By now, the Tesla Supercharger network has provided a superb case study showing the importance of a comprehensive nationwide network of DC fast-charging sites to make electric cars practical for long-distance trips.
While the competing CHAdeMO and Combined Charging System (CCS) standards are presently limited to 50 kilowatts, Superchargers operated at up to 125 kw.
Now, Tesla Motors has quietly boosted its DC charging rate even higher—allowing it to claim hands-down that it currently has the fastest electric-car charging system in the world.
We first learned how this plays out for owners via a quick note from the Massachusetts owner of a Tesla Model S 90D, who wrote:
I supercharged my car this weekend and compared the rate of charge to the last time I tracked the charging power vs. state of charge. It was charging 70 percent faster at the start and 50 percent faster at the end of [a] relatively short Supercharger stop this weekend.
This is a really amazing difference [and] other people are seeing the same thing. It appears that [Tesla has] decided to increase the charging rate now that they have more data.
Charging rates for Tesla Model S 90D at Supercharger sites, Nov 2015 vs May 2016 and Jul 2016
I am only hearing about this change with 90D battery packs so far. A buddy of mine in Connecticut with a P90D sent me his data and he is now charging at about the same rate I am.
To reinforce the point, the owner included a small graph showing the differences in charging time and rates.
While the rate approached 100 kw with a pack already at more than 60 percent capacity, he didn't get close to the 145-kw rate.
Still, it appears that quiet upgrades to the Supercharger system allow at least certain Tesla battery packs to charge more quickly.
A post on Electrek earlier this week provided more details on the upgrade, noting that Tesla had been involved in a spat with U.K. energy provider Ecotricity over the accuracy of its claims to have the fastest electric-car charging system in the world.
The British company took Tesla before the U.K. Advertising Standards Authority, claiming that other networks offered a theoretical capacity of up to 180 kw.
Tesla Motors Supercharger network in the U.S. - projected 2016 installations
The authority ultimately ruled that while that may have been the case, Tesla's quiet upgrade to 145 kw meant that the 90-kwh versions of its Model S and Model X vehicles could use most of that capability to charge faster than any other electric vehicles now on the roads.
That is, Tesla could deliver the highest rate to actual cars in real-life use.
Tesla provided the authority with detailed information showing that its system could theoretically deliver 145 kw, though the company noted that at present, its most advanced battery packs were limited to a charging rate of 120 kw.
And the owner's actual experience charging his Model S 90D appears to confirm that a 120-kw rate is now available at Supercharger sites.
As Electrek notes, an experimental liquid-cooled charging cable being tested at the Supercharger site in Mountain View, California, may enable considerably higher rates yet.