As more EVs are built with the North American Charging System (NACS) port, the charging convenience that was once a main selling point for any Tesla is opening up to more vehicles. NACS, designed by Tesla and for years exclusive to that automaker, is innovative, user-friendly, and capable.

More important, a NACS port allows non-Tesla EVs to use some 20,000 Tesla Superchargers that are part of the largest and most reliable public fast-charging network. Hopefully, it’ll make clunkier plugs like CHAdeMO, J1772, and CCS history.

But at this moment of transition, Supercharging a non-Tesla EV isn’t necessarily the fastest way to charge. For a vehicle like the the 2025 Hyundai Ioniq 5, it’s quicker to use an adapter to plug this NACS-equipped car into the CCS plug commonly found at other DC fast-charging stations. Doing so, we saw a maximum charging rate of 266 kW versus 126 kW using NACS and a Supercharger.

For this test, MotorTrend charged the 2025 Hyundai Ioniq 5—newly equipped with a NACS port—at both a 325-kW Tesla V4 Supercharger and a 350-kW Electrify America charger. The results reveal new layers of complexity in EV charging that may end up frustrating EV drivers before it makes life easier.

Tesla Supercharger vs. Electrify America

MotorTrend‘s real-world fast-charging test zaps an EV’s battery from 5 to 100 percent and reports the results on how much range has been added for 70-mph highway driving. After 15 minutes of charging, the Supercharger pumped 90 miles’ worth of electricity into the Ioniq 5. The Electrify America station delivered 152 miles in the same period.

We’ve traditionally tested non-Tesla EVs at Electrify America stations, as they represent the second most common fast chargers, behind Tesla’s units. It made more sense to us—as it will to most owners, we assume—to plug the Ioniq 5 and its new charging port into a Supercharger capable of delivering well in excess of the Hyundai’s claimed 250-kW peak charging power.

Unfortunately, any owner doing that is likely to be disappointed. The power plateaued at 126 kW from 5 to 73 percent in our test, and a Hyundai spokesperson confirmed that MotorTrend’s Supercharger experience matched what customers should expect. (We’ll explain the why in greater detail below.)

To test the Ioniq 5’s true charging capability, we pivoted back to an Electrify America station using a NACS-to-CCS adapter. The difference means that, in the time it takes to use the bathroom and grab a snack, someone using the Electrify America station has enough additional energy to drive for an extra 51 minutes compared to the Supercharger user. Staying plugged in for longer brought the state of charge closer to parity, but EV road tripping goes faster when you make shorter and more frequent stops.

These differences call into question why you’d even bother to use your non-Tesla EV at a Supercharger. As the 2025 Ioniq 5 demonstrates, going elsewhere will be quicker and more effective with certain EVs.

What? Why? How? It’s Complicated

The auto industry typically talks about fast charging in terms of kilowatts (kW), a measure of power. Before the Supercharger network opened to a wider audience, EV drivers generally just needed to know that if the power number on the charger was equal to or larger than what their vehicle could accept, they could expect the full juice. In theory, at least. Reliability issues and battery preconditioning nuances often prevent this in reality. But the idea was easy enough to understand: Plug a 240-kW 2024 Ioniq 5 into a 350-kW Electrify America station, and you should get 240 kW.

In the new era, EV drivers also need to understand how much voltage a fast-charging station can deliver—a number that isn’t widely advertised by charging providers. Tesla’s newest V4 Superchargers, which are fed by older V3 power cabinets, can only output up to 500 volts, while every other 350-kW charger can deliver 1,000 volts.

The 2025 Ioniq 5’s larger battery pack operates at 697 volts (though it’s often referred to as an 800-volt electrical architecture), and one of the principles of charging a battery is that the power input needs to be higher than the pack voltage or else the electricity moves in the wrong direction: out of the battery pack.

The fact that a 697-volt Hyundai can charge at all on a 500-volt Tesla Supercharger is a tiny feat of modern engineering. Plugged into a Supercharger, the Ioniq 5 sends electricity through its motor windings to step up the voltage before delivering it to the battery pack. That process has a maximum power limit of 126 kW, as we observed.

Give it time, and this confusion should—hopefully—fix itself. Tesla has announced that 1,000-volt Superchargers are coming to North America this year, but the timeline for when and how quickly they’ll roll out is as certain as any other timeline thecompanyhaseverindicated. Other charging providers such as EVgo and Ionna are also opening new dispensers with NACS connectors that can hit 1,000 volts.

Supercharging Could Still Be Faster

There’s still real potential that using a Supercharger for your NACS-equipped EV could be faster when you account for all the variables aside from time spent plugged in.

Anyone who’s road tripped a non-Tesla EV in recent years has charging horror stories. Long lines, broken equipment, slow connections, and human error can all cause infuriating delays. I will never forget the time MotorTrend’s long-term 2023 Ioniq 5 demonstrated its great charging capability by going from 5 to 80 percent in about 20 minutes on a 350-kW Electrify America plug—after a two-hour wait behind a pile of other EV drivers.

Meanwhile, Tesla Superchargers are common, nearly foolproof in their operation, have a reputation for reliability, and typically have abundant plugs available. According to recent U.S. Department of Energy data, Tesla has more than 2,500 Supercharger stations across the country, comprising nearly 30,000 individual plugs between them (some older stations aren’t open to non-Tesla EVs). Electrify America says it has fewer than 1,200 stations with fewer than 5,000 plugs.

With this, Tesla offers easy EV charging instead of the chaotic ambiguity of other networks, even if the actual charging is slower and takes longer.

It’s All Good News

The good news is that buyers of new EVs with built-in NACS now have more options than ever—the choice is yours to decide what’s the timeliest approach. For now, Ioniq 5 buyers will probably want to keep a CCS to NACS adapter in the car. But as NACS becomes the standard across EVs and the public charging stations, we see a future where that adapter won’t be needed anymore.