For about a decade now, Tesla has led the automotive industry in the rollout of North American fast-charging infrastructure. While most automakers chose to rely on third-party networks like EVgo or Chargepoint for CHAdeMO and CCS infrastructure, Tesla instead chose to build out their own exclusive charging network. They did so using a custom charge protocol now known as the North American Charging Standard (NACS).

The young automaker was able to grow its network quickly and developed a reputation for reliability. Within a few years, the Supercharger network became the brand’s biggest advantage over other automakers.

Kia EV9 Supercharger Woes

The Kia EV9 can reach charge rates of over 200 kW on many Electrify America stations. However, V3 Superchargers are limited by their 400V architecture. This causes issues for EVs that rely on 800V architecture for peak charge speeds.

But these days, competing CHAdeMO and CCS networks have grown rapidly nationwide. Technological advancement has grown as well. It is not uncommon for new CCS installations to be pushing 350 kW, far surpassing the 250 kW capable V3 Superchargers.

So it came as a surprise to many when last year, one by one, automakers began abandoning CCS in favor of Tesla’s NACS. Following these announcements, Tesla began expanding Supercharger access to CCS-equipped vehicles for the first time. While the charging experience has been great for many drivers, it has been a less-than-ideal for others.

Vehicles like the Chevy Silverado EV and the Kia EV9 rely on 800V charging infrastructure to achieve their maximum charge rates. Current V3 Superchargers were built with 400V charging in mind.

This is what Alex from the EV Buyers Guide YouTube channel recently explored. He arrived at a CCS Magic Dock-equipped Supercharger to test out the charge performance of the Kia EV9. The process of initiating a charge could not have been easier. But disappointment sets in once the charge session begins.

While the EV9 can reach rates over 200 kW from a 350 kW Electrify America (EA) station, the V3 Superchargers cannot even get the Kia over the 100 kW threshold. For this charge session, the EV9 peaked at a rate of 84 kW. This is not only less than the car’s max charge rate on a 350 kW CCS station, but also slower than a typical 150 kW CCS station.

Alex confirmed in the comments that the battery had been pre-conditioned before this charge session. He explains that “V3 Superchargers don’t natively put out the voltage required to charge your battery. (…) In order to charge, these EVs have to boost the voltage using an onboard DC-DC conversion circuit that not only reduces charging efficiency, it reduced charging speeds dramatically.”

Alex estimates that the EV9 should be able to hit up to 100 kW from a V3 Supercharger, however. Some Kia drivers have reported charge speeds in the 90 kW – 95 kW range.  

The eventual launch of V4 Superchargers should enable 800V charging at speeds up to 350 kW. But your guess is as good as ours as to when we will see these units at our local Superchargers. While the next-generation charge stations have been spotted in the wild, they have so far been powered by older V3 cabinets. So for the time being, charge speeds will continue to be limited for vehicles that charge at 800V.

What has your experience been so far charging your non-Tesla on the Supercharger network? Let us know in the comments below.