Concerned about EV battery degradation? Don’t be


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Get on board and fasten your seat belt, partner – because it’s story time.

My first close encounter with an electric vehicle was back when BMW launched its i3. I remember seeing this car rolling silently across the showroom floor, thinking it was some kind of personal transportation system of the future.

As interested drivers who entered the showroom on vehicle opening night reveal, one question seemed to resonate in space more than any other … “How long will this last?”

Speaking to the esteemed guest group, it became clear that they were actually referring to two things: range and battery life.


When it comes to range, the capacity of your electric vehicle depends on the type of electric vehicle itself and the size of its battery. The bigger and heavier the EV, the shorter its range will be compared to a lighter, more aerodynamically sleek vehicle – assuming both cars have the same size battery.

EV batteries are rated in kWh (kilowatt hours). This is how much electricity they can store, check out this handy explainer to learn more. But as a general rule, the larger the battery, the more range the electric vehicle will have.

There are a growing number of EVs capable of going over 200 miles on a single charge, but when the i3 was launched, 100 miles was the norm.

Software optimization can affect the range of an electric vehicle as well, but not by much. Tesla previously released an over-the-air software update that increased the range of some Model 3s of 9 miles.

Battery degradation

While many of the party’s guests focused on how far the car had traveled, they were also concerned about the battery life before it ran out of service. This phenomenon is known as battery degradation.

As a lithium-ion battery is loaded and unloaded, it degrades. Remember the laptop that lasted all day and is now dead by lunchtime? It’s the same thing, but on a much larger scale.

Many potential EV buyers worry about this happening to their cars. So let’s take a look and see how much we should care about it.

Fortunately, we have a lot more user data than five years ago, and as EVs age, it’s become clear how much charge they can lose.

Some of those most affected by battery degradation are the owners of the first Nissan Leafs, especially those made over seven years ago.

The problem stems from a technical decision made by Nissan for its first-generation Leaf vehicles, where it opted for passive air cooling, rather than active cooling for its batteries. Air cooling is much cheaper to produce but much less efficient at handling battery thermals and can cause greater temperature variations. As a result, early Nissan Leafs are known to suffer from above average battery degradation as they age.

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Credit: Wikimedia – CC