Both AC and DC charging put electricity into your EV’s battery, the difference is where the conversion from AC to DC power happens, and that single difference explains almost everything else about how the two compare: speed, equipment, and where you typically encounter each one.
Why the conversion matters
The electricity grid, and every home outlet, delivers alternating current (AC). An EV’s battery, like any battery, can only store direct current (DC). Somewhere in the process, AC has to be converted to DC. With Level 1 and Level 2 charging, that conversion happens inside the vehicle itself, through a component called the onboard charger. With DC fast charging, the conversion happens inside the charging station before the power ever reaches the car, delivering DC directly to the battery.
| AC charging (Level 1 & 2) | DC fast charging | |
|---|---|---|
| Where conversion happens | Inside the vehicle (onboard charger) | Inside the charging station |
| What limits your speed | Your vehicle’s onboard charger rating, commonly 7 to 11 kW for home charging | Whichever is lower: the station’s max output or your vehicle’s max DC acceptance rate |
| Typical locations | Home, workplace, many public parking areas | Dedicated fast-charging stations along highways and major corridors |
| Typical speed | Roughly 30 to 50 km of range per hour on a home Level 2 unit | 10 to 80% in roughly 20 to 45 minutes |
Why your onboard charger caps AC speed
This is the detail that surprises a lot of new owners: plugging into a more powerful AC source doesn’t necessarily charge faster, because the bottleneck is usually the car’s onboard charger, not the wall. A vehicle with an 11 kW onboard charger will charge at roughly the same speed on an 11 kW home charger as it would on a theoretical 19 kW public AC station, the car simply can’t accept power faster than its onboard charger allows. This is different from DC fast charging, where the conversion equipment lives in the station itself and can deliver power far beyond what any onboard AC charger could handle.
What this means in practice
For daily charging, AC is what you’ll use almost all the time, at home or at work, and it’s plenty fast for overnight charging regardless of your vehicle’s specific onboard charger rating. DC fast charging is the tool for road trips and quick top-ups away from home, where you need a large amount of range added in a short time and are willing to pay a premium per kWh for it.
💡 Tip: If you’re comparing EVs and road trips matter to you, check the vehicle’s maximum DC fast-charging rate specifically, not just its onboard AC charger rating. The two numbers can differ significantly and only one of them affects your road trip charging stops.
⚠️ Note: Not every EV can accept the full output of every DC fast charger. A vehicle rated for 100 kW DC charging won’t charge any faster on a 350 kW station than it would on a 100 kW one, the car’s own limit is what matters.