Tesla slows down charging rates on its Superchargers for vehicles that use a DC fast-connect charge too many times, according to Electrek, which highlighted the situation after a Tesla owner posted on a forum about a recent road trip.
As Electrek notes, the owner’s charging habits are a bit unusual for someone with a Tesla.
The news that a limit has been placed on DC fast-charging has sparked some outrage among Tesla owners in the thread, but to be fair, this particular Tesla owner has been virtually only charging through DC fast-charging, which is not common amongst electric vehicle owners.
He said that he accumulated 6,685.603 kWh of DC fast charges during 245 total charge ups on CHAdeMO only – and he estimates that he used Superchargers on “50 to 60 occasions” on top of that.
That’s definitely atypical charging behavior since most Tesla owners get most of their charges on level 2 charging at home.
But because numerous factors can impact a charging rate—including the temperature of the battery back or the Supercharger—it’s hard to figure out why a maximum charging rate of 120 kW can’t be attained, Electrek reports. The owner, in his post, said he couldn’t get a rate above 90 kW.
After taking his vehicle to a service center, a technician disclosed that, because the vehicle has “seen significant DC fast charging,” it would now have “permanently restricted DC charging speeds.”
Expectedly, this drew some consternation among owners at the Tesla Motor Club forum. But in a statement to Electrek, Tesla said the limitation isn’t meant to discourage frequent use of Superchargers, but to preserve the “best experience” and vehicle range for owners:
The peak charging rate possible in a li-ion cell will slightly decline after a very large number of high-rate charging sessions. This is due to physical and chemical changes inside of the cells. Our fast-charge control technology is designed to keep the battery safe and to preserve the maximum amount of cell capacity (range capability) in all conditions. To maintain safety and retain maximum range, we need to slow down the charge rate when the cells are too cold, when the state of charge is nearly full, and also when the conditions of the cell change gradually with age and usage. This change due to age and usage may increase total Supercharge time by about 5 minutes and less than 1% of our customers experience this.
Last month, Tesla said it plans to double the size of its Supercharger network by the end of the year.