It is well known that batteries lose performance over time and use. We’ve all been through it with phones and laptops; the same goes for electric vehicles (EVs), which will see their maximum potential driving range diminish between charges over the years and miles.
However, different cell chemistries can provide differing performance in this regard. So how quickly will the battery in an EV degrade, and what are the best and worst makes and models when it comes to preserving range over time?
We spoke to GeoTab, an American fleet management company that keep track of battery degradation data of 6,300 pure electric (EV) and plug-in hybrid (PHEV) vehicles worldwide, since 2014.
Not every make and model of EV was included in the data, as the companies that GeoTab provides fleet management for did not run every EV and PHEV model. Some cars also have more data than others, if they have been used for a longer period of time. But before we look at the data and the best and worst performers for battery degradation:
What causes a battery to deteriorate and what can I do to keep it healthy for longer?
No matter how carefully you take care of your electric car’s battery, it will always lose performance over time, even if your mileage is low.
However, there are factors that contribute to battery degradation. dr. Gavin Harper, a critical materials researcher at the University of Birmingham, explains that “not only the number of charge-to-discharge cycles a lithium-ion battery goes through will cause degradation, but also the degree to which that battery is cycled.
“Slow charging extends battery life, but fast charging leads to faster degradation. Temperature control is also important. While colder temperatures temporarily affect battery capacity, producing less power, batteries regain function when they warm up. More long-term damage is caused by having Lithium Ion batteries at too high a temperature.”