How Fast Does a Kia EV9 Charge on a Tesla Supercharger?

Charging a Kia EV9 on a Tesla Supercharger is significantly slower than using a dedicated 350-kW DC fast charger, with our test achieving a maximum of 84.3 kW compared to the EV9's 210-kW capability. While access to over 21,500 new chargers is a major benefit for Kia EV owners, the current charging experience removes one of the EV9's greatest strengths: its rapid charging speed. Based on our assessment experience, owners should use Superchargers for convenience or emergency charging, but seek out high-power stations for the fastest road-trip charging.

Why is Tesla Supercharger Speed Slower for the Kia EV9?

The primary reason for the slower charging speed is a voltage incompatibility. The Kia EV9 utilizes an 800-volt charging architecture, which is designed for ultra-fast charging on compatible high-power stations. Current Tesla Superchargers (predominantly V3 models) are optimized for Tesla's lower-voltage platforms and cannot fully leverage the EV9's advanced system.

In our test using a NACS-to-CCS adapter (North American Charging Standard to Combined Charging System), the maximum charging power observed was 84.3 kW. This occurred even after using the EV9's battery preconditioning mode to optimize temperature and starting from a low 12% state of charge. A Kia spokesperson indicated that consumers should expect around 100 kW in ideal conditions, which is still less than half of the EV9's maximum capability.

The table below compares the charging performance from our test.

What Do You Need to Know Before Using a Supercharger?

Before plugging in, Kia EV owners should be aware of several key factors to ensure a smooth experience and protect their vehicle's warranty.

• Use a Kia-Approved Adapter: To maintain your vehicle's warranty, it is crucial to use an official Kia-approved NACS-to-CCS adapter. Using a third-party adapter, even a UL-certified one like the Lectron Vortex we tested, may void warranty coverage for any related repairs. Owners who took delivery of a new 2024 or 2025 EV9 or 2024 EV6 from September 4, 2024, or later may receive a free adapter from Kia.
• Pay via the Kia App: While we used the Tesla app for this test, the official method is through the Kia Access app. This integration is expected to streamline the process, as our initial connection via the Tesla app was clunky and prone to "handshake" errors.
• Costs Are Comparable: The cost to charge is similar to other networks. In our area, Tesla Superchargers cost $0.46 per kilowatt-hour, compared to $0.48 per kWh at Electrify America. Pricing varies by location.

When Will Supercharger Charging Get Faster for the Kia EV9?

Faster charging speeds on the Tesla network are contingent on the full rollout of Tesla's next-generation hardware. The 500-kW V4 Supercharger, with its 1,000-volt-capable power cabinets, is needed to fully utilize the EV9's 800-volt architecture.

As of late 2024, these powerful cabinets were in the permitting phase. A Kia spokesperson stated, "When Tesla upgrades to the V4 power cabinets, we anticipate EV9 owners will have the same experience as other 800-volt stations such as the Ionna network." This future upgrade will be a game-changer, making the vast Supercharger network a true high-speed option for 800-volt EVs like the EV6 and EV9.

Should You Use a Tesla Supercharger for Your Kia EV?

The answer depends entirely on your charging needs. The expansion of available chargers is a net positive, but the current speed limitations require a strategic approach.

• For Road Trips: Stick to High-Power Networks. If your goal is to minimize charging stops on a long journey, Kia EV6 and EV9 owners should prioritize DC fast chargers that can deliver high power, such as Electrify America, EVgo, ChargePoint, or the future Ionna network.
• For Convenience and Emergencies: Superchargers Are a Welcome Backup. The Tesla network's reliability and extensive coverage make it an excellent option for urban charging, when other stations are busy, or in an emergency. For Kia Niro EV owners, whose vehicle maxes out at 85 kW, the Supercharger network is now a fantastic addition with no performance trade-off.

Ultimately, the key takeaway is that while Tesla Supercharger access adds tremendous convenience, Kia EV9 and EV6 owners should not expect super-fast charging speeds until V4 hardware is widely available. For now, use the expanded network for flexibility, but rely on 350-kW capable chargers for the quickest top-ups.