AC vs DC charging: why the number on the charger isn't the number you get

Start with a sum. Hyundai's German price list says the Ioniq 5 84 kWh goes from 10 to 80% in about 18 min on a 350 kW charger. Seventy per cent of 84 kWh is 58.8 kWh, and 58.8 kWh in that time averages 196 kW.

So the post says 350. The car's rated peak says 260 kW. You get about 196.

Every time in this piece is a maker's rating, not a measurement, and the averages are my arithmetic. Hyundai doesn't say whether its battery figure is usable or gross, so treat 196 as a ceiling. Figures checked 2 November 2026.

Who does the converting

Batteries store direct current. The grid supplies alternating current. On an AC post, the converter is the on-board charger inside your car, as ANWB explains, and that box is small. On a DC post, the conversion has already happened in the station, and go-e's guide says only two limits then count: the car's DC maximum and the station's.

That gives you the first rule. On AC, the car sets the ceiling. Ingenieur.de put it plainly in September 2026: a car with an 11 kW on-board charger takes 11 kW from a 22 kW wallbox.

The EU's fuel observatory sorts posts by their plate: under 7.4 kW is slow AC, 150 kW and up is ultra-fast DC. Those classes describe the post. They tell you nothing about your car.

The plugs differ too. EU rules require Type 2 for AC and CCS for DC, says the same observatory. Dacia's German spec sheet puts CCS in an optional pack on the Spring Expression, so without that pack a fast charger is no use to it at all.

The Spring, line by line

Dacia publishes times from 15 to 80% for the Spring. That window is 65% of 27.5 kWh, or 17.9 kWh. Divide by the time and you get what reaches the battery:

• 50 kW DC, with the pack: about 28 minutes, so 38 kW on average
• 11 kW AC, with the pack: about 1 h 55, so 9.3 kW
• 3.7 kW AC from a reinforced socket: about 5 h 40, so 3.2 kW

Standard AC is 3.7 kW on one phase. Plug the base car into a 22 kW public post and that's still all it takes.

Dacia's table has one more row that doesn't fit: 6.6 kW AC on the standard cable at a 7.4 kW point, about 2 h 55. Its spec sheet lists 3.7 kW on one phase as the standard on-board charger for the Expression and Journey alike, with 11 kW only as an option, and the same charging page says up to 3.7 kW at home. So I go with 3.7 kW. Get 6.6 kW in writing before you count on it.

Dacia doesn't split the gap between plate and average into losses and slowing. I can't either.

Why DC falls so far short

EVKX's glossary gives the reason: power is often lower when the battery is very cold, very warm or nearly full, and the shape of the curve is set by the car. It may climb to a peak, sit on a plateau, then taper. A short high peak can add less energy than a lower rate held for longer.

Look at the Ioniq 5 on a small post. Hyundai rates the same 10 to 80% at about 1 h 16 on 50 kW, an average of 46 kW. That's nearly the whole plate, because the post is the limit and the battery never gets near its own. Move up to 350 kW and the battery takes over.

On AC the gap is narrower. Hyundai gives about 7 h 35 for 10 to 100% at 11 kW. That's 75.6 kWh into the battery, about 10 kW. Hyundai's footnote adds that real times depend on the post, battery temperature and outside temperature.

The part you pay for

Speed isn't the only difference. The running-cost calculator defaults to €0.28/kWh at home (Eurostat EU average, first half of 2026) and €0.55 on public DC (Eleport's October 2026 median, and Eleport runs chargers). The Ioniq's WLTP 16 kWh/100 km plus the calculator's 25% is 20 kWh per 100 km. That's €5.60 at home and €11 on DC.

Double, for the same kilometres. WLTP already counts charging losses, so nothing goes on top. Run it for this car with your own tariff, because Germany's household price, €0.3618 in the same Eurostat series, is well above that average. The home and public sums go further.

How I'd read a spec sheet

For long trips, I'd compare minutes from 10 to 80% at a named charger power, and only between cars quoted over the same window. Peak kW is the last number I'd look at.

For home, I'd check the car's AC limit first, then what your supply can deliver. Would I buy the Spring's pack? Only if the car ever leaves town. A 3.7 kW point covers 65% of the battery while you sleep.