Effects Of Frequent Fast Charging An electric car’s ability to accept higher charge currents is affected by the battery chemistry. The accepted wisdom in the industry is that faster charging will increase the rate at which an EV’s battery capacity will decline. However, a study conducted by the Idaho National Laboratory (INL) concluded that while an electric car’s battery will deteriorate faster if it’s only power source is Level 3 charging (which is almost never the case) the difference isn’t particularly pronounced.

The INL tested two pairs of Nissan Leaf EVs from the 2012 model year that were driven and charged twice daily. Two were replenished from 240-volt "Level 2" chargers like those used in one's garage, with the other two taken to Level 3 stations. They were each were driven on public reads in the Phoenix, Ariz. area over the course of a year. They were tested under the same conditions, with their climate control systems set at 72 degrees and the same set of drivers piloting all four cars. The vehicles’ battery capacity was tested at 10,000-mile intervals.

After all four test cars had been driven for 50,000 miles, the Level 2 cars had lost around 23 percent of their original battery capacity, while the Level 3 cars were down by around 27 percent. The 2012 Leaf had an average range of 73 miles, which means these numbers represent a difference of around just three miles on a charge.

It should be noted that much of the INL’s testing over the 12-month period was conducted in extremely hot Phoenix weather, which can inherently take its own toll on battery life, as would the deep charging and discharging necessary to keep the relatively short-range 2012 Leaf running.

The takeaway here is that while DC charging may have an effect on an electric car’s battery life, it should be minimal, especially in that it’s not a primary charging source.

https://www.myev.com/research/interesting-finds/is-dc-fast-charging-bad-for-your-electric-car