AC vs DC Charging — What's the Difference?

When charging your EV, you'll quickly encounter two terms: AC and DC. The difference between them determines how fast you can charge, what it costs, and when you should use which type. Here's a simple and practical explanation.

What Are AC and DC?

AC stands for alternating current, and DC stands for direct current. The power grid in Norway delivers AC — that's what comes out of the wall socket at home. Your EV's battery, however, stores energy as DC.

This means the power must be converted from AC to DC before it can be stored in the battery. The question is simply where this conversion happens — and that's where the difference between AC and DC charging lies.

How AC Charging Works

When you charge with AC, the charging station (or home charger) sends alternating current to the car. The car has a built-in charger — called an onboard charger — that converts AC to DC before the power reaches the battery.

This built-in charger has limited capacity, typically between 7.4 kW and 22 kW depending on the car model. That's why AC charging is relatively slow compared to fast charging.

Typical AC power levels:

• Standard wall outlet (Schuko): 2.3 kW — approx. 15–20 hours for a full charge
• Home wallbox (single-phase): 7.4 kW — approx. 5–8 hours
• Home wallbox (three-phase): 11–22 kW — approx. 2–5 hours
• Public AC charging point: 11–22 kW

How DC Charging (Fast Charging) Works

DC charging — also called fast charging — works quite differently. Here, the charging station delivers direct current straight to the battery, completely bypassing the car's onboard charger.

Because the charging station handles the conversion itself, it can deliver much higher power. Modern DC fast chargers deliver from 50 kW all the way up to 350 kW.

Typical DC power levels:

• Older fast chargers: 50 kW — approx. 45–60 min (20–80%)
• Standard fast chargers: 150 kW — approx. 20–30 min (20–80%)
• Ultra-fast chargers: 250–350 kW — approx. 10–20 min (20–80%)

Why Is DC So Much Faster?

The answer is simple: the car's onboard charger is the bottleneck with AC charging. When you charge with DC, you bypass this bottleneck and feed power directly into the battery at whatever rate the charging station and the car's battery management system allow.

Think of it this way: AC charging is like filling a bathtub with a garden hose. DC charging is like using a fire hose. Both fill the tub, but the time difference is enormous.

When Should You Use AC vs DC?

Choose AC charging when:

• You're charging at home overnight — the car's onboard charger has plenty of time, and electricity prices are often lowest at night
• You're parked for a long time — at work, at a shopping centre, or at a hotel
• You want to save money — home charging at spot price can cost as little as 0,50 kr/kWh per kWh, while fast charging typically costs 2,50 kr/kWh to 5,00 kr/kWh per kWh

Choose DC charging when:

• You're on a road trip — fast charging along the way is the only practical option
• You need a quick top-up — 20 minutes on a 150 kW charger gives you 150–200 km of range
• You don't have a home charger — many apartment dwellers depend on public charging

What Does AC vs DC Cost in Practice?

Let's take a concrete example. You have an EV with a 77 kWh battery and want to charge from 20% to 80% (approx. 46 kWh):

Home charging (AC):

• Spot price + grid tariff: approx. 1,20 kr/kWh per kWh on average
• Total cost: approx. 55 kr

Fast charging (DC):

• Cheapest operator (registered price, 2026): approx. 2,59 kr/kWh per kWh
• Total cost: approx. 119 kr
• Most expensive operator: up to 4,99 kr/kWh per kWh — approx. 230 kr

The difference is roughly 65–175 kr per charging session. Over a year with weekly charging, that's 3,400–9,100 kr.

Use the home charging calculator→ to calculate exactly what charging costs in your price zone.

Charging Connectors for AC and DC

AC charging in Europe uses the Type 2 connector. It sits in the car's charging port and is used for both home charging and public AC charging points.

DC fast charging uses CCS Combo 2 (Combined Charging System). This builds on Type 2 with two extra contact pins for high-power direct current. All newer EVs in Norway use CCS.

Older Nissan Leaf and Mitsubishi Outlander models use CHAdeMO for DC, but this is being phased out.

Does DC Charging Wear Down the Battery?

A common question is whether frequent fast charging wears down the battery. The answer is nuanced:

• Modern EVs have advanced battery management that protects against overheating
• Regular fast charging in extreme cold or heat can marginally accelerate ageing
• For most people, a mix of home charging (daily) and fast charging (on trips) is perfectly fine
• Battery manufacturers design for at least 70% capacity after 8 years / 160,000 km

Summary

For most Norwegian EV owners, the ideal strategy is simple: charge at home when you can (cheap AC), and use fast charging when you need to (fast DC).