Battery degradation is one of the most important topics for EVs, specifically in the case of older cars. Here we can take a look at a first generation Kia Soul EV, recently tested by Bjørn Nyland.
The car is almost 7 years old and covered almost 100,000 km (62,000 miles). Its nominal battery capacity (usable) - when new - was 27 kWh, although after multiple tests, Bjørn Nyland sticks to 26 kWh as a more appropriate/achievable number, in his opinion.
In the US, the original Kia Soul EV had an EPA range of 93 miles (150 km), while its slightly upgraded version, with a 30 kWh battery, was rated at 111 miles (179 km). Let's note that those cars had no liquid cooling for the battery system.
For a few years now, Kia has offered in Europe a completely new generation, with a 64 kWh or 39.2 kWh battery.
Battery degradation test results
The discharge test from about 100% to about 4% state-of-charge (SOC), down to the turtle mode, revealed a range of a bit over 100 km (62 miles) and energy consumption of 163 Wh/km (262 Wh/mile).
According to Bjørn Nyland, it means that the car has available about 17 kWh, which is roughly 65% of the initial net battery capacity.
Battery capacity degradation of 35% or so sounds pretty substantial, especially for a car that is almost 7 years old and covered 100,000 km (62,000 miles). If true, the drop would be about 5% per year, on average.
In the end, some additional fast charging tests revealed that also the charging power is lower compared to a newer car.
Bjørn Nyland wonders whether such a high battery capacity degradation and range reduction will be covered by the warranty, which is still active (for 7 years or 150,000 km). We are eager to see a follow-up episode.
Another question is whether it's a single case or an exception to lose a third of the driving range at that point?
In the video comment section, we have found a few users reporting a substantial battery capacity/range degradation as well. Some got approved for a battery replacement, some already after the replacement operation.
In other words, it's worth double checking the topic when buying a used Kia Soul EV with a 27/30 kWh battery.