I Tried Tesla Supercharging My 2025 Hyundai Ioniq 5 Limited, and It Only Reached 78kW, Which Dropped to a Much Lower Level as My Battery SOC Approached 80% - Shouldn’t It Be Much Faster?

Over the years, we’ve tested dozens of EVs on multiple different DC chargers. None of them has ever lived up to the "fast charger" hype. We don't see the fast rates that are promised, and we observe much lower kW rates than the automakers and charging companies say are possible. This week, we did another test, and we were again disappointed by the rate of charge.

Then we spotted a post in one of our favorite Facebook vehicle clubs, the Ioniq Guy Group. This is an extremely informative and well-run club, started by a content creator whom we follow closely. The post about slow DC charging we spotted had images and descriptions that matched our own experience precisely. Two different tests, with the same model at the same brand DC charger, but by two separate people. The promises and expectations around DC charging are starting to be debunked on a regular basis.

Our story title paraphrases the owner of a 2025 Hyundai Ioniq 5 Limited. We’ll keep this person’s identity protected and call him AB. Here is exactly what AB said about his Supercharging session in a post:

I decided to give Tesla supercharging another shot tonight on my 2025 Limited. It communicated with the car quickly and took off charging pretty fast.  My starting battery percentage was about 68% and the battery showed it was adequately warm for charging.  It started off and jumped up to about 110 kW, but quickly sank back to 78 or so, and sat there all the way to 82%.  (When it started sinking, I figured the complete shutdown was coming).  At least I didn’t get an interrupted session this time.  But from what I’ve read, it should’ve been charging faster than that.  I’d like to just once go to a Tesla charger and have it behave the way it’s supposed to with this car.   Other people have reported that I should be getting close to 125 kW flat from a low charge level to near 80%.

The Superchargers say that they can provide “250kW max.” We get it. Under ideal circumstances, they can deliver a lot of power. But isn’t a cool summer day, alone at the charger, with a properly preconditioned battery "ideal?" And what about the Ioniq 5 Limited? On its specification page, Hyundai states that the NACS-equipped Ioniq 5's DC Fast Charge rating is 150kW (400V). 

The real question is, why are users only getting half of the rating (or less) that the charging companies and car companies say is the “max rate” when they are charging at SOCs below 70%?

The charging curve is one answer. You see, EVs don’t accept power at a continuous rate as they charge up. At a lower state of battery charge (SOC), they can accept more power than a higher SOC. Manufacturers and DC charging station owners list the most impressive number imaginable. “Max” is the disclaimer. Or “Can.” During charging, the rate at which the power can be absorbed by the battery drops like a rock. In our testing past 80% SOC, we observed rates of around 33 kW. That’s a long way from 240kW.

AB is well aware of this. He said in a follow-up comment in the discussion under the post, “I’m not asking (the car) to do anything that it’s not supposed to be capable of. I fully understand charging curves.” AB also never expected the 240 kW or the 230-350 kW ratings from Tesla and Hyundai to be real. He says, “Getting 75 kW when you’re supposed to be getting around 125 makes the charge station a heck of a lot slower than it is supposed to be.”

Many other owners have observed this less-than-expected charging rate. One owner said, “I've only really ever used EA, but it typically starts slowing down somewhere in the 60-70 percent area, and then to a crawl as it gets to 80.”

We think that one owner nailed the reality of DC charging. He said, “Lower your expectations.”

What’s your take on DC charging? Should owners just accept the fact that the ratings of the chargers and cars seem to be out of touch with the actual charge rates observed in the real world? Tell us your thoughts in the comments section below. 
 

John Goreham is the Vice President of the New England Motor Press Association and an expert vehicle tester. John completed an engineering program with a focus on electric vehicles, followed by two decades of work in high-tech, biopharma, and the automotive supply chain before becoming a news contributor. He is a member of the Society of Automotive Engineers (SAE int). In addition to his eleven years of work at Torque News, John has published thousands of articles and reviews at American news outlets. He is known for offering unfiltered opinions on vehicle topics. You can connect with John on LinkedIn and follow his work on his personal X channel or on our X channel. Please note that stories carrying John's by-line are never AI-generated, but he does employ grammar and punctuation software when proofreading and he also uses image generation tools. 

Images in this story by John Goreham.