One of the most common questions when buying an EV charger is whether to choose a 7kW or 22kW model. Many people assume a more powerful charger will always charge their car faster — but that's not always true. The maximum charging speed is limited by both the charger and your car's onboard charger (the converter inside the vehicle that turns AC power into DC for the battery). A 22kW charger can only deliver its full power if your car is capable of accepting 22kW.
How EV Charging Speed Really Works
Your car's onboard charger determines the maximum AC charging rate it can handle. Many popular EVs have an 11kW onboard charger — so even if you install a 22kW EV charger, they will only charge at up to 11kW. Higher-end or newer models can accept the full 22kW.
Key takeaway: A 22kW charger is only worth it if your current (or future) car can actually use most of that power.
Real-World EV Charging Speeds
| Vehicle Onboard Charger | Charger Installed | Actual Charging Speed | Miles of Range per Hour | Full Charge Time (60kWh battery) |
|---|---|---|---|---|
| 7.4kW | 7kW | 7.4kW | ~20–25 miles | 8–10 hours |
| 11kW | 7kW | 7kW | ~20–25 miles | 8–10 hours |
| 11kW | 22kW | 11kW | ~35–40 miles | 5–6 hours |
| 22kW capable | 22kW | 22kW | ~70–100 miles | 2.5–4 hours |
7kW vs 22kW EV Charger Comparison
| Factor | 7kW EV Charger | 22kW EV Charger |
|---|---|---|
| Max Speed (limited by car) | Up to 7.4kW | Up to 22kW (only if car supports it) |
| Best For | Overnight home charging | Faster daytime top-ups, busy workplaces |
| Power Supply Required | Single-phase (most UK homes) | Three-phase supply |
| Installation Cost | Lower | Higher (especially if three-phase upgrade needed) |
| Unit Price | Cheaper | £100–£300 more expensive |
| Future-proofing | Good for most homes | Better if you own or plan to buy 22kW-capable cars |
| Suitability for Workplace | Fine for all-day parking | Excellent for higher turnover bays |
Best Use Cases for 7kW Chargers
- Most UK family homes with single-phase electricity
- Properties where cars are parked for 6–10 hours (overnight or full workday)
- Budget-conscious buyers or first-time EV owners
- Situations where your car's onboard charger is 7.4kW or 11kW
Ideal for: The majority of residential users.
Best Use Cases for 22kW Chargers
- Homes or businesses with an existing three-phase supply
- Workplaces with higher vehicle turnover (staff coming and going during the day)
- Drivers who own (or plan to buy) vehicles capable of 22kW AC charging
- Fleets or commercial sites wanting faster charging
Ideal for: Commercial properties and homes with three-phase power.
Our Recommendations
Most homeowners
Start with a 7kW charger unless you already have three-phase power and a car that can accept 22kW.
Businesses & workplaces
Strongly consider 22kW if you have (or can install) three-phase power and need faster turnaround.
Unsure?
Get an electrician to check your supply and confirm your car's onboard charger limit.
FAQs
Will a 22kW charger charge my car twice as fast as a 7kW?
Not necessarily. It depends on your car's onboard charger. Many EVs are limited to 7kW or 11kW, so the benefit may be smaller than expected.
How do I know what my car can accept?
Check your vehicle's handbook or specifications online. Search for "maximum AC charging rate" for your model.
Is it worth upgrading to three-phase for a 22kW charger?
It depends on how often you need fast charging and whether you plan to own higher-power vehicles in the future.
Can I install a 22kW charger on a single-phase supply?
No — 22kW requires a three-phase connection.
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