Hyundai has rapidly emerged as a frontrunner in the electric vehicle revolution, particularly renowned for its Hyundai EVs‘ exceptional fast charging capabilities. This technological edge has cemented the South Korean automaker’s status as an automotive tech leader in America. Models like the Ioniq 5 crossover have captured significant consumer interest, becoming highly sought-after EVs. However, a significant challenge looms as Hyundai vehicles, including the upcoming Ioniq 9 SUV, begin to access Tesla’s expansive Supercharger network.
The crux of the issue lies in charging speed. While Hyundai’s advanced 800-volt architecture allows for incredibly quick charging on compatible stations, the current Tesla Supercharger network, predominantly operating at around 400 volts, cannot match these speeds for Hyundai vehicles. Consider the new Hyundai Ioniq 9, a spacious three-row SUV designed for families. When connected to a high-power 350-kilowatt charger from networks like Electrify America or EVgo, Hyundai estimates a 10% to 80% charge in a mere 24 minutes. In stark contrast, the same charging session at a Tesla Supercharger is projected to take approximately 41 minutes.
This disparity exists even though the 2026 Hyundai Ioniq 9 is among the pioneering non-Tesla vehicles to feature the Tesla-designed North American Charging Standard (NACS) port directly from the factory. While Hyundai drivers now have access to Tesla’s vast network, achieving the advertised ultra-fast charging times will necessitate seeking out other high-voltage charging providers. This situation underscores that the EV industry’s shift towards NACS is still navigating an “awkward phase,” with interoperability and performance nuances yet to be fully ironed out.
| Feature / EV Model | Hyundai Ioniq 9 | Hyundai Ioniq 5 |
|---|---|---|
| Battery Capacity | 110.3 kWh | 63 kWh / 84 kWh options |
| Optimal Charging (e.g., 350kW, 800V DC Fast Charger) | ||
| Est. 10-80% Charge Time | ~24 minutes | ~20 minutes |
| Peak Charging Power | ~237 kW | Up to ~235 kW |
| Tesla Supercharger (Current ~400V Network) | ||
| Est. 10-80% Charge Time | ~41 minutes | ~24-30 minutes |
| Peak Charging Power | ~126 kW | Significantly lower than optimal |
The core of this charging speed discrepancy is voltage. Voltage, often compared to water pressure in a pipe, is the force that propels electrons through a charging system. Hyundai Motor Group’s premier EVs, including the Ioniq 5 and Ioniq 9, are built on an 800-volt electrical architecture. This high-voltage system is key to their rapid charging capabilities, performing optimally with chargers that can supply at least 800 volts, such as those advertising 350 kW or more, and even some 150-kW Electrify America units. Conversely, Tesla vehicles have traditionally used a 400-volt system, and consequently, their Supercharger network is primarily designed for this voltage level, at least for now.
“It’s absolutely a hurdle,” acknowledged Karl Holodnick, engineering manager for propulsion and charging at Hyundai America’s Technical Center, during the Ioniq 9’s press launch. “When Tesla decides to go to their higher-voltage chargers, our vehicles will be able to charge at higher powers there.” To bridge this gap, Hyundai has integrated hardware into its EVs, like the Ioniq 9, that can step up a Supercharger’s 400V supply to the 800V its batteries require. However, this conversion process is inherently less efficient and slower than direct charging from a native 800V station. As a result, the Ioniq 9 can draw significantly more power—peaking at 237 kW—from compatible non-Tesla chargers, enabling its swift 24-minute pit stop. On a Supercharger, its intake is limited to about 126 kW. Holodnick noted that while the Ioniq 9 should reach and sustain this 126 kW rate effectively, the overall charging time is impacted. He emphasized that focusing solely on peak power can be misleading: “It’s the curve, the area under the curve, that we’re trying to optimize in order to reduce the total charge time.”
The popular Hyundai Ioniq 5 experiences a similar situation: it can achieve a 10-80% charge in about 20 minutes on an optimal 800V charger, but this extends to 24-30 minutes at a Tesla Supercharger. The Ioniq 9’s larger 110.3 kWh battery (compared to the Ioniq 5’s 63 kWh and 84 kWh options) naturally means longer Supercharging times, further highlighting the voltage challenge.
This scenario is part of the broader, somewhat messy transition to NACS. Most of the U.S. auto industry is moving from the older, bulkier Combined Charging System (CCS) plug to Tesla’s more compact NACS design. This shift also involves automakers collaborating with Tesla to grant their customers access to the Supercharger network, the nation’s most extensive. However, this transition is fraught with complexities. While companies like GM, Ford, and Rivian have enabled Tesla network access for their users (often via adapters initially), others such as BMW, Honda, and Volkswagen are still in the process. Adapters remain necessary to bridge NACS and CCS systems, and these voltage disparities add another layer of complication.
Hyundai, along with Kia and Genesis, has been proactive, with NACS-equipped models like the Ioniq 5 and Ioniq 9 already available (they also include free adapters for CCS chargers). Many other EVs with 800V or higher architectures are also caught in this transitional phase. The move to higher voltages offers benefits like improved fast charging speeds, better efficiency, enhanced thermal management, and potential weight savings. For instance, the 926V Lucid Gravity, one of America’s fastest-charging EVs (capable of 400 kW and adding 200 miles in under 11 minutes), also features NACS but sees its Supercharger intake capped at 225 kW. The older Lucid Air, despite supporting 300 kW on high-voltage chargers, is limited to just 50 kW at a Supercharger.
Interestingly, Tesla’s own Cybertruck utilizes an 800V battery system, meaning it too is constrained by the current Supercharger infrastructure. Looking ahead, Tesla plans to introduce next-generation 1000V Superchargers later this year. This development, Holodnick believes, signals the direction for the entire charging industry. “The biggest players in the field right now are mostly moving to 800-volt or higher charging systems,” he stated. “My guess is there will be a point in the future where network providers will continue to converge around the higher-power chargers.” This evolution promises a future where EV owners, including those of Hyundai EVs, can expect a consistently fast and convenient charging experience, much like refueling a gasoline car, regardless of the station.
