AC vs. DC Charging: What’s the Difference?

When you plug in an EV, it’s not just about adding power, the type of current matters. EV chargers come in two main types: AC (Alternating Current) and DC (Direct Current). Understanding the difference helps you choose the right charger for your needs.

Project overview

If you’ve ever wondered what the differences are between AC and DC charging (or didn’t even know they existed), then this guide is for you!

Why is it important?

Well, aside from using different currents, knowing the differences between AC and DC chargers can help you charge smarter, save you time and protect your EV’s battery.

The basics: AC vs DC power

Alternating Current (AC)
AC power is the standard form of electricity supplied to homes and commercial buildings. Its current alternates direction, which is why most residential and workplace EV charge points operate using AC as standard.

Direct Current (DC)
DC power on the other hand flows in a single direction. Because EV batteries store energy as DC, DC chargers send power straight to the battery, bypassing the vehicle’s onboard converter. These chargers are typically found at rapid charging stations along motorways and other major routes.

How AC and DC Charging Works

AC charging

AC charging works by converting AC power to DC inside the vehicle using the onboard charger. Because this conversion is limited by the car’s capabilities, charging speeds are slower - typically between 3.7 kW and 22 kW. This makes AC charging best suited to home charging and places where you’ll be parked for several hours, such as workplaces, hotels or shopping centres.

DC charging

DC charging converts AC power to DC within the charging station itself, allowing electricity to be delivered directly to the vehicle’s battery. This enables much faster charging speeds, typically ranging from 50 kW to 350 kW, making DC charging ideal for quick top-ups during long journeys or whenever time is limited.

Key Differences Between AC and DC Charging

Feature	AC Charging	DC Charging
Power Type	Alternating Current (AC)	Direct Current (DC)
Speed	Slow to moderate (3.7–22 kW)	Fast to ultra-fast (50–350 kW)
Conversion	Inside the vehicle	Inside the charger
Typical Locations	Home, workplace, public car parks	Highways, rapid-charging hubs

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Choosing the Right Charger

For daily charging

AC charging is ideal for everyday use. It’s cost-effective, convenient and perfectly suited to overnight or all-day charging.

For road trips or quick boosts

DC rapid charging is the best option when you need to add significant range quickly, often in just a timeframe of 20 to 40 minutes.

For battery longevity

Regular AC charging is generally gentler on your battery. While DC charging is safe and convenient, frequent use can increase heat and long-term battery wear.

Pros and Cons of AC and DC Charging

Charging Type	Pros	Cons
AC Charging	Widely accessible Better for battery health	Slower charging speeds
DC Charging	Fast and efficient Ideal for quick stops	Less common Can be costly Frequent use can impact battery health

Practical Tips for EV Drivers

Plan ahead by using AC charging whenever you have the time and save DC fast charging for longer trips or when you’re in a hurry.

As already mentioned, understand your vehicle’s maximum charging rate and protect your battery’s long-term health by limiting frequent DC fast charging where possible.

Ready to charge smarter?

Take a moment to check your EV’s charging capabilities and map out nearby AC and DC chargers. Have a look at our Charging Map to find your nearest Roam charging station.

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