Our long-term Kia EV6 test car has an excellent charging curve

If you’ve done much charging of electric cars, you’re probably already familiar with the term “charging curve.” It’s not something you’ll see manufacturers drop in press releases often, but it’s definitely going to be impactful to your fast-charging experience at public charging stations.

Battery packs in cars (and lithium-ion battery packs everywhere) can’t charge at the same speed 100% of the time, largely due to heat constraints. In layman’s terms, the closer to capacity you get, the hotter the battery pack becomes, and the slower you’re going to charge as a result. That means that even though your EV might be rated for a maximum charge rate of 235 kW, it won’t charge at 235 kW from 0-100% the whole time. If conditions (and the charger) allow it, you’ll hopefully see the car charge at or near the maximum rate for a good bit before it slows down as the battery gains more and more charge. If you wait for it to trickle up to 100%, the charge rate will have dropped off to a dribble by the time you get there.

Of course, the most ideal situation that would produce the shortest charge times is for a car to have a charge curve that stays high for as long as possible, minimizing the amount of time you spend charging at a lower speed. This leads to less overall time spent waiting around at a charger, which is always a plus in our book.

We’ve had our 2022 Kia EV6 GT-Line AWD long-term test car for a good number of months now and done a lot of fast-charging sessions with it where the car charges at its peak speed. So we’ve experienced the EV6’s charge curve time and time again, allowing us to get a good idea of what the EV6 can do.

Kia claims the EV6’s peak charge speed is 235 kW, which if you take a gander through our list of fastest-charging electric cars, is actually quite good. Thankfully, the charge curve has proved to be quite good, too. Our EV6 quickly shoots up to its maximum charging speed soon after plugging in, and has frequently displayed charge speeds in the cluster’s readout that are even higher than the quoted 235 kW maximum.

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From zero to approximately 55%, the EV6 hovers around the 220-230 kW charge speed range — that’s really good! Once you get beyond 60%, the rate drops to approximately 190 kW. Move beyond 70%, and the steady slowdown is in full effect. By the time you’ve hit 80% — the typical point at which EVs hit a wall in charge speed these days — the speed has moved under 150 kW, and it keeps going down from here.

Before you scoff at that 150 kW charge speed from 70-80%, allow us to remind you that lots of EVs have charge speeds that max out right around 150 kW, and they’re subject to their own unique charging curves. To name a few competitors, the Ford Mustang Mach-E and Volkswagen ID.4 both have max charging speeds at or under 150 kW.

When it comes to a charge curve that produces quick fast-charging stops on road trips or quick top-ups alike, the EV6 is an awesome companion. Going from 10-80% on a charger that is working as it should (that’s no guarantee) only takes about 15-20 minutes. If you wait for that final 20% to get up to a full charge, it’s going to be another 15-20 minutes of waiting, but that’s very normal for EVs.

When you compare it to other modern EVs — as is done in this ArenaEV charging test — the EV6 stays looking like a champion. The lesson learned through experience and data here is that the EV6 has an excellent and very user-friendly charging curve, so fast-charge away!

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