufacturers with a mileage between 180,000 and 200,000 kilometres: with rapid charging, the wear is 17.5% higher than that of batteries supplied in the «normal» way.
To study the correlation between the recharging option and the degradation of the accumulator, Aviloo itself also examined vehicles with a lower mileage, between 80,000 and 100,000 kilometres. The result was not too different: “Specifically – informs a note from the company – if a vehicle is exclusively fast charging, the additional aging caused by these fast charging amounts to about 7.5% after 100,000 km, while it is already about 17% after 200,000».
The Austrian company anticipates any criticisms and specifies that “all the vehicles included in the analysis mounted thermal management systems and presented a normal degradation”. That is to say that no anomalies such as cell defects have been detected. “We will continue to monitor the fast charging phenomenon to see how it will affect battery health in the future,” insists the manager of Aviloo.
For a C-segment car, a study by the German Twaice had found in 2020 a difference in residual value of 450 euros after just 3 years of use (45,000 km) based on the “good” or “bad” use of the battery. And since the latter can affect up to half the price, it is a not exactly irrelevant variable, which sooner or later could also end up in the parameters of those who have to resell second-hand cars with zero emissions. The “snail” refueling wastes time, but apparently guarantees more value.
