Silver Power Systems (SPS), battery analysis company have early findings that show EV battery life degrades faster than previously expected. This was especially present in the BMW i3 they tested which may make our dreams of a used i3 as a city car go out the window. And what about the electric MINI Cooper SE and any future battery degradation?

First seen in Autocar, the study shows that there are wide variations in performance, especially within fleets of the same vehicles. SPS found that a 2015 BMW i3 with 33,000 miles had seen major reduction in range. In total the 22 kWh battery pack had degraded by 19%. Its owner claimed that on a full charge and in Eco Pro mode, the car had a driving range in summer of 85 miles.

Other models fairs differently. 2014 Nissan Leafs tested showed a 23% degradation after almost six years while a 2015 Tesla Model S saw 10% degradation. 

It’s worth noting that some dealers are skeptical of SPS’s methods in testing these batteries. One EV specialist told autocrat that “A warm battery will give a good figure, so sellers run the car first then check it,” he said. “I’ve seen it happen when dealers are selling to the public as well as to each other. This way, they get a better price for the vehicle. The best thing is to go by the car’s range display. We’ve sold hundreds of EVs, and on this basis, we see 1-2% battery degradation each year.” 

Cooper_SE F56 electric MINI Cooper SE Electric

Autocar then spoke to EMR, a vehicle recycler who works directly with BMW. Interestingly they are coming to a slightly different conclusion.

“EV batteries are lasting far longer than anyone expected,” he said. “Although batteries degrade over time, for third owners and beyond, driving range is less of an issue. The car is probably a second or third vehicle for short trips, and in any case the car is much cheaper than a new one, so they make allowances. “I see EVs easily lasting as long as ICE cars; possibly longer because they’re simpler. It’s going to be 2045, long after sales of ICE vehicles have ceased, before we start seeing end-of-life EVs with seriously depleted batteries in large numbers.”

For our money that’s an important perspective here. The degradation of batteries are inevitable but the reduction of other maintenance costs that electric cars offer should also be factored in. The total cost is something that is still somewhat unknown but there is clearly a massive shift in how owners spend money on EVs versus ICE cars in regards to maintenance. Additionally BMW engineers have told MotoringFile previously that the thermal management is much more advanced in the Cooper SE and we should see less degradation than in the i3.

What do you think? Does battery life degradation scare you in terms of electric MINIs?