Graph of EV battery residual value loss over lifecycle stages: First-Life, Second-Life, and Recycling.

Last year, I leased an electric vehicle (EV) for the first time: a Polestar 2. It’s incredible; I wouldn’t even consider any other type of car in future.

I don’t have to worry about how long the physical batteries will last, but it’s something that EV skeptics, conspiracy theorists, and fossil fuel lobbyists tend to focus on. That’s why it’s good to see the management consultancy P3 conducting a study to counter some EV battery myths.

Scatter plot showing SoH of EV batteries versus mileage with Aviloo and P3 data points and trend lines.

The term ‘state of health’ or SoH doesn’t have a standard definition, so it’s just used in this context to refer to EV battery capacity. The findings? Basically that EV batteries last way longer than was assumed. And, given that they can have a second and even third life after being removed from a car, there’s really no reason not to switch to an EV, pronto.

The field data suggests that the actual battery capacity is maintained longer than assumed under real-life conditions, especially with the often-cited high mileages of 200,000 kilometres and more. Based on the cell lab tests, the SoH model published by P3 in 2023 gave a much more pessimistic forecast for battery health. Up to around 50,000 kilometres, the laboratory model and the field data are roughly the same – above 100,000 kilometres. However, the trend lines diverge significantly. P3 concludes that the actual user-profiles and the control of the cells by the battery management system in the field significantly reduce ageing.

But how can the observed variation be explained? After all, some vehicles still have an extremely high SoH after more than 50,000 kilometres, while individual vehicles are still at 98 per cent after almost 200,000 kilometres – while others quickly fall below 90 per cent. In fact, the charging and usage behaviour of drivers and the vehicles themselves influence this, as do the manufacturers. On the one hand, the intended buffer (i.e., the difference between gross and net capacity) plays an important role in terms of size and utilisation of the buffer. That is because it can be used, for example, to reduce the noticeable ageing during the warranty period – by releasing a little more net capacity over time. On the other hand, the charging behaviour can be adjusted via a software update. On the one hand, this can be a higher charging power for shorter charging times, which leads to more stress in the cell. On the other hand, it is also possible that an update improves the control of the cells, for example, by optimising preconditioning to reduce stress during fast charging under sub-optimal conditions.

Source: electrive