It is one of the most common questions we get: “If I buy a 22 kW charger, will my car charge twice as fast as 11 kW?” The honest answer is only if your car can accept 22 kW on AC, and many cannot.
The onboard charger sets the limit
When you charge from a home or portable charger, you are supplying AC power. The car’s onboard charger converts it to DC to fill the battery, and it has a maximum rate. The charger on the wall or the ground simply offers power; the car decides how much to take.
- Many popular EVs sold in Australia accept up to 11 kW on AC (for example, the Tesla Model 3 and Model Y)
- Some accept only around 7 kW, especially single-phase-only models
- A smaller number accept the full 22 kW
DC fast charging works differently. It bypasses the onboard charger, which is why public fast chargers can be so much quicker.
How to check your car
- Look in your owner’s manual or the manufacturer’s spec sheet for “AC charging” or “onboard charger” in kW.
- Check whether it is single-phase or three-phase capable.
- Note that some models offer a faster onboard charger as an option, so check the exact variant.
Not sure? Send us your make, model and year and we will tell you straight.
When 22 kW is still a smart buy
- Your car accepts 22 kW AC
- You plan to upgrade to a car that does
- You share the charger between vehicles, including a work vehicle that accepts 22 kW
Otherwise, an 11 kW charger will charge most three-phase-capable cars at their full AC speed for less money.
Speeds at a glance
- 7.2 kW single-phase: about 30–50 km of range per hour
- 11 kW three-phase: about 45–75 km per hour
- 22 kW three-phase: about 90–150 km per hour, in cars that accept it
Frequently asked questions
Will a 22 kW charger damage a car that only takes 11 kW?
No. The car and charger agree on a safe rate through the control pilot signal, and the car simply takes what it can.
Is 11 kW enough for overnight charging?
For almost everyone, yes. Ten hours at 11 kW is far more energy than a typical day’s driving uses.
Why do public chargers charge faster?
Public DC fast chargers bypass the onboard charger and feed the battery directly.
Key takeaways
- Your car’s onboard charger limits AC charging speed
- Many EVs top out at 11 kW AC; some at 7 kW
- Check your exact model and variant before buying 22 kW
- A higher-rated charger will not harm a car that accepts less