What does Charging Curve mean?

Explanation

The charging curve is a graph that shows the relationship between your battery's state of charge and the charging power your car accepts at each point. No EV charges at a flat, constant speed from 0% to 100%. Instead, the power ramps up at the start, hits a peak in the low-to-mid SoC range, and then tapers off as the battery fills.

Different cars have very different charging curves. Some maintain high power across a wide range (like the Hyundai Ioniq 5, which holds near-peak power from 10% to about 50%). Others start dropping power early (like some older EVs that taper significantly above 30%). The shape of the curve determines how long a charging stop actually takes.

You will not see the charging curve displayed on the charger itself, but you can feel its effects by watching the kW number change on the charger screen during your session. Reviewers and EV sites publish charging curve graphs for different car models, and these are one of the best tools for planning road trip stops. A car with a flat, high charging curve spends less time at the charger than one with a steep taper.

Learn more from National Renewable Energy Laboratory.

Where you'll see this

• On the charger screen
• On your car dashboard

Common confusion

Many people expect their car to charge at the advertised peak speed the entire time, then think something is wrong when it slows down. The advertised speed is the peak, not the average. Real-world average charging speed is always lower.

Example

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